COMPOSITIONS AND METHODS FOR CANCER EXPRESSING PDE3A OR SLFN12

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of U.S. Provisional Application No.

62/204,875 filed August 13, 2015, the disclosure of which is incorporated herein by reference in its entirety.

STATEMENT OF RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED

RESEARCH

This invention was made with Government support under Grant No. 3U54HG005032 'awarded by the National Institutes of Health. The Government has certain rights in the invention.

BACKGROUND OF THE INVENTION

Cancer kills over 550,000 people in the United States and over 8 million people world-wide each year. New agents, including small molecules, molecules that impact tissue-specific growth requirements, and immunomodulatory agents, have been shown to benefit a subset of patients whose cancers have unique genomic mutations or other characteristics. Unfortunately, many cancer patients are still left without effective therapeutic options.

One approach to identify new anti-cancer agents is phenotypic screening to discover novel small molecules displaying strong selectivity between cancer cell lines, followed by chemogenomics to identify the cell features associated with drug response. In the 1990s, Weinstein and colleagues demonstrated that the cytotoxic profile of a compound can be used to identify cellular characteristics, such as gene-expression profiles and DNA copy number that correlate with drug sensitivity. The ability to identify the features of cancer cell lines that mediate their response to small molecules has strongly increased in recent years with automated high-throughput chemosensitivity testing of large panels of cell lines coupled with comprehensive genomic and phenotypic characterization of the cell lines. Phenotypic observations of small-molecule sensitivity can be linked to expression patterns or somatic alterations, as in the case of SLFN11 expression in cancer cell lines sensitive to irinotecan treatment, and an EWS-FLI1 rearrangement in cancer cell lines sensitive to PARP inhibitors, respectively.

Methods of characterizing malignancies at a molecular level are useful for stratifying patients, thereby quickly directing them to effective therapies. Improved methods for characterizing the responsiveness of subj ects having cancer are urgently required.

SUMMARY OF THE INVENTION As described below, the present invention features methods of identifying patients having a cancer (e.g., melanoma, adenocarcinoma, lung, cervical, liver, endometrium, lung, hematopoetic / lymphoid, ovarian, cervical, soft-tissue sarcoma, leiomyosarcoma, urinary tract, pancreas, thyroid, kidney, glioblastoma, or breast cancer) that is sensitive to treatment with a phosphodiesterase 3 A (PDE3A) modulator (e.g., 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)- one, zardaverine, and anagrelide) by detecting co-expression of PDE3A and Schlafen 12 (SLFN12) polynucleotides or polypeptides in a cancer cell derived from such patients.

In one embodiment, the present invention provides a method of killing or reducing the survival of a cancer cell selected as responsive to a phosphodiesterase 3 A (PDE3 A) modulator. The method includes the step of contacting the cell with a PDE3 A modulator, where the cell was selected as having an increase in PDE3A and/or Schlafen 12 (SLFN12) polypeptide or polynucleotide relative to a reference, thereby reducing the survival of the cancer cell. In another embodiment, the present invention provides a method of reducing cancer cell proliferation in a subject pre-selected as having a cancer that is responsive to a PDE3A modulator. The method comprises administering to the subject a PDE3A modulator, wherein the subject is pre-selected by detecting an increase in PDE3A and/or SLFN12 polypeptide or polynucleotide levels relative to a reference, thereby reducing cancer cell proliferation in the subject. In one embodiment, the subject is pre-selected by detecting an increase in PDE3A and/or SLFN12 polypeptide or polynucleotide levels. In some embodiments, the PDE3A modulator is selected from the group consisting of 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5- dihydropyridazin-3(2H)-one (DNMDP), zardaverine, and anagrelide.

In another embodiment, the present invention provides a method of identifying a subject having a cancer responsive to PDE3A modulation. The method includes the step of detecting an increase in the level of a PDE3A and/or SLFN12 polypeptide or polynucleotide in a biological sample of the subject relative to a reference, thereby identifying the subject as responsive to PDE3A modulation. In one embodiment, an increase in the level of PDE3A and SFLN1 polypeptide or polynucleotide is detected.

In some embodiments, the increase in the level of PDE3A and/or SLFN12 polypeptide is detected by a method selected from the group consisting of immunob lotting, mass spectrometry, and immunoprecipitation. In some other embodiments, the increase in the level of PDE3A, and/or SLFN12 polynucleotide is detected by a method selected from the group consisting of quantitative

PCR, Northern Blot, microarray, mass spectrometry, and in situ hybridization. In some embodiments, the activity of PDE3 A is reduced. The PDE3 A modulator may be administered orally. The PDE3A modulator may be administered by intravenous injection.

In some embodiments, the cancer cell is a melanoma, endometrium, lung, hematopoetic / lymphoid, ovarian, cervical, soft -tissue sarcoma, leiomyosarcoma, urinary tract, pancreas, thyroid, kidney, glioblastoma, or breast cancer. In some other embodiments, the cancer cell is not a B-cell proliferative type cancer. In some embodiments, the cancer cell is not multiple myeloma. In some embodiments, the biological sample is a tissue sample.

In another aspect, the present invention provides a kit for identifying a subject having cancer as responsive to PD3A modulation, the kit comprising a capture reagent that binds PDE3A and/or a capture reagent that binds SLFN12. In one embodiment, the kit comprises a capture reagent that binds PDE3A and a capture reagent that binds SLFN12.

In yet another aspect, the present invention provides a kit for decreasing cancer cell proliferation in a subject pre-selected as responsive to a PDE3A modulator, the kit comprising DNMDP, zardaverine, and/or anagrelide.

The invention provides methods for treating subjects having cancer identified as responsive to treatment with a PDE3A modulator by detecting co-expression of PDE3A and/or Schlafen 12 (SLFN12) polynucleotides or polypeptides in the cancer. Compositions and articles defined by the invention were isolated or otherwise manufactured in connection with the examples provided below. Other features and advantages of the invention will be apparent from the detailed description, and from the claims.

Definitions

Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by a person skilled in the art to which this invention belongs. The following references provide one of skill with a general definition of many of the terms used in this invention: Singleton et al., Dictionary of Microbiology and Molecular Biology (2nd ed. 1994); The Cambridge Dictionary of Science and Technology (Walker ed., 1988); The Glossary of Genetics, 5th Ed., R. Rieger et al. (eds.), Springer Verlag (1991); and Hale & Marham, The Harper Collins Dictionary of Biology (1991). As used herein, the following terms have the meanings ascribed to them below, unless specified otherwise.

By "Anagrelide" (IUPAC Name 6,7-dichloro-l ,5-dihydroimidazo (2, l -b)quinazolin-2(3//)- one) is meant a small molecule phosphodiesterase inhibitor having the following structure:

By "Cilostamide" (IUPAC Name -cyclohexyl-A^-methyl-4-[(2-oxo-l/ -quinolin-6- yl)oxy]butanamide) is meant a small molecule inhibitor having the following structure:

By "Cilostazol" (IUPAC Name 6-[4-(l -cyclohexyl- l /-tetrazol-5-yl)butoxy]-3,4-dihyd] -quinolinone) is meant a small molecule inhibitor having the following structure:

By "DNDMP" (IUPAC Name 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5- dihydropyridazin-3(2H)-one) is meant a small molecule inhibitor having the following structure:

By "Forskolin" (IUPAC Name (3R,4aR,5S,6-?,6aS,10S,10aR, 10b5)-6,10, 10b-Trihydroxy- 3,4a,7,7,10a-pentamethyl-l -oxo-3-vinyldodecahydro-l/ -benzo[ ]chromen-5-ylacetate) is meant a small molecule inhibitor having the following structure:

By "Levosimendan" (IUPAC Name (E)-2-cyano-l-methyl-3-(4-(4-methyl-6-oxo-l ,4,5,6- tetrahydropyridazin-3-yl)phenyl)guanidine) is meant a small molecule inhibitor having the following structure:

By "Milrinone" (IUPAC Name 2-methyl-6-oxo-l,6-dihydro-3,4'-bipyridine-5-carbonitrile) is meant a small molecule inhibitor having the following structure:

By "Papaverine" (IUPAC Name l-(3,4-dimethoxybenzyl)-6,7-dimethoxyisoquinoline) is meant a small molecule inhibitor having the following structure:

By "Siguazodan" (IUPAC Name (E)-2-cyano-l-methyl-3-(4-(4-methyl-6-oxo- 1,4,5,6- tetrahydropyridazin-3-yl)phenyl)guanidine) is meant a small molecule inhibitor having the following structure:

By "Sildenafil" (IUPAC Name l-[4-ethoxy-3-(6,7-dihydro-l-methyl-7-oxo-3-propyl-li - pyrazolo[4,3-i ]pyrimidin-5-yl)phenylsulfonyl]-4-methylpiperazine) is meant a small molecule inhibitor having the following structure:

By "Trequinsin" (IUPAC Name 9,10-dimethoxy-3-methyl-2-(2,4,6-trimethylphenyl)imino-6,7- dihydropyrimido[6, l -a]isoqufnolin-4-one) is meant a small molecule inhibitor having the following structure:

By "Vardenifil" (IUPAC Name 4-[2-ethoxy-5-(4-ethylpiperazin-l-yl)sulfonyl-phenyl]-9-meth yl- 7-propyl-3,5,6,8-tetrazabicyclo[4.3.0]nona-3,7,9-trien-2-one ) is meant a small molecule inhibitor having the following structure:

By "Zardaverine (IUPAC Name 3 -[4-(Difluoromethoxy)-3-methoxyphenyl]- l f-pyridazin-6- one)" is meant a small molecule inhibitor having the following structure:

In some other embodiments, any one of the compounds Cilostamide, Cilostazol, DNDMP, Levosimendan, Milrinone, Papaverine, Siguazodan, Sildenafil, Trequinsin, Vardenifil, and Zardaverine is a small molecule phosphodiesterase inhibitor. In another embodiment, forskolin may be used in a method of the invention.

By "PDE3A polypeptide" is meant a protein or fragment thereof having at least 85% amino acid sequence identity to the sequence provided at NCBI Ref No. NP_000912.3 that catalyzes the hydrolysis of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate

(cGMP). An exemplary human full-length PDE3A amino acid sequence is provided below:

MAVPGDAARVRD PVHSGVSQAPTAGRDCHHRADPASPRDSGCRGCWGDLVLQPLRSSRKLSSALCAGSLSFL LA LLVRLVRGEVGCDLEQCKEAAAAEEEEAAPGAEGGVFPGPRGGAPGGGARLSPWLQPSAL LFSLLCAFFWMGLYL LRAGVRLPLAVALLAACCGGEALVQIGLGVGEDHLLSLPAAGWLSCLAAAT LVLRLRLGVLMIALTSAVRTVS LISLERFKVAWRPYLAYLAGVLGILLARYVEQILPQSAEAAPREHLGSQLIAGTKEDIPV F RRRRSSSWSAEM SGCSSKSHRRTSLPCIPREQLMGHSEWDHKRGPRGSQSSGTSITVDIAVMGEAHGLITDL LADPSLPPNVCTSLR AVSNLLSTQLTFQAIHKPRTOPVTSLSENYTCSDSEESSEKDKLAIPKRLRRSLPPGLLR RVSSTWTTTTSATGL PTLEPAPVRRDRSTSIKLQEAPSSSPDSWNNPVMMTLTKSRSFTSSYAISAANHVKAKKQ SRPGALAKISPLSSP CSSPLQGTPASSLVSKISAVQFPESADTTAKQSLGSHRALTYTQSAPDLSPQILTPPVIC SSCGRPYSQGNPADE PLERSGVATRTPSRTDDTAQVTSDYETNNNSDSSDIVQNEDETECLREPLRKASACSTYA PETM FLDKPILAPE PLVMDNLDSIMEQLNTWNFPIFDLVENIGRKCGRILSQVSYRLFEDMGLFEAFKIPIREF MNYFHALEIGYRDIP YHNRIHATDVLHAV YLTTQPIPGLSTVINDHGSTSDSDSDSGFTHGHMGYVFSKTY VTDDKYGCLSGNIPALE LMALYVAAAMHDYDHPGRTNAFLVATSAPQAVLYNDRSVLENHHAAAAWNLFMSRPEYNF LINLDHVEFKHFRFL VIEAILATDLKKHFDFVAKFNGKV DDVGIDWTNENDRLLVCQMCIKLADINGPAKCKELHLQWTDGIVNEFYEQ GDEEASLGLPISPFMDRSAPQLANLQESFISHIVGPLCNSYDSAGLMPGKWVEDSDESGD TDDPEEEEEEAPAPN EEETCEMNESPKKKTFKRRKIYCQITQHLLQNHKMWKKVIEEEQRLAGIENQSLDQTPQS HSSEQIQAIKEEEEE KGKPRGEEIPTQKPDQ (SEQ ID NO . : 3 )

Three PDE3A isoforms are known: PDE3A1 , PDE3A2, and PDE3A3. PDE3A1 comprises amino acids 146-1 141, PDE3A2 isoform 2 comprises amino acids 299-1 141 , and PDE3 A3 comprises amino acids 483-1 141 of the full-length PDE3A amino acid sequence.

By "PDE3A polynucleotide" is meant any nucleic acid molecule, including DNA and RNA, encoding a PDE3A polypeptide or fragment thereof. An exemplary PDE3A nucleic acid sequence is provided at NCBI Ref: NMJD00921.4:

1 gggggccact gggaattcag tgaagagggc accctatacc atggcagtgc ccggcgacgc

61 tgcacgagtc agggacaagc ccgtccacag tggggtgagt caagccccca cggcgggccg

121 ggactgccac catcgtgcgg accccgcatc gccgcgggac tcgggctgcc gtggctgctg 181 gggagacctg gtgctgcagc cgctccggag ctctcggaaa ctttcctccg cgctgtgcgc 241 gggctccctg tcctttctgc tggcgctgct ggtgaggctg gtccgcgggg aggtcggctg 301 tgacctggag cagtgtaagg aggcggcggc ggcggaggag gaggaagcag ccccgggagc 361 agaagggggc gtcttcccgg ggcctcgggg aggtgctccc gggggcggtg cgcggctcag 421 cccctggctg cagccctcgg cgctgctctt cagtctcctg tgtgccttct tctggatggg 481 cttgtacctc ctgcgcgccg gggtgcgcct gcctctggct gtcgcgctgc tggccgcctg 541 ctgcgggggg gaagcgctcg tccagattgg gctgggcgtc ggggaggatc acttactctc 601 actccccgcc gcgggggtgg tgctcagctg cttggccgcc gcgacatggc tggtgctgag 661 gctgaggctg ggcgtcctca tgatcgcctt gactagcgcg gtcaggaccg tgtccctcat 721 ttccttagag aggttcaagg tcgcctggag accttacctg gcgtacctgg ccggcgtgct 781 ggggatcctc ttggccaggt acgtggaaca aatcttgccg cagtccgcgg aggcggctcc 841 aagggagcat ttggggtccc agctgattgc tgggaccaag gaagatatcc cggtgtttaa 901 gaggaggagg cggtccagct ccgtcgtgtc cgccgagatg tccggctgca gcagcaagtc 961 ccatcggagg acctccctgc cctgtatacc gagggaacag ctcatggggc attcagaatg 1021 ggaccacaaa cgagggccaa gaggatcaca gtcttcagga accagtatta ctgtggacat 1081 cgccgtcatg ggcgaggccc acggcctcat taccgacctc ctggcagacc cttctcttcc 1141 accaaacgtg tgcacatcct tgagagccgt gagcaacttg ctcagcacac agctcacctt 1201 ccaggccatt cacaagccca gagtgaatcc cgtcacttcg ctcagtgaaa actatacctg 1261 ttctgactct gaagagagct ctgaaaaaga caagcttgct attccaaagc gcctgagaag 1321 gagtttgcct cctggcttgt tgagacgagt ttcttccact tggaccacca ccacctcggc 1381 cacaggtcta cccaccttgg agcctgcacc agtacggaga gaccgcagca ccagcatcaa 1441 actgcaggaa gcaccttcat ccagtcctga ttcttggaat aatccagtga tgatgaccct 1501 caccaaaagc agatccttta cttcatccta tgctatttct gcagctaacc atgtaaaggc 1561 taaaaagcaa agtcgaccag gtgccctcgc taaaatttca cctctttcat cgccctgctc 1621 ctcacctctc caagggactc ctgccagcag cctggtcagc aaaatttctg cagtgcagtt 1681 tccagaatct gctgacacaa ctgccaaaca aagcctaggt tctcacaggg ccttaactta 1741 cactcagagt gccccagacc tatcccctca aatcctgact ccacctgtta tatgtagcag 1801 ctgtggcaga ccatattccc aagggaatcc tgctgatgag cccctggaga gaagtggggt 1861 agccactcgg acaccaagta gaacagatga cactgctcaa gttacctctg attatgaaac 1921 caataacaac agtgacagca gtgacattgt acagaatgaa gatgaaacag agtgcctgag 1981 agagcctctg aggaaagcat cggcttgcag cacctatgct cctgagacca tgatgtttct 2041 ggacaaacca attcttgctc ccgaacctct tgtcatggat aacctggact caattatgga 2101 gcagctaaat acttggaatt ttccaatttt tgatttagtg gaaaatatag gaagaaaatg 2161 tggccgtatt cttagtcagg tatcttacag actttttgaa gacatgggcc tctttgaagc 2221 ttttaaaatt ccaattaggg aatttatgaa ttattttcat gctttggaga ttggatatag 2281 ggatattcct tatcataaca gaatccatgc cactgatgtt ttacatgctg tttggtatct 2341 tactacacag cctattccag gcctctcaac tgtgattaat gatcatggtt caaccagtga 2401 ttcagattct gacagtggat ttacacatgg acatatggga tatgtattct caaaaacgta 2461 taatgtgaca gatgataaat acggatgtct gtctgggaat atccctgcct tggagttgat 2521 ggcgctgtat gtggctgcag ccatgcacga ttatgatcat ccaggaagga ctaatgcttt 2581 cctggttgca actagtgctc ctcaggcggt gctatataac gatcgttcag ttttggagaa 2641 tcatcacgca gctgctgcat ggaatctttt catgtcccgg ccagagtata acttcttaat 2701 taaccttgac catgtggaat ttaagcattt ccgtttcctt gtcattgaag caattttggc 2761 cactgacctg aagaaacact ttgacttcgt agccaaattt aatggcaagg taaatgatga 2821 tgttggaata gattggacca atgaaaatga tcgtctactg gtttgtcaaa tgtgtataaa 2881 gttggctgat atcaatggtc cagctaaatg taaagaactc catcttcagt ggacagatgg 2941 tattgtcaat gaattttatg aacagggtga tgaagaggcc agccttggat tacccataag 3001 ccccttcatg gatcgttctg ctcctcagct ggccaacctt caggaatcct tcatctctca 3061 cattgtgggg cctctgtgca actcctatga ttcagcagga ctaatgcctg gaaaatgggt 3121 ggaagacagc gatgagtcag gagatactga tgacccagaa gaagaggagg aagaagcacc 3181 agcaccaaat gaagaggaaa cctgtgaaaa taatgaatct ccaaaaaaga agactttcaa 3241 aaggagaaaa atctactgcc aaataactca gcacctctta cagaaccaca agatgtggaa 3301 gaaagtcatt gaagaggagc aacggttggc aggcatagaa aatcaatccc tggaccagac 3361 ccctcagtcg cactcttcag aacagatcca ggctatcaag gaagaagaag aagagaaagg 3421 gaaaccaaga ggcgaggaga taccaaccca aaagccagac cagtgacaat ggatagaatg 3481 ggctgtgttt ccaaacagat tgacttgtca aagactctct tcaagccagc acaacattta 3541 gacacaacac tgtagaaatt tgagatgggc aaatggctat tgcattttgg gattcttcgc 3601 attttgtgtg tatattttta cagtgaggta cattgttaaa aactttttgc tcaaagaagc 3661 tttcacattg caacaccagc ttctaaggat tttttaagga gggaatatat atgtgtgtgt 3721 gtatataagc tcccacatag atacatgtaa aacatattca cacccatgca cgcacacaca 3781 tacacactga aggccacgat tgctggctcc acaatttagt aacatttata ttaagatata 3841 tatatagtgg tcactgtgat ataataaatc ataaaggaaa ccaaatcaca aaggagatgg 3901 tgtggcttag caaggaaaca gtgcaggaaa tgtaggttac caactaagca gcttttgctc 3961 ttagtactga gggatgaaag ttccagagca ttatttgaat tctgatacat cctgccaaca 4021 ctgtgtgtgt gtgtgtgtgt gtgtgtgtgt gtgtgtgtgt gtgtgaaaga gagacagaag 4081 ggaatggttt gagagggtgc ttgtgtgcat gtgtgtgcat atgtaaagag atttttgtgg 4141 tttaagtaac tcagaatagc tgtagcaaat gactgaatac atgtgaacaa acagaaggaa 4201 gttcactctg gagtgtcttt gggaggcagc cattccaaat gccctcctcc atttagcttc 4261 aataaagggc cttttgctga tggagggcac tcaagggctg ggtgagaggg ccacgtgttt 4321 ggtattacat tactgctatg caccacttga aggagctcta tcaccagcct caaacccgaa 4381 agactgaggc attttccagt ctacttgcct aatgaatgta taggaactgt ctatgagtat 4441 ggatgtcact caactaagat caaatcacca tttaagggga tggcattctt tatacctaaa 4501 cacctaagag ctgaagtcag gtcttttaat caggttagaa ttctaaatga tgccagagaa 4561 ggcttgggaa attgtacttc agcgtgatag cctgtgtctt cttaatttgc tgcaaaatat 4621 gtggtagaga aagaaaagga aacagaaaaa tcactctggg ttatatagca agagatgaag 4681 gagaatattt caacacaggg tttttgtgtt gacataggaa aagcctgatt cttggcaact 4741 gttgtagttt gtctttcagg ggtgaaggtc ccactgacaa cccctgttgt ggtgttccac 4801 acgctgtttg ttggggtagc ttccatcggc agtctggccc attgtcagtc atgcttcttc 4861 tggccgggga gattatagag agattgtttg aagattgggt tattattgaa agtctttttt 4921 tttgtttgtt ttgttttggt ttgtttgttt atctacactt gtttatgctg tgagccaaac 4981 ctctatttaa aaagttgata ctcactttca atattttatt tcatattatt atatatgtca 5041 tgatagttat cttgatgtaa atatgaagat ttttttgttt ctgtagatag taaactcttt 5101 ttttaaaaaa ggaaaaggga aacattttta taaagttata ttttaatcac catttttata 5161 cattgtagtt ctctccaagc ccagtaagag aatgatgatt catttgcatg gaggtcgatg 5221 gacaaccaat catctacctt ttctaattta aatgataatc tgatatagtt ttattgccag 5281 ttaaatgagg atgctgcaaa gcatgttttt tcactagtaa cttttgctaa ctgaatgaat 5341 tctgggtcca tatctcccag atgaaaaact gttaaccaat accatatttt atagttggtg 5401 tccatttctt tccaacactg tttgttatga ttcttccttg agtacttata tacagacctg 5461 ctcattatct aaacaatctt accttctaag taaaccttga ttgtgatttc cagtttttat 5521 tttctctgac gtagtagaaa ggaatgttta cattaaaaat acttttgttt ctcataaatg 5581 gatattgtac tccccccttt caaagcatta ttttacaata attcatggca ttttaaaaaa 5641 taaggcaaag ataatacgac aaaaaatata catggtttca aggcaaattc tccaataagt 5701 tggaaaatgt aaaaaggatc aagtggatgc agcctctacc taaataatta aaatatattt 5761 cagtatattt ctgaattaac accaggtctt cattatttag aacttactaa attgttttca 5821 ttttcttagt tttacctgtg tatctccatg tttgcaaaaa ttactataag tcaaattttg 5881 ccagtgaatt taactatttt tctttccttg caattaaggg gaaaaaagca tttatcttat 5941 cttctcatac cccttgcatc taagtactta gcaaagtcaa tattttccca ttttccaaat 6001 gcgtccatct ctaacataaa tattaattga acatagagct atgtttggag tgagtggact 6061 ggcaggacag ttggaagtcc atcacagtct attgacagtt tcatcaaagc tgtatagtcc 6121 aactagtggg gcagcttggc tactatggtg gaagtctcag caaactgcct ggttttgttt 6181 gtttgttttg ttttaaggta caggaaataa gaggaataat agtggccaaa gcaattagaa 6241 catcttcatt ccagaactgt gttcagcaat ccaggcagat tgatacattt ttctttaaaa 6301 ataaattgct attacagcta gacgtcaatt gggataaata aagggatgaa gatccactaa 6361 gtttgtgact ttcatacaca cccagtacat ctcaaaggat gctaagggac attttctgcc 6421 agtagagttc tccccctttt tggtgacagc aatattatta tgttcacatc taactccaga 6481 gcttacttcc tgtggtgcca atgtatttgt tgcaatttac tacattttta tatgagccta 6541 tttataggtg ccattaaact caggtctttc aaatgaaaga gtttctagcc cacttaggga 6601 aaaagataat tgtttagaaa accataaaat caatggtagg aaaagttgga actggttacc 6661 tggatgccat ggttctctgt taaataaagt aagagaccag gtgtattctg agtgtcatca 6721 gtgttatttt cagcatgcta ataaatgtct ttccggttat atatctatct aaattaacct 6781 ttaaaatatt ggtttccttg ataaaagcac cacttttgct tttgttagct gtaatatttt 6841 ttgtcattta gataagacct ggtttggctc tcaataaaag atgaagacag tagctctgta 6901 cagggatata tctatattag tcttcatctg atgaatgaag aaattttctc atattatgtt 6961 caagaaagta tttacttcct aaaaatagaa ttcccgattc tgtctatttt ggttgaatac 7021 cagaacaaat ctttccgttg caatcccagt aaaacgaaag aaaaggaata tcttacagac 7081 tgttcatatt agatgtatgt agactgttaa tttgcaattt ccccatattt cctgcctatc 7141 ttacccagat aactttcttt gaaggtaaaa gctgtgcaaa aggcatgaga ctcaggccta 7201 ctctttgttt aaatgatgga aaaatataaa ttattttcta agtaataaaa gtataaaaat 7261 tatcattata aataaagtct aaagtttgaa attattaatt taaaaaaaaa aaaaaaaaa (SEQ ID NO. : 4)

By "Schlafen 12 (SLFN12) polypeptide" is meant a protein or fragment thereof having at least 85% amino acid sequence identity to the sequence provided at NCBI Ref No. NP_060512.3 that interacts with PDE3 A when bound to anagrelide, zardaverine or DNMDP and related compounds. An exemplary human SLFN12 amino acid sequence is provided below:

MNISVDLETNYAELVLDVGRVTLGENSRKKMKDCKLRKKQNESVSRAMCALLNSGGGVIK AEIENEDYSYTKDGI GLDLENSFSNILLFVPEYLDFMQNGNYFLIFVKSWSLNTSGLRITTLSSNLYKRDITSAK VMNATAALEFLKDMK KTRGRLYLRPELLAKRPCVDIQEENNMKALAGVFFDRTELDRKE LTFTESTHVEIKNFSTEKLLQRIKEILPQY VSAFANTDGGYLFIGLNED EIIGFKAEMSDLDDLEREIEKSIRKMPVHHFCMEKKKINYSCKFLGVYDKGSLCG YVCALRVERFCCAVFAKEPDSWHVKDNRVMQLTRKEWIQFMVEAEPKFSSSYEEVISQIN TSLPAPHSWPLLEWQ RQRHHCPGLSGRITYTPENLCRKLFLQHEGLKQLICEEMDSVRKGSLIFSRSWSVDLGLQ ENH VLCDALLISQD SPPVLYTFHMVQDEEFKGYSTQTALTLKQKLAKIGGYTKKVCVMTKIFYLSPEGMTSCQY DLRSQVIYPESYYFT RRKYLLKALFKALKRLKSLRDQFSFAENLYQIIGIDCFQKNDKK FKSCRRLT (SEQ ID NO.: 5)

By "Schlafen 12 {SLFN12) polynucleotide" is meant any nucleic acid molecule, including DNA and RNA, encoding a SLFN12 polypeptide or fragment thereof. An exemplary SLFN12 nucleic acid sequence is provided at NCBI Ref: NM_018042.4:

1 tttgtaactt cacttcagcc tcccattgat cgctttctgc aaccattcag actgatctcg

61 ggctcctatt tcatttacat tgtgtgcaca ccaagtaacc agtgggaaaa ctttagaggg

121 tacttaaacc ccagaaaatt ctgaaaccgg gctcttgagc cgctatcctc gggcctgctc

181 ccaccctgtg gagtgcactt tcgttttcaa taaatctctg cttttgttgc ttcattcttt

241 ccttgctttg tttgtgtgtt tgtccagttc tttgttcaac acgccaagaa cctggacact

301 cttcactggt aacatatttt ggcaagccaa ccaggagaaa agaatttctg cttggacact

361 gcatagctgc tgggaaaatg aacatcagtg ttgatttgga aacgaattat gccgagttgg

421 ttctagatgt gggaagagtc actcttggag agaacagtag gaaaaaaatg aaggattgta

481 aactgagaaa aaagcagaat gaaagtgtct cacgagctat gtgtgctctg ctcaattctg

541 gagggggagt gatcaaggct gaaattgaga atgaagacta tagttataca aaagatggaa

601 taggactaga tttggaaaat tcttttagta acattctgtt atttgttcct gagtacttag

661 acttcatgca gaatggtaac tactttctga tttttgtgaa gtcatggagc ttgaacacct

721 ctggtctgcg gattaccacc ttgagctcca atttgtacaa aagagatata acatctgcaa

781 aagtcatgaa tgccactgct gcactggagt tcctcaaaga catgaaaaag actagaggga

841 gattgtattt aagaccagaa ttgctggcaa agaggccctg tgttgatata caagaagaaa

901 ataacatgaa ggccttggcc ggggtttttt ttgatagaac agaacttgat cggaaagaaa

961 aattgacctt tactgaatcc acacatgttg aaattaaaaa cttctcgaca gaaaagttgt

102.1 tacaacgaat taaagagatt ctccctcaat atgtttctgc atttgcaaat actgatggag

1081 gatatttgtt cattggttta aatgaagata aagaaataat tggctttaaa gcagagatga

1141 gtgacctcga tgacttagaa agagaaatcg aaaagtccat taggaagatg cctgtgcatc

1201 acttctgtat ggagaagaag aagataaatt attcatgcaa attccttgga gtatatgata

1261 aaggaagtct ttgtggatat gtctgtgcac tcagagtgga gcgcttctgc tgtgcagtgt

1321 ttgctaaaga gcctgattcc tggcatgtga aagataaccg tgtgatgcag ttgaccagga

1381 aggaatggat ccagttcatg gtggaggctg aaccaaaatt ttccagttca tatgaagagg

1441 tgatctctca aataaatacg tcattacctg ctccccacag ttggcctctt ttggaatggc

1501 aacggcagag acatcactgt ccagggctat caggaaggat aacgtatact ccagaaaacc

1561 tttgcagaaa actgttctta caacatgaag gacttaagca attaatatgt gaagaaatgg

1621 actctgtcag aaagggctca ctgatcttct ctaggagctg gtctgtggat ctgggcttgc

1681 aagagaacca caaagtcctc tgtgatgctc ttctgatttc ccaggacagt cctccagtcc

1741 tatacacctt ccacatggta caggatgagg agtttaaagg ctattctaca caaactgccc

1801 taaccttaaa gcagaagctg gcaaaaattg gtggttacac taaaaaagtg tgtgtcatga

1861 caaagatctt ctacttgagc cctgaaggca tgacaagctg ccagtatgat ttaaggtcgc

1921 aagtaattta ccctgaatcc tactatttta caagaaggaa atacttgctg aaagcccttt

1981 ttaaagcctt aaagagactc aagtctctga gagaccagtt ttcctttgca gaaaatctat

2041 accagataat cggtatagat tgctttcaga agaatgataa aaagatgttt aaatcttgtc

2101 gaaggctcac ctgatggaaa atggactggg ctactgagat atttttcatt atatatttga 2161 taacattctc taattctgtg aaaatatttc tttgaaaact ttgcaagtta agcaacttaa 2221 tgtgatgttg gataattggg ttttgtctat tttcacttct ccctaaataa tcttcacaga 2281 tattgtttga gggatattag gaaaattaat ttgttaactc gtctgtgcac agtattattt 2341 actctgtctg tagttcctga ataaattttc ttccatgctt gaactgggaa aattgcaaca 2401 cttttattct taatgacaac agtgaaaatc tcccagcata tacctagaaa acaattataa

2461 cttacaaaag attatccttg atgaaactca gaatttccac agtgggaatg aataagaagg 2521 caaaactcat (SEQ ID NO. : 6)

In some aspects, the compound is an isomer. "Isomers" are different compounds that have the same molecular formula. "Stereoisomers" are isomers that differ only in the way the atoms are arranged in space. As used herein, the term "isomer" includes any and all geometric isomers and stereoisomers. For example, "isomers" include geometric double bond cis- and trans-isomers, also termed E- and Z-isomers; R- and S-enantiomers; diastereomers, (d)-isomers and (l)-isomers, racemic mixtures thereof; and other mixtures thereof, as falling within the scope of this invention.

Geometric isomers can be represented by the symbol which denotes a bond that can be a single, double or triple bond as described herein. Provided herein are various geometric isomers and mixtures thereof resulting from the arrangement of substituents around a carbon-carbon double bond or arrangement of substituents around a carbocyclic ring. Substituents around a carbon-carbon double bond are designated as being in the "Z" or "E" configuration wherein the terms "Z" and "E" are used in accordance with IUPAC standards. Unless otherwise specified, structures depicting double bonds encompass both the "E" and "Z" isomers.

Substituents around a carbon-carbon double bond alternatively can be referred to as "cis" or "trans," where "cis" represents substituents on the same side of the double bond and "trans" represents substituents on opposite sides of the double bond. The arrangement of substituents around a carbocyclic ring can also be designated as "cis" or "trans." The term "cis" represents substituents on the same side of the plane of the ring, and the term "trans" represents substituents on opposite sides of the plane of the ring. Mixtures of compounds wherein the substituents are disposed on both the same and opposite sides of plane of the ring are designated "cis/trans."

The term "enantiomers" refers to a pair of stereoisomers that are non-superimposable mirror images of each other. An atom having an asymmetric set of substituents can give rise to an enantiomer. A mixture of a pair of enantiomers in any proportion can be known as a "racemic" mixture. The term "(±)" is used to designate a racemic mixture where appropriate. "Diastereoisomers" are stereoisomers that have at least two asymmetric atoms, but which are not mirror-images of each other. The absolute stereochemistry is specified according to the Cahn-Ingold-Prelog R-S system. When a compound is an enantiomer, the stereochemistry at each chiral carbon can be specified by either R or S. Resolved compounds whose absolute configuration is unknown can be designated (+) or (-) depending on the direction (dextro- or levorotatory) which they rotate plane polarized light at the wavelength of the sodium D line. Certain of the compounds described herein contain one or more asymmetric centers and can thus give rise to enantiomers, diastereomers, and other stereoisomeric forms that can be defined, in terms of absolute stereochemistry at each asymmetric atom, as (R)- or (S)-. The present chemical entities, pharmaceutical compositions and methods are meant to include all such possible isomers, including racemic mixtures, optically substantially pure forms and intermediate mixtures.

Optically active (R)- and (S)-isomers can be prepared, for example, using chiral synthons or chiral reagents, or resolved using conventional techniques. Enantiomers can be isolated from racemic mixtures by any method known to those skilled in the art, including chiral high pressure liquid chromatography (HPLC), the formation and crystallization of chiral salts, or prepared by asymmetric syntheses.

Optical isomers can be obtained by resolution of the racemic mixtures according to conventional processes, e.g., by formation of diastereoisomeric salts, by treatment with an optically active acid or base. Examples of appropriate acids are tartaric, diacetyltartaric, dibenzoyltartaric, ditoluoyltartaric, and camphorsulfonic acid. The separation of the mixture of diastereoisomers by crystallization followed by liberation of the optically active bases from these salts affords separation of the isomers. Another method involves synthesis of covalent diastereoisomeric molecules by reacting disclosed compounds with an optically pure acid in an activated form or an optically pure isocyanate. The synthesized diastereoisomers can be separated by conventional means such as chromatography, distillation, crystallization or sublimation, and then hydro lyzed to deliver the enantiomerically enriched compound. Optically active compounds can also be obtained by using active starting materials. In some embodiments, these isomers can be in the form of a free acid, a free base, an ester or a salt.

In certain embodiments, the compound of the invention can be a tautomer. As used herein, the term "tautomer" is a type of isomer that includes two or more interconvertible compounds resulting from at least one formal migration of a hydrogen atom and at least one change in valency (e.g., a single bond to a double bond, a triple bond to a single bond, or vice versa). "Tautomerization" includes prototropic or proton-shift tautomerization, which is considered a subset of acid-base chemistry. "Prototropic tautomerization" or "proton-shift tautomerization" involves the migration of a proton accompanied by changes in bond order. The exact ratio of the tautomers depends on several factors, including temperature, solvent, and pH. Where tautomerization is possible (e.g., in solution), a chemical equilibrium of tautomers can be reached. Tautomerizations (i.e., the reaction providing a tautomeric pair) can be catalyzed by acid or base, or can occur without the action or presence of an external agent. Exemplary tautomerizations include, but are not limited to, keto-to-enol; amide-to- imide; lactam-to-lactim; enamine-to-imine; and enamine-to-(a different) enamine tautomerizations. A specific example of keto-enol tautomerization is the interconversion of pentane-2,4-dione and 4- hydroxypent-3-en-2-one tautomers. Another example of tautomerization is phenol-keto

tautomerization. A specific example of phenol-keto tautomerization is the interconversion of pyridin- 4-ol and pyridin-4(lH)-one tautomers.

All chiral, diastereomeric, racemic, and geometric isomeric forms of a structure are intended, unless specific stereochemistry or isomeric form is specifically indicated. All processes used to prepare compounds of the present invention and intermediates made therein are considered to be part of the present invention. All tautomers of shown or described compounds are also considered to be part of the present invention.

By "agent" is meant any small molecule chemical compound, antibody, nucleic acid molecule, or polypeptide, or fragments thereof.

By "ameliorate" is meant decrease, suppress, attenuate, diminish, arrest, or stabilize the development or progression of a disease.

By "alteration" is meant a change (increase or decrease) in the expression levels or activity of a gene or polypeptide as detected by standard art known methods such as those described herein. As used herein, an alteration includes an about 10% change in expression levels, preferably an about 25% change, more preferably an about40% change, and most preferably an about 50% or greater change in expression levels. "

By "analog" is meant a molecule that is not identical, but has analogous functional or structural features. For example, a polypeptide analog retains the biological activity of a corresponding naturally-occurring polypeptide, while having certain biochemical modifications that enhance the analog's function relative to a naturally occurring polypeptide. Such biochemical modifications could increase the analog's protease resistance, membrane permeability, or half-life, without altering, for example, ligand binding. An analog may include an unnatural amino acid.

In this disclosure, "comprises," "comprising," "containing" and "having" and the like can have the meaning ascribed to them in U.S. Patent law and can mean " includes," "including," and the like; "consisting essentially of or "consists essentially" likewise has the meaning ascribed in U.S. Patent law and the term is open-ended, allowing for the presence of more than that which is recited so long as basic or novel characteristics of that which is recited is not changed by the presence of more than that which is recited, but excludes prior art embodiments.

"Detect" refers to identifying the presence, absence or amount of the analyte to be detected.

In particular embodiments, the analyte is a PDE3A or SLFN12 polypeptide.

By "disease" is meant any condition or disorder that damages or interferes with the normal function of a cell, tissue, or organ. Examples of diseases include melanoma, adenocarcinoma, lung cancer, cervical cancer, liver cancer and breast cancer.

By "effective amount" is meant the amount of a compound described herein required to ameliorate the symptoms of a disease relative to an untreated patient. The effective amount of active compound(s) used to practice the present invention for therapeutic treatment of a disease varies depending upon the manner of administration, the age, body weight, and general health of the subject. Ultimately, the attending physician or veterinarian will decide the appropriate amount and dosage regimen. Such amount is referred to as an "effective" amount. In one embodiment, the compound is DNMDP, zardaverine, or anagrelide.

The invention provides a number of targets that are useful for the development of highly specific drugs to treat or a disorder characterized by the methods delineated herein. In addition, the methods of the invention provide a facile means to identify therapies that are safe for use in subjects. In addition, the methods of the invention provide a route for analyzing virtually any number of compounds for effects on a disease described herein with high-volume throughput, high sensitivity, and low complexity.

By "fragment" is meant a portion of a polypeptide or nucleic acid molecule. This portion contains, preferably, at least about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, or about 90% of the entire length of the reference nucleic acid molecule or polypeptide. A fragment may contain about 10, about 20, about 30, about 40, about 50, about 60, about 70, about 80, about 90, about 100, about 200, about 300, about 400, about 500, about 600, about 700, about 800, about 900, or about 1000 nucleotides or amino acids.

"Hybridization" means hydrogen bonding, which may be Watson-Crick, Hoogsteen or reversed Hoogsteen hydrogen bonding, between complementary nucleobases. For example, adenine and thymine are complementary nucleobases that pair through the formation of hydrogen bonds.

By "marker" or "biomarker" is meant any protein or polynucleotide having an alteration in expression level or activity (e.g., at the protein or mRNA level) that is associated with a disease or disorder. In particular embodiments, a marker of the invention is PDE3A or SLFN12.

By "modulator" is meant any agent that binds to a polypeptide and alters a biological function or activity of the polypeptide. A modulator includes, without limitation, agents that reduce or eliminate a biological function or activity of a polypeptide (e.g., an "inhibitor"). For example, a modulator may inhibit a catalytic activity of a polypeptide. A modulator includes, without limitation, agents that increase or decrease binding of a polypeptide to another agent. For example, a modulator may promote binding of a polypeptide to another polypeptide. In some embodiments, a modulator of PDE3A polypeptide is DNMDP. In some other embodiments, the modulator of PDE3A polypeptide is anagrelide or zardaverine.

By "reference" is meant a standard or control condition.

Nucleic acid molecules useful in the methods of the invention include any nucleic acid molecule that encodes a polypeptide of the invention or a fragment thereof. Such nucleic acid molecules need not be 100% identical with an endogenous nucleic acid sequence, but will typically exhibit substantial identity. Polynucleotides having "substantial identity" to an endogenous sequence are typically capable of hybridizing with at least one strand of a double-stranded nucleic acid molecule. Nucleic acid molecules useful in the methods of the invention include any nucleic acid molecule that encodes a polypeptide of the invention or a fragment thereof. Such nucleic acid molecules need not be 100% identical with an endogenous nucleic acid sequence, but will typically exhibit substantial identity. Polynucleotides having "substantial identity" to an endogenous sequence are typically capable of hybridizing with at least one strand of a double-stranded nucleic acid molecule. By "hybridize" is meant pair to form a double-stranded molecule between complementary polynucleotide sequences (e.g., a gene described herein), or portions thereof, under various conditions of stringency. (See, e.g., Wahl, G. M. and S. L. Berger (1987) Methods Enzymol. 152:399; Kimmel, A. R. (1987) Methods Enzymol. 152:507).

For example, stringent salt concentration will ordinarily be less than about 750 mM NaCl and 75 mM trisodium citrate, preferably less than about 500 mM NaCl and 50 mM trisodium citrate, and more preferably less than about 250 mM NaCl and 25 mM trisodium citrate. Low stringency hybridization can be obtained in the absence of organic solvent, e.g., formamide, while high stringency hybridization can be obtained in the presence of at least about 35% formamide, and more preferably at least about 50% formamide. Stringent temperature conditions will ordinarily include temperatures of at least about 30° C, more preferably of at least abput 37° C, and most preferably of at least about 42° C. Varying additional parameters, such as hybridization time, the concentration of detergent, e.g., sodium dodecyl sulfate (SDS), and the inclusion or exclusion of carrier DNA, are well known to those skilled in the art. Various levels of stringency are accomplished by combining these various conditions as needed. In a preferred: embodiment, hybridization will occur at 30° C in 750 mM NaCl, 75 mM trisodium citrate, and 1% SDS. In a more preferred embodiment, hybridization will occur at 37° C in 500 mM NaCl, 50 mM trisodium citrate, 1% SDS, 35% formamide, and 100 μ§/τη1 denatured salmon sperm DNA (ssDNA). In a most preferred embodiment, hybridization will occur at 42° C in 250 mM NaCl, 25 mM trisodium citrate, 1% SDS, 50% formamide, and 200 μg/ml ssDNA. Useful variations on these conditions will be readily apparent to those skilled in the art.

For most applications, washing steps that follow hybridization will also vary in stringency. Wash stringency conditions can be defined by salt concentration and by temperature. As above, wash stringency can be increased by decreasing salt concentration or by increasing temperature. For example, stringent salt concentration for the wash steps will preferably be less than about 30 mM NaCl and 3 mM trisodium citrate, and most preferably less than about 15 mM NaCl and 1.5 mM trisodium citrate. Stringent temperature conditions for the wash steps will ordinarily include a temperature of at least about 25° C, more preferably of at least about 42° C, and even more preferably of at least about 68° C. In a preferred embodiment, wash steps will occur at 25° C in 30 mM NaCl, 3 mM trisodium citrate, and 0.1% SDS. In a more preferred embodiment, wash steps will occur at 42 C in 15 mM NaCl, 1.5 mM trisodium citrate, and 0.1% SDS. In a more preferred embodiment, wash steps will occur at 68° C in 15 mM NaCl, 1.5 mM trisodium citrate, and 0.1 % SDS. Additional variations on these conditions will be readily apparent to those skilled in the art. Hybridization techniques are well known to those skilled in the art and are described, for example, in Benton and Davis (Science 196: 180, 1977); Grunstein and Hogness (Proc. Natl. Acad. Sci, USA 72:3961 , 1975); Ausubel et al. (Current Protocols in Molecular Biology, Wiley Interscience, New York, 2001); Berger. and Kimmel (Guide to Molecular Cloning Techniques, 1987, Academic Press, New York); and Sambrook et al. Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, New York.

By "substantially identical" is meant a polypeptide or nucleic acid molecule exhibiting at least 50% identity to a reference amino acid sequence (for example, any one of the amino acid sequences described herein) or nucleic acid sequence (for example, any one of the nucleic acid sequences described herein). Preferably, such a sequence is at least 60%, more preferably 80% or 85%, and more preferably 90%, 95% or even 99% identical at the amino acid level or nucleic acid to the sequence used for comparison.

Sequence identity is typically measured using sequence analysis software (for example,

Sequence Analysis Software Package of the Genetics Computer Group, University of Wisconsin Biotechnology Center, 1710 University Avenue, Madison, Wis. 53705, BLAST, BESTFIT, GAP, or PILEUP/PRETTYBOX programs). Such software matches identical or similar sequences by assigning degrees of homology to various substitutions, deletions, and/or other modifications.

Conservative substitutions typically include substitutions within the following groups: glycine, alanine; valine, isoleucine, leucine; aspartic acid, glutamic acid, asparagine, glutamine; serine, threonine; lysine, arginine; and phenylalanine, tyrosine. In an exemplary approach to determining the degree of identity, a BLAST program may be used, with a probability score between e ^"3 and e ^"100 indicating a closely related sequence.

By "subject" is meant a mammal, including, but not limited to, a human or non-human mammal, such as a bovine, equine, canine, ovine, or feline.

Ranges provided herein are understood to be shorthand for all of the values within the range. For example, a range of 1 to 50 is understood to include any number, combination of numbers, or subrange from the group consisting 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, or 50.

As used herein, the terms "treat," treating," "treatment," and the like refer to reducing or ameliorating a disorder and/or symptoms associated therewith. It will be appreciated that, although not precluded, treating a disorder or condition does not require that the disorder, condition or symptoms associated therewith be completely eliminated. Unless specifically stated or obvious from context, as used herein, the term "or" is understood to be inclusive. Unless specifically stated or obvious from context, as used herein, the terms "a", "an", and "the" are understood to be singular or plural.

Unless specifically stated or obvious from context, as used herein, the term "about" is understood as within a range of normal tolerance in the art, for example within 2 standard deviations of the mean. About can be understood as within 10%, 9%, 8%, 7%>, 6%, 5%, 4%, 3%, 2%, 1 %, 0.5%, 0.1%), 0.05%), or 0.01%o of the stated value. Unless otherwise clear from context, all numerical values provided herein are modified by the term about.

The recitation of a listing of chemical groups in any definition of a variable herein includes definitions of that variable as any single group or combination of listed groups. The recitation of an embodiment for a variable or aspect herein includes that embodiment as any single embodiment or in combination with any other embodiments or portions thereof.

Any compositions or methods provided herein can be combined with one or more of any of the other compositions and methods provided herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Figures 1 A-1D show identification and characterization of 6-(4-(diethylamino)-3- nitrophenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one (DNMDP), a potent and selective cancer cell cytotoxic agent. Figure 1 A is a scatterplot of 1924 compounds showing mean survival of TP53 mutant NCI-H1734 cells, which is a non-small cell lung cancer cell line, and TP53 wild-type A549 cells, another lung cancer cell line, after 48 hours of treatment at concentrations of 10 μΜ. DNMDP is indicated with a large arrowhead. Other compounds that selectively killed NCI-H1734 cells are indicated with a small arrow. Positive control staurosporine is indicated with a long arrow. Figure 1 B is a linear graph showing a panel of cell lines that was treated with the indicated concentrations of DNMDP for 48 ho urs. Figure 1 C is a linear graph showing the HeLa cell line that was treated with indicated concentrations of the separated enantiomers of DNMDP for 48 hours. The (R)-enantiomer had a 500-fold lower EC ₅₀ compared to the (S)-enantiomer. Figure ID is a structure of (R)-DNMDP.

Figure 2 shows that DNMDP selectively killed NCI-H1734 and did not affect cell viability in A549. NCI -HI 734 and A549 cell lines were treated with indicated compounds and concentrations for 48 hours.

Figure 3 shows the synthesis scheme of (R)-6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5- dihydropyridazin-3(2H)-one (R)-DNMDP) and analogues. Reaction conditions are as follows: (a) Ac ₂ 0, (91 %); (b) 90% HN0 ₃ , H ₂ S0 ₄ , (19%); (c) NaOH, MeOH/H ₂ 0, (100%), then CH ₃ CHO, NaBH(OAc) ₃ , (7%); (d) (BrCH ₂ CH ₂ ) ₂ 0, K ₂ C0 ₃ , DMF, (46%); (e) CH ₃ CHO, NaBH ₃ CN, MeOH, (82%). Figures 4A-4C show super-critical fluid (SCF) chromatographs of 6-(4-(diethylamino)-3- nitrophenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one (DNMDP) (top to bottom: ES+, diode array, ES- traces). Figure 4A are three chromatographs showing Peak 1 (CRO separation); Figure 4B are three chromatographs showing Peak 2 (CRO separation); Figure 4C are three chromatographs showing synthesized (R)-DNMDP (5:95 ratio peaks 1 :2 by uv).

Figures 5A-5C show that Phosphodiesterase 3A (PDE3A) expression correlated with sensitivity to 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)-one

(DNMDP), but inhibition of PDE3A mediated cAMP hydrolysis did not correlate with cytotoxicity. Figure 5A is a scatterplot showing correlation between DNMDP sensitivity and expression of 18,988 genes in 766 genomically characterized cell lines. Cell lines were treated for 72 hours with concentrations ranging from 66.4 μΜ - 2 nM in 2-fold step dilutions. The Z-score for Pearson correlation between PDE3A expression and sensitivity to DNMDP is 8.5. Figure 5B is a scatterplot showing results from cell lines from panel A that were treated with 480 compounds. DNMDP showed the best correlation between PDE3A expression and sensitivity. Figure 5C is a scatterplot showing published PDE3 inhibitor IC ₅₀ values and EC ₅₀ values of HeLa cells treated with indicated compounds up to 10 μΜ for 48 hours. DNMDP IC ₅₀ concentration for PDE3A inhibition was determined in Figure 7B.

Figures 6A-6C show chemical structures of 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5- dihydropyridazin-3(2H)-one (DNMDP), siguazodan and levosimendan, respectively.

Figures 7A and 7B are graphs showing determination of Phosphodiesterase 3A (PDE3A) in vitro IC ₅₀ of 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)-one

(DNMDP). Figure 7A shows PDE3 A in vitro inhibition with indicated concentrations of positive control trequinsin (IC ₅₀ curve was performed by Caliper). Figure 7B shows PDE3A in vitro inhibition with indicated concentrations of DNMDP (IC ₅₀ curve was performed by Caliper).

Figures 8A and 8B are graphs showing that induction of cAMP signaling did not phenocopy cytotoxicity induced by 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)-one (DNMDP). Forskolin: FSK. Figure 8A shows cAMP concentrations that were measured 1 hour after treatment with indicated compounds and concentration in HeLa cells. Figure 8B shows viability of HeLa cells that were treated with indicated compounds and concentrations for 48 hours.

Figures 9A-9C show that non-lethal Phosphodiesterase 3 (PDE3) inhibitors rescued cell death induced by 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)-one (DNMDP) by competing for the binding of PDE3A. Figure 9A is a scatterplot showing viability of HeLa cells that were treated with 1600 bioactive compounds at a concentration of 20 μΜ in combination with 30 nM (EC70) of DNMDP for 48 hours. The viability was calculated as a percentage of the untreated DMSO control. Figure 9B is a linear graph showing viability of HeLa cells that were treated with DNMDP in combination with indicated concentrations of non-lethal PDE3 and pan-PDE inhibitors for 48 hours. Figure 9C shows a SDS-PAGE gel depicting the result of affinity purification performed on 200 μg of HeLa cell lysate using a DNMDP linker-analogue tethered to a solid phase with the same rescue characteristic as non-lethal PDE3 inhibitors. Indicated compounds were co- incubated with the linker-analogue. The affinity purified fraction was run on an SDS-PAGE gel and probed for PDE3A.

Figures 10A and 10B show the structure and rescue phenotype of linker-compound tert-butyl (R)-(2-(2-(2-(ethyl(4-(4-methyl-6-oxo-l ,4,5,6-tetrahydropyridazin-3-yl)phenyl)amino)ethoxy) ethoxy)ethyl)carbamate (DNMDP) -2L. Figure 1 OA shows the structure of DNMDP -2L. Figure 1 OB is a graph showing the viability of HeLa cells that were treated with indicated compounds and concentrations for 48 hours.

Figures 1 1 A-l 1C show that Phosphodiesterase 3A (PDE3A) was not essential in sensitive cell lines, but was required for relaying the cytotoxic signal. Figure- 1 1 A is a Western blot. HeLa cells were infected with Cas9 and indicated guide RNAs (sgRNA) against PDE3A. Western blots were probed for PDE3A at indicated time points. Figure 1 IB is a bar graph showing percent rescue of HeLa cells that were infected with indicated sgRNAs for two weeks and treated with 1 μΜ of 6-(4- (diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyridazin- 3(2H)-one (DNMDP) for 48 hours. Percent rescue was normalized to the Cas9-only control. Figure 11C is a plot showing viability of cells infected with indicated sgRNAs and treated with various concentrations of 6-(4-(diethylamino)- 3-nitrophenyl)-5-methyl-4,5-dihydropyridazin-3(2H)-one (DNMDP).

Figures 12A and 12B are a Western blot and a graph showing that reduction of

Phosphodiesterase 3A (PDE3A) protein level caused resistance to 6-(4-(diethylamino)-3-nitrophenyl)- 5-methyl-4,5-dihydropyridazin-3(2H)-one (DNMDP). In Figure 12A HeLa cells were treated with scrambled control siRNA or a combination of four different siRNAs targeting PDE3A. Cells were lysed at indicated time-points and immunoblotted for PDE3A and Actin. Figure 12B is a linear graph showing viability of HeLa cells that were treated with indicated concentrations of DNMDP analogue 3 for 48 hours.

Figures 13A-13C show that Phosphodiesterase 3A (PDE3A) immunoprecipitation in the presence of 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)-one (DNMDP) revealed novel SIRT7 and SLFN12 interaction. Figure 13A shows a schematic overview of the affinity enrichment followed by quantitative proteomics of PDE3A performed in HeLa cells. All cells were treated for four hours prior to lysis with 10 μΜ of indicated compounds. The presence of all compounds was maintained throughout the experiment including washing steps. Figure 13B is a scatterplot showing log ₂ ratios for proteins that were enriched in anti-PDE3A immuno precipitates in the DMSO treated HeLa cells compared to anti-PDE3A immuno precipitates in the presence of blocking peptide specific to the PDE3A antibody; each dot represents a protein. Figure 13C is a scatterplot showing Log ₂ ratios of changes of proteins bound to PDE3A in the presence of DNMDP versus trequinsin. Each dot represents the average of two replicates per condition for an individual protein. In all cases, the data plotted passed the Bland-Altman test with 95% confidence interval for reproducibility.

Figures 14A-14C show results of replicate PDE3A-protein interaction studies using PDE3A as bait under different conditions. Each scatterplot showed log ₂ ratios of two replicates for proteins that were enriched by PDE3A under different conditions over enrichment by PDE3A in the presence of blocking peptide. Each dot represents the log ₂ ratio for that particular protein, medium gray dots correspond to a Benjamini-Hochberg adjusted p value <0.01 , light gray dots represent proteins that fall outside of the Blandt-Altman test for reproducibility within a 95% confidence interval. In Figure 14A protein enrichment was accomplished by immunoprecipitation using anti-PDE3 A. In Figure 14B protein enrichment was accomplished by immunoprecipitation using anti-PDE3A in the presence of DNMDP. In Figure 14C protein enrichment was accomplished by immunoprecipitation using anti- PDE3A in the presence of trequinsin.

Figures 15A-15E show that cell lines with dual expression of SLFN12 and PDE3A were significantly enriched for DNMDP -sensitive cell lines. Figure 15A is a scatterplot showing mRNA robust multichip average (RMA) expression values for PDE3A and SLFN12 from the Cancer Cell Line Encyclopedia (CCLE) database (a detailed genetic characterization of a large panel of human cancer cell lines;) with sensitive cell lines indicated (Barretina et al., Nature 483, 603-607, 2012). 21 sensitive cell lines were binned in three groups of 7 based on area under the curve (AUC) rank. Figure 15B is a bar graph showing results of a Fisher's exact test on DNMDP sensitivity of cell lines with high expression of both SLFN12 and PDE3A (RMA Log2 > 5) compared to other cell lines. The top half of the bar on the right indicates melanoma cell lines. Figure 15C is a scatterplot showing mRNA RPKM+1 expression values for PDE3A and SLFN12 from RNA sequencing data. Figure 15D is a bar graph showing qPCR expression changes of SLFN12 in HeLa cells transduced with shSLFN12 normalized to GAPDH. Figure 15E is a plot showing viability of HeLa cells transduced with indicated shRNA reagents and treated with indicated concentrations of DNMDP for 72 hours.

Figures 16A and 16B are scatter plots showing that SLFN12 expression was amongst the top genes correlating with DNMDP sensitivity. Figure 16A shows the correlation between DNMDP sensitivity and expression of 18,988 genes in 766 genomically characterized cell lines. Cell lines were treated for 72 hours with concentrations ranging from 66.4 μΜ - 2 nM in 2-fold step dilutions. Figure 16B is a scatterplot showing a correlation between DNMDP sensitivity and expression of 18,988 genes in 766 genomically characterized cell lines. Expression levels were corrected for PDE3A expression as described earlier (Kim et al., Genetica 131, 151-156, 2007). Cell lines were treated for 72 hours with concentrations ranging from 66.4 μΜ— 2 nM in 2-fold step dilutions.

Figures 17A-7B show that DNMDP induces apoptosis in HeLa cells. Figure 17A is a plot showing viability of HeLa cells treated for 48 hours with indicated concentrations of DNMDP. Caspase-Glo represents Caspase 3/7 activity indicating induction of apoptosis. CellTiter-Glo reflects viability. Figure 17B is an immunoblot. HeLa cells were treated for 36 hours with indicated compounds and concentrations. HeLa cells were harvested and immunoblotted for PARP-cleavage products, indicative of apoptosis.

Figure 18 is a scatterplot of PDE3A mRNA expression and sensitivity to DNMDP of 766 cancer cell lines.

Figure 19 is an immunoblot showing that DNMDP induces interaction between PDE3A and SIRT7 and SLFN12 in HeLa cells. HeLa cells were transfected with indicated plasmids and treated with indicated compounds with a final concentration of 10 μΜ for four hours. Endogenous PDE3 A was immunoprecipitated and immunoblotted for V5 to identify novel interaction with SIRT7 and

SLFN12 (upper two panels). Immunoprecipitate input was immunoblotted for PDE3A and V5 (lower two panels). V5-SLFN12 was undetectable in whole cell lysate.

Figure 20 is an immunoblot showing confirmation of mass spectrometric results herein using affinity reagents. Figure 20 shows that DNMDP and (weakly) anagrelide, but not trequinsin, induced PDE3A and SFLN12 complex formation.

Figure 21 is a set of tables showing that SLFN12 is lost in cells that have acquired resistance to DNMDP.

Figure 22 is a plot showing sensitization of a DNMDP -resistant cell line by expression of SLFN12 or expression of SFLN12 and PDE3A.

Figure 23 is a scatter plot showing sensitivity of Leiomyosarcomas (LMS) to PDE3A modulation based on SLFN12 expression level.

Table 1 shows sensitivity data of 766 cancer cell lines treated with DNMDP. Cell lines were treated for 72 hours with concentrations ranging from 66.4 μΜ - 2 nM in 2-fold step dilutions.

Table 2 shows results from panel of 19 phosphodiesterase inhibition reactions performed by Caliper. DNMDP concentration was 100 nM.

Table 3 shows RPKM values of SLFN12 and PDE3A expression in multiple healthy tissue types.

Table 4 showing Leiomyosarcoma sensitivity to DNMDP

Table 5 shows binding of DNMDP to PDE3A(677-1141).

Compositions and articles defined by the invention were isolated or otherwise manufactured in connection with the examples provided below. Other features and advantages of the invention will be apparent from the detailed description, and from the claims.

DETAILED DESCRIPTION

As described below, the present invention features improved methods of identifying patients having cancer (e.g., melanoma, endometrium, lung, hematopoetic / lymphoid, ovarian, cervical, soft- tissue sarcoma, leiomyosarcoma, urinary tract, pancreas, thyroid, kidney, glioblastoma, or breast cancer)) that is sensitive to treatment with a phosphodiesterase 3 A (PDE3A) modulator by detecting co-expression of PDE3A and Schlafen 12 (SLFN12) polypeptides or polynucleotides in a cancer cell derived from such patients. The invention is based at least in part on the discovery that sensitivity to phosphodiesterase 3A modulators, such as 6-(4-(diethylamino)-3-nitrophenyl)~5-methyl-4,5- dihydropyridazin-3(2H)-one, or DNMDP, in 766 cancer cell lines correlated with expression of the phosphodiesterase 3A gene, PDE3A. Like DNMDP, a subset of PDE3A inhibitors kill selected cancer cells while others do not; these cell-sparing PDE3A inhibitors instead block DNMDP induced cytotoxicity. Furthermore, PDE3A depletion leads to DNMDP resistance. DNMDP binding to PDE3A promotes an interaction between PDE3A and Sirfuin 7 (SIRT7) and Schlafen 12 (SLFN12), suggesting a neomorphic activity, and SLFN12 and PDE3A co-expression correlated with DNMDP sensitivity. These results indicate that PDE3 A modulators are promising cancer therapeutic agents and demonstrate the power of chemogenomics in small-molecule discovery and target-identification.

Accordingly, the invention provides methods of selecting a subject as having a cancer that responds to a PDE3A modulator, where the selection method involves detecting co-expression of

PDE3A and Schlafen 12 (SLFN12) polypeptides or polynucleotides, in a cancer cell derived from such subjects.

PDE3A Modulator

The identification of PDE3A modulators was made in connection with a phenotypic screen designed to identify cytotoxic small molecules in a mutant tp53 background. A chemogenomics approach complements target-driven drug development programs, which consists of extensive in vitro and in vivo target validation, and can also be referred to as reverse chemogenomics (Zheng et al., Curr Issues Mol Biol 4, 33-43, 2002). Many U.S. Food and Drug Administration (FDA) -approved targeted therapies have been developed this way, among them small-molecule kinase inhibitors that target oncogenic somatic driver mutations (Moffat et al, Nat Rev Drug Discov 13, 588—602, 2014). However, the discovery and development of targeted therapies is often hampered by limitations in knowledge of the biological function of the target, its mechanism of action, and the available chemical matter to selectively inhibit the target.

Phenotypic screening can discover novel targets for cancer therapy whose specific molecular mechanism is often elucidated by future studies (Swinney et al., Nat Rev Drug Discov 10, 507-519, 201 1). In recent years, two classes of anti-cancer drugs found by unbiased phenotypic screening efforts have been approved by the FDA. Lenalidomide and pomalidomide were found to be modulators of an E3-ligase that alter the affinity of its target, leading to degradation of lineage specific transcription factors (Kronke et al., Science 343, 301-305, 2014; Lu et al., Science 343, SOS- SO , 2014), whereas romidepsin and vorinostat were later identified as histone deacetylase (HDAC) inhibitors (Moffat et al., Nat Rev Drug Discov 13, 588-602, 2014; Nakajima et al., Exp. Cell Res. 241 , 126-133, 1998, Marks et al., Nat Biotechnol 25, 84-90, 2007).

Tumor suppressor alterations are suitable targets for phenotypic screening as they are not directly targetable with small molecules, although synthetic lethal approaches such as olaparib treatment of BRCA1/BRCA2 mutant cancers have proven to be effective. According to current knowledge, the tp53 tumor suppressor gene is the most frequently mutated across human cancer, with somatic mutations detected in 36% of 4742 cancers subjected to whole exome sequencing. Despite many attempts, no compounds that selectively kill tp53 mutant cells have been identified.

A phenotypic screen developed to identify small molecules causing synthetic lethality in tp53 mutant cancer cells enabled the serendipitous discovery of a class of cancer-selective cytotoxic agents which act as modulators of phosphodiesterase 3A (PDE3A), as described herein below. Cyclic nucleotide phosphodiesterases catalyze the hydrolysis of second messenger molecules cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), and are important in many physiological processes. Several phosphodiesterase inhibitors have been approved for clinical treatment, including PDE3 inhibitors milrinone, cilostazol, and levosimendan for cardiovascular indications and inhibition of platelet coagulation, as well as the PDE3 inhibitor anagrelide for thrombocythemia. PDE5 inhibitors, e.g. vardenafil, are used for smooth muscle disorders including erectile dysfunction and pulmonary arterial hypertension, and the PDE4 inhibitor rofiumilast reduces exacerbations from chronic obstructive pulmonary disease (COPD).

Phosphodiesterase inhibitors act by direct inhibition of their targets or by allosteric modulation; for example, structural analysis of PDE4 has led to the design of PDE4D and PDE4B allosteric modulators (Burgin et al., Nat Biotechnol 28, 63-70, 2010; Gurney et al., Neurotherapeutics 12, 49-56, 2015). The data provided herein below indicates that the cancer cytotoxic

phosphodiesterase modulator DNMDP likely acts through a similar allosteric mechanism.

Accordingly, the invention provides methods for identifying subjects that have a malignancy that is likely to respond to PDE3A modulator treatment based on the level of PDE3A and SLFN12 expression in a subject biological sample comprising a cancer cell. In some embodiments, the PDE3A modulator is DNMDP. In some other embodiments, the PDE3A modulator is anagrelide or zardaverine.

Compound Forms and Salts

The compounds of the present invention include the compounds themselves, as well as their salts and their prodrugs, if applicable. A salt, for example, can be formed between an anion and a positively charged substituent (e.g., amino) on a compound described herein. Suitable anions include chloride, bromide, iodide, sulfate, nitrate, phosphate, citrate, methanesulfonate, trifluoroacetate, and acetate. Likewise, a salt can also be formed between a cation and a negatively charged substituent (e.g., carboxylate) on a compound described herein. Suitable cations include sodium ion, potassium ion, magnesium ion, calcium ion, and an ammonium cation such as tetramethylammonium ion. Examples of prodrugs include C ₆ alkyl esters of carboxylic acid groups, which, upon administration to a subject, are capable of providing active compounds.

Pharmaceutically acceptable salts of the compounds of the present disclosure include those derived from pharmaceutically acceptable inorganic and organic acids and bases. As used herein, the term "pharmaceutically acceptable salt" refers to a salt formed by the addition of a pharmaceutically acceptable acid or base to a compound disclosed herein. As used herein, the phrase "pharmaceutically acceptable" refers to a substance that is acceptable for use in pharmaceutical applications from a toxicological perspective and does not adversely interact with the active ingredient.

Examples of suitable acid salts include acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptanoate, glycolate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, palmoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, salicylate, succinate, sulfate, tartrate, thiocyanate, tosylate and undecanoate. Other acids, such as oxalic, while not in themselves pharmaceutically acceptable, may be employed in the preparation of salts useful as intermediates in obtaining the compounds of the present invention and their pharmaceutically acceptable acid addition salts. Salts derived from appropriate bases include alkali metal (e.g., sodium), alkaline earth metal (e.g., magnesium), ammonium and N-(alkyl) ₄ ⁺ salts. The present invention also envisions the quaternization of any basic nitrogen-containing groups of the compounds disclosed herein. Water or oil-soluble or dispersible products may be obtained by such quaternization. Salt forms of the compounds of any of the formulae herein can be amino acid salts of carboxyl groups (e.g., L-arginine, -lysine, -histidine salts).

Lists of suitable salts are found in Remington's Pharmaceutical Sciences, 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418; Journal of Pharmaceutical Science, 66, 2 (1977); and "Pharmaceutical Salts: Properties, Selection, and Use A Handbook; Wermuth, C. G. and Stahl, P. H. (eds.) Verlag Helvetica Chimica Acta, Zurich, 2002 [ISBN 3 -906390-26-8] each of which is incorporated herein by reference in their entireties.

The neutral forms of the compounds may be regenerated by contacting the salt with a base or acid and isolating the parent compound in the conventional manner. The parent form of the compound differs from the various salt forms in certain physical properties, such as solubility in polar solvents, but otherwise the salts are equivalent to the parent form of the compound for the purposes of the present invention.

In addition to salt forms, the present invention provides compounds which are in a prodrug form. Prodrugs of the compounds described herein are those compounds that undergo chemical changes under physiological conditions to provide the compounds of the present invention.

Additionally, prodrugs can be converted to the compounds of the present invention by chemical or biochemical methods in an ex vivo environment. For example, prodrugs can be slowly converted to the compounds of the present invention when placed in a transdermal patch reservoir with a suitable enzyme or chemical reagent. Prodrugs are often useful because, in some situations, they may be easier to administer than the parent drug. They may, for instance, be more bioavailable by oral

administration than the parent drug. The prodrug may also have improved solubility in

pharmacological compositions over the parent drug. A wide variety of prodrug derivatives are known in the art, such as those that rely on hydrolytic cleavage or oxidative activation of the prodrug. An example, without limitation, of a prodrug would be a compound of the present invention which is administered as an ester (the "prodrug"), but then is metabolically hydrolyzed to the carboxylic acid, the active entity. Additional examples include peptidyl derivatives of a compound of the present invention.

The present invention also includes various hydrate and solvate forms of the compounds.

The compounds of the present invention may also contain unnatural proportions of atomic isotopes at one or more of the atoms that constitute such compounds. For example, the compounds may be radiolabeled with radioactive isotopes, such as for example tritium ( ³ H), iodine- 125 ( ¹²⁵ I) or carbon- 14 ( ¹⁴ C). All isotopic variations of the compounds of the present invention, whether radioactive or not, are intended to be encompassed within the scope of the present invention.

Diagnostics

The present invention features diagnostic assays for the characterization of cancer. In one embodiment, levels of PDE3A and/or Schlafen 12 (SLFN12) polynucleotides or polypeptides are measured in a subj ect sample and used as an indicator of cancer that is responsive to treatment with a PDE3A modulator. Levels of PDE3A and/or Schlafen 12 polynucleotides may be measured by standard methods, such as quantitative PCR, Northern Blot, microarray, mass spectrometry, and in situ hybridization. Standard methods may be used to measure levels of PDE3A and/or Schlafen 12, polypeptides in a biological sample derived from a tumor. Such methods include immunoassay, ELISA, western blotting using an antibody that binds PDE3A and/or Schlafen 12 and

radioimmunoassay. Elevated levels of PDE3A and Schlafen 12 polynucleotides or polypeptides relative to a reference are considered a positive indicator of cancer that is responsive to treatment with a PDE3A modulator. Types of biological samples In characterizing the responsiveness of a malignancy in a subject to PDE3A modulator treatment, the level of PDE3A and/or SLFN12 expression is measured in different types of biologic samples. In one embodiment, the biologic sample is a tumor sample.

PDE3A and/or SLFN12 expression is higher in a sample obtained from a subject that is responsive to PDE3A modulator treatment than the level of expression in a non-responsive subject. In another embodiment, PDE3A and/or SLFN12 is at least about 5, 10, 20, or 30-fold higher in a subject with a malignancy than in a healthy control. Fold change values are determined using any method known in the art. In one embodiment, change is determined by calculating the difference in expression of PDE3A and/or SLFN12 in a cancer cell vs the level present in a non-responsive cancer cell or the level present in a corresponding healthy control cell.

Selection of a treatment method

As reported herein below, subjects suffering from a malignancy may be tested for PDE3A and/or SLFN12 expression in the course of selecting a treatment method. Patients characterized as having increased PDE3A and/or SLFN12 relative to a reference level are identified as responsive to PDE3A modulator treatment.

Kits

The invention provides kits for characterizing the responsiveness or resistance of a subject to PDE3A modulator treatment.

Also provided herein are kits that can include a therapeutic composition containing an effective amount of a PDE3A modulator in, e.g., unit dosage form.

In one embodiment, a diagnostic kit of the invention provides a reagent for measuring relative expression of PDE3A and SLFN12. Such reagents include capture molecules (e.g., antibodies that recognize PDE3A and SLFN12 polypeptides or nucleic acid probes that hybridize with PDE3A and SLFN12 polynucleotides).

In some embodiments, the kit comprises a sterile container which includes a therapeutic or diagnostic composition; such containers can be boxes, ampoules, bottles, vials, tubes, bags, pouches, blister-packs, or other suitable container forms known in the art. Such containers can be made of plastic, glass, laminated paper, metal foil, or other materials suitable for holding medicaments.

In one embodiment, a kit of the invention comprises reagents for measuring PDE3 A and/or SLFN12 levels. If desired, the kit further comprises instructions for measuring PDE3A and/or SLFN12 and/or instructions for administering the PDE3A modulator to a subject having a malignancy, e.g., a malignancy selected as responsive to PDE3A modulator treatment. In particular embodiments, the instructions include at least one of the following: description of the therapeutic agent; dosage schedule and administration for treatment or prevention of malignancy or symptoms thereof; precautions; warnings; indications; counter-indications; over dosage information; adverse reactions; animal pharmacology; clinical studies; and/or references. The instructions may be printed directly on the container (when present), or as a label applied to the container, or as a separate sheet, pamphlet, card, or folder supplied in or with the container.

The practice of the present invention employs, unless otherwise indicated, conventional techniques of molecular biology (including recombinant techniques), microbiology, cell biology, biochemistry and immunology, which are well within the purview of the skilled artisan. Such techniques are explained fully in the literature, such as, "Molecular Cloning: A Laboratory Manual", second edition (Sambrook, 1989); "Oligonucleotide Synthesis" (Gait, 1984); "Animal Cell Culture" (Freshney, 1987); "Methods in Enzymology" "Handbook of Experimental Immunology" (Weir,

1996); "Gene Transfer Vectors for Mammalian Cells" (Miller and Calos, 1987); "Current Protocols in Molecular Biology" (Ausubel, 1987); "PCR: The Polymerase Chain Reaction", (Mullis, 1994); "Current Protocols in Immunology" (Coligan, 1991). These techniques are applicable to the production of the polynucleotides and polypeptides of the invention, and, as such, may be considered in making and practicing the invention. Particularly useful techniques for particular embodiments will be discussed in the sections that follow.

The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use the assay, screening, and therapeutic methods of the invention, and are not intended to limit the scope of the invention.

EXAMPLES

Example 1. Identification of a cell-selective cytotoxic small molecule

To identify anti-cancer compounds with cell-selective cytotoxic activity, an unbiased chemical

screen was performed in two lung adenocarcinoma cell lines, A549 and NCI-H1734, both of which harbor oncogenic KRAS mutations and truncating STK11 mutations, and which were TP 53 wild type and mutant (R273L), respectively. 1 ,924 compounds were screened from the Molecular Libraries Small-Molecule Repository validation set in the A549 and NCI-H1734 cell lines at a single concentration of 10 μΜ in 384-well format in duplicate. As a proxy for cellular viability, ATP content was measured after 48 hours of compound treatment.

Three compounds showed a selective reduction in cell viability for the NCI-HI 734 cell line compared to the A549 cell line, with an approximately 50% reduction in the NCI -HI 734 cell line, which is > 4 median absolute deviations from the median in the negative direction, compared to a minimal change of < 1 median absolute deviations from the median in the A549 cell line (Figure 1 A). Retesting the three compounds in a dose-response analysis validated that one compound, 6-(4- (diethylamino)-3-nitrophenyl)-5-methyl-4,5-dm^ or DNMDP, was specifically toxic to the NCI-H1734 cell line (Figure 2).

Testing of additional cell lines with DNMDP showed clear cell-selective cytotoxicity, with an EC ₅₀ between 10 and 100 nM for two additional lung adenocarcinoma cell lines, NCI-H1563 and NCI-H2122, and for HeLa cervical carcinoma cells, but an EC ₅₀ greater than 1 μΜ for A549, MCF7, and PC3 cells (Figure IB; Figure I C). Caspase activity was detected by a caspase-sensitive luciferase assay and by poly ADP ribose polymerase (PARP) cleavage in HeLa cells upon DNMDP treatment, indicating that sensitive cells undergo apoptosis after DNMDP exposure (Figures 17A-17B). To characterize cellular sensitivity to DNMDP further, 766 genomically characterized cancer cell lines were screened for DMNDP sensitivity at concentrations ranging from 66.4 μΜ to 2 nM in 2-fold dilution steps for 72 hours. From these cell lines, 22 cell lines were categorized as sensitive with a robust Z-score lower than -4, which represented multiple lineages including multiple melanoma cell lines, amongst others (Table 1).

Next, the DNMDP enantiomers were separated by chiral super-critical fluid (SCF) chromatography. One enantiomer was 500-fold more potent in HeLa cells than the other (Figures I C and D). The (R)-enantiomer was synthesized from commercially available starting materials (Figure 3). This synthesized enantiomer had similar activity to the more potent separated material and was identical by chiral SCF chromatography, confirming stereochemistry of the active enantiomer (Figures 4A-4C). Two (R)-des-nitro analogues of DNMDP were synthesized, both of which tested similarly to (R)-DNMDP (Figure 3). Figures 4A-4C show super-critical fluid (SCF) chromato graphs of 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)-one (DNMDP) (top to bottom: ES+, diode array, ES- traces). Figure 4A shows Peak 1 (CRO separation); Figure 4B shows Peak 2 (CRO separation); and Figure 4C shows synthesized (R)-DNMDP (5 :95 ratio peaks 1 :2 by uv).

Table 1 : Sensitivity data of 766 cancer cell lines treated with DNMDP

DNMDP

Lineage

Cell line AUC Robust Z-score

COV318 OVARY 0.095838 -6.863450362

IGR37 SKIN 0.41 146 -6.532158389

JHUEM1 ENDOMETRIUM 0.53468 -6.402820773

HAEMATOPOIETIC AND

HEL LYMPHOID TISSUE 0.57955 -6.355723071

CORL51 LUNG 0.59436 -6.340177786

HAEMATOPOIETIC AND

HEL9217 LYMPHOID TISSUE 0.75005 -6.176758102

NCIH1563 LUNG 1.0887 -5.821294837

SKMEL3 SKIN 1.2215 -5.681901594

NCIH2122 LUNG 1.3 105 -5.58848293 RVH421 SKIN 1.4556 -5.436179018

HAEMATOPOIETIC AND

HUT78 LYMPHOID TISSUE 1.5307 -5.35735046 DKMG CENTRAL NERVOUS SYSTEM 1.7217 -5.156867709 GB1 CENTRAL NERVOUS SYSTEM 1.8269 -5.046444748

G292CLONEA 141 B1 BONE 1.9664 -4.900018865

HMCB SKIN 1.9762 -4.889732315

A2058 SKIN 2.0833 -4.7773 15024

NCIH1734 LUNG 2.2179 -4.636032415

NCIH196 LUNG 2.5263 -4.312320999

LI7 LIVER 2.5414 -4.296471315

JHOM1 OVARY 2.7006 -4.129367368 COL0741 SKIN 2.7231 -4.10575029 HS578T BREAST 2.8012 -4.023772788 K029AX SKIN 2.9362 -3.88207032

HAEMATOPOIETIC AND

MONOMAC1 LYMPHOID TISSUE 2.9692 -3.847431939,

HT1 197 URINARY TRACT 3.0929 -3.717590492

NCIH520 LUNG 3.1351 -3.67329535

CAL78 BONE 3.171 1 -3.635508025

NCIH647 LUNG 3.2187 -3.585544785

CGTHW1 THYROID 3.4296 -3.36417404

NCIH1666 LUNG 3.6097 -3.175132451

L33 PANCREAS 3.625 -3.159072838

UACC62 SKIN 3.91 16 -2.858243747

CAS 1 CENTRAL NERVOUS SYSTEM 3.9993 -2.7661 89625

CAL51 BREAST 4.0017 -2.76367047

OSRC2 KIDNEY 4.326 -2.423269652

X8505C THYROID 4.3418 -2.406685215

SH4 SKIN 4.3672 -2.380024158

NCIH1395 LUNG 4.4473 -2.29594736

SNU503 LARGE INTESTINE 4.5692 -2.16799528

HS729 SOFT TISSUE 4.6518 -2.081294362

SW579 THYROID 4.697 -2.033850277

YH13 CENTRAL NERVOUS SYSTEM 4.7007 -2.029966579

DBTRG05MG CENTRAL NERVOUS SYSTEM 4.7415 -1.987140944

HAEMATOPOIETIC AND

SEM LYMPHOID TISSUE 4.7433 -1.985251578

HS852T SKIN 4.751 1 - 1.977064324

SNU449 LIVER 4.752 -1.9761 19641

NCIH2286 LUNG 4.7782 -1.948618866

JHOS2 OVARY 4.8254 -1.899075485

UPPER AEROD IGESTIVE

BICR31 TRACT 4.8356 -1.888369076 IGR1 SKIN 4.8613 -1.861393125 JHUEM3 ENDOMETRIUM 4.93 -1.789282313

SNU387 LIVER 4.9639 -1.753699249

UMUC1 URINARY TRACT 4.9933 -1.7228396

X8305C THYROID 5.0004 -1.7153871

NCIH1915 LUNG 5.0031 -1.712553051

HAEMATOPOIETIC AND

P31FUJ LYMPHOID TISSUE 5.0106 -1.704680691 COL0678 LARGE INTESTINE 5.0245 -1.690090585

HAEMATOPOIETIC AND

EOL1 LYMPHOID TISSUE 5.0478 -1.665633789

KNS42 CENTRAL NERVOUS SYSTEM 5.0791 -1.632779809

SW 1783 CENTRAL NERVOUS SYSTEM 5.1 161 -1.593942837

HS940T SKIN 5.1573 -1.550697343

SNU685 ENDOMETRIUM 5.206 -1.499579489

BCPAP THYROID 5.2336 -1.470609207

COL0829 SKIN 5.2432 -1.460532587

DM3 PLEURA 5.2635 -1.439224734

OCUM1 STOMACH 5.2843 -1.417392058

M059K CENTRAL NERVOUS SYSTEM 5.3059 -1.394719663

MG63 BONE 5.3943 -1.301930788

NCIH2172 LUNG 5.4245 -1.270231421

CAOV3 OVARY 5.4646 -1.228140539

HAEMATOPOIETIC AND

PEER LYMPHOID TISSUE 5.4754 -1.216804342

HS839T SKIN 5.5232 -1.166631 172

CORL105 LUNG 5.5442 -1.144588566

SNU5 STOMACH 5.5498 -1 .138710537

MFE296 ENDOMETRIUM 5.5618 -1.1261 14762

NCIH854 LUNG 5.576 -1.1 1 1209762

NCIH146 LUNG 5.5773 -1.10984522

NCIH2081 LUNG 5.581 1 -1.105856558

COV644 OVARY 5.5849 -1 .101867896

VCAP PROSTATE 5.5863 -1.100398388

UPPER AEROD IGESTIVE

BICR18 TRACT 5.6 -1.086018212

RH18 SOFT TISSUE 5.6283 -1.056313176

KPNYN AUTONOMIC GANGLIA 5.6717 -1.010758457

KPNSI9S AUTONOMIC GANGLIA 5.6827 -0.99921233

SKCOl LARGE INTESTINE 5.688 -0.993649196

HAEMATOPOIETIC AND

MV41 1 LYMPHOID TISSUE 5.6905 -0.991025076 COV362 OVARY 5.6913 -0.990185358

HAEMATOPOIETIC AND

NC02 LYMPHOID TISSUE 5.7088 -0.971816519 JHH4 LIVER 5.71 -0.970556942 NCIH2141 LUNG 5.7218 -0.958171096 LXF289 LUNG 5.734 -0.945365392

MEWO SKIN 5.738 -0.941 1668

TE125T SOFT TISSUE 5.744 -0.934868913

SNU869 BILIARY TRACT 5.7543 -0.924057539

LNC APCL ONEFGC PROSTATE 5.7557 -0.922588032

NCIH2009 LUNG 5.7594 -0.91 8704335

SKNBE2 AUTONOMIC GANGLIA 5.7717 -0.905793666

IALM LUNG 5.775 -0.902329827

DU145 PROSTATE 5.7825 -0.894457468

HCC1419 BREAST 5.7835 -0.89340782

HAEMATOPOIETIC AND

NALM6 LYMPHOID TISSUE 5.7872 -0.889524123

UPPER AERODIGESTIVE

PECAPJ15 TRACT 5.789 -0.887634757

LU99 LUNG 5.8016 -0.874409193

HAEMATOPOIETIC AND

LAMA 84 LYMPHOID TISSUE 5.8201 -0.854990707

ONCODG1 OVARY 5.8296 -0.845019051

HS888T BONE 5.8353 -0.839036058

SKNSH AUTONOMIC GANGLIA 5.8424 -0.831583558

TUETR14TKB KIDNEY 5.8451 -0.828749509

HAEMATOPOIETIC AND

PF382 LYMPHOID TISSUE 5.8519 -0.82161 1903

HAEMATOPOIETIC AND

ALLSIL LYMPHOID TISSUE 5.8724 -0.800094121

HAEMATOPOIETIC AND

KMS34 LYMPHOID TISSUE 5.8799 -0.792221762

UPPER AERODIGESTIVE

BICR6 TRACT 5.8837 -0.788233099

HAEMATOPOIETIC AND

GRANTA519 LYMPHOID TISSUE 5.8937 -0.77773662

HAEMATOPOIETIC AND

OCIAML2 LYMPHOID TISSUE 5.8945 -0.776896902

SUIT2 PANCREAS 5.8956 -0.775742289

BT549 BREAST 5.9226 -0.747401796

HAEMATOPOIETIC AND

KMS28BM LYMPHOID TISSUE 5.9369 -0.732391831

HCC1428 BREAST 5.9402 -0.728927992

HCC1500 BREAST 5.9451 -0.72378471 8

A549 LUNG 5.9509 -0.71769676

HAEMATOPOIETIC AND

KCL22 LYMPHOID TISSUE 5.9598 -0.708354893

COL0679 SKIN 5.9634 -0.704576161

SKMEL5 SKIN 5.9639 -0.704051337

HCC1395 BREAST 5.9716 -0.695969048

NCIH1435 LUNG 5.9756 -0.691770456

LOUNH91 LUNG 5.9793 -0.687886759

HAEMATOPOIETIC AND

RPMI8402 LYMPHOID TISSUE 5.9827 -0.684317956

COL0668 LUNG 5.9969 -0.669412956 SKLU1 LUNG 6.0109 -0.654717885

HAEMATOPOIETIC AND

KMS12BM LYMPHOID TISSUE 6.0135 -0.6519888 SNU1272 KIDNEY 6.0226 -0.642437004

HAEMATOPOIETIC AND

MOLM6 LYMPHOID TISSUE 6.0447 -0.619239786 EPLC272H LUNG 6.0469 -0.61693056

UPPER AERODIGESTIVE

SCC4 TRACT 6.0502 -0.613466722 LMSU STOMACH 6.0528 -0.610737638

HAEMATOPOIETIC AND

KMS20 LYMPHOID TISSUE 6.0542 -0.60926813

G402 SOFT TISSUE 6.0606 -0.602550384

KYSE410 OESOPHAGUS 6.0741 -0.588380137

HAEMATOPOIETIC AND

L540 LYMPHOID TISSUE 6.0807 -0.581452461

HAEMATOPOIETIC AND

MOLT13 LYMPHOID TISSUE 6.084 -0.577988623

HAEMATOPOIETIC AND

L1236 LYMPHOID TISSUE 6.0853 -0.57662408

HAEMATOPOIETIC AND

LP 1 LYMPHOID TISSUE 6.1029 -0.558150277

SNU620 STOMACH 6.1039 -0.557100629

MALME3M SKIN 6.1 12 •0.548598481

GSU STOMACH 6.1 172 •0.543140312

MCF7 BREAST 6.1256 -0.53432327

COLO800 SKIN 6.1272 ^■ 0.532643833

MKN7 STOMACH 6.1453 •0.513645206

SNU1 19 OVARY 6.1473 -0.51 154591

U1 18MG CENTRAL NERVOUS SYSTEM 6.1481 ^■ 0.510706192

HAEMATOPOIETIC AND

OCILY19 LYMPHOID TISSUE 6.1512 ^■ 0.507452283 RKN SOFT TISSUE 6.1579 •0.500419642 DV90 LUNG 6.1676 ^■ 0.490238057 NCIH1355 LUNG 6.171 ^■ 0.486669254

HAEMATOPOIETIC AND

KMM1 LYMPHOID TISSUE 6.1723 ■0.485304712 NCIH1 184 LUNG 6.1776 ^■ 0.479741578

HAEMATOPOIETIC AND

U937 LYMPHOID TISSUE 6.1777 ^■ 0.479636613

HAEMATOPOIETIC AND

EJM LYMPHOID TISSUE 6.1782 ■0.4791 1 1789 C32 SKIN 6.1786 -0.47869193

NCIH23 LUNG 6.1 854 •0.471554324

RERFLCAD 1 LUNG 6.1 862 ■0.470714606

T3M10 LUNG 6.1 867 •0.4701 89782

HAEMATOPOIETIC AND

U266B1 LYMPHOID TISSUE 6.1906 0.466096155 CAL54 KIDNEY 6.1949 ^■ 0.461582669

HAEMATOPOIETIC AND

DND41 LYMPHOID TISSUE 6.1979 ^■ 0.458433726 PC14 LUNG 6.2003 -0.455914571

HAEMATOPOIETIC AND

KMS1 1 LYMPHOID TISSUE 6.2008 -0.455389747 DMS53 LUNG 6.2061 -0.449826613

UPPER AEROD IGESTI VE

SNU1214 TRACT 6.2071 -0.448776965 GOS3 CENTRAL NERVOUS SYSTEM 6.2076 -0.448252141 TE8 OESOPHAGUS 6.21 19 -0.443738655 ECGI 10 OESOPHAGUS 6.2151 -0.440379781

HAEMATOPOIETIC AND

K052 LYMPHOID TISSUE 6.2174 -0.437965591 NCIH1793 LUNG 6.2189 -0.436391 1 19

HAEMATOPOIETIC AND

NB4 LYMPHOID TISSUE 6.219 -0.436286155

NCIH1 105 LUNG 6.2191 -0.436181 19

HAEMATOPOIETIC AND

OCILY10 LYMPHOID TISSUE 6.222 -0.43313721 1 NCIH69 LUNG 6.2243 -0.430723021 A673 BONE 6.2304 -0.424320168 HCC4006 LUNG 6.2335 -0.42106626

UPPER AEROD IGESTI VE

SCC9 TRACT 6.2351 -0.419386823 OAW28 OVARY 6.2381 -0.416237879 BXPC3 PANCREAS 6.2387 -0.415608091 ISTMES 1 PLEURA 6.2389 -0.415398161

HAEMATOPOIETIC AND

SKMM2 LYMPHOID TISSUE 6.2396 -0.414663408

NCIN87 STOMACH 6.24 -0.414243548

T98G CENTRAL NERVOUS SYSTEM 6.2412 -0.412983971

GP2D LARGE INTESTINE 6.2536 -0.399968337

FTC238 THYROID 6.2564 -0.397029323

HAEMATOPOIETIC AND

KMS27 LYMPHOID TISSUE 6.2607 -0.392515837 SNU201 CENTRAL NERVOUS SYSTEM 6.2618 -0.391361224 BC3C URINARY TRACT 6.266 -0.386952703

HAEMATOPOIETIC AND

RS411 LYMPHOID TISSUE 6.2689 -0.383908724

HAEMATOPOIETIC AND

TALL1 LYMPHOID TISSUE 6.2742 -0.37834559 RT4 URINARY TRACT 6.2742 -0.37834559 SKOV3 OVARY 6.2773 -0.375091681 RERFLCAD2 LUNG 6.2783 -0.374042033

HAEMATOPOIETIC AND

KHM1B LYMPHOID TISSUE 6.2859 -0.366064709

HAEMATOPOIETIC AND

KASUMI2 LYMPHOID TISSUE 6.2904 -0.361341294

HAEMATOPOIETIC AND

MOLT16 LYMPHOID TISSUE 6.2966 -0.354833477

HAEMATOPOIETIC AND

NUDUL1 LYMPHOID TISSUE 6.2966 -0.354833477 KMS1 8 HAEMATOPOIETIC AND 6.2973 -0.354098723 LYMPHOID TISSUE

MDAMB 175 VII BREAST 6.2981 -0.353259005

PvMGI OVARY 6.3019 -0.349270343

HAEMATOPOIETIC AND

KIJK LYMPHOID TISSUE 6.305 -0.346016434

HAEMATOPOIETIC AND

OCIAML5 LYMPHOID TISSUE 6.3062 -0.344756857

KMRC20 KIDNEY 6.3063 -0.344651892

LU65 LUNG 6.3082 -0.342657561

JIMT1 BREAST 6.3087 -0.342132737

SNU8 OVARY 6.3089 -0.341922807

KALS 1 CENTRAL NERVOUS SYSTEM 6.3098 -0.340978124

SCABER URINARY TRACT 6.322 -0.32817242

OVMANA OVARY 6.3268 -0.3231341 1

TUHR10TKB KIDNEY 6.3302 -0.319565307

HAEMATOPOIETIC AND

SUPM2 LYMPHOID TISSUE 6.33 14 -0.3 18305729

JMSU 1 URINARY TRACT 6.3317 -0.3 17990835

NCIH446 LUNG 6.3331 -0.3 16521328

COV434 OVARY 6.3341 -0.31547168

HCC38 BREAST 6.3361 -0.313372384 MRC2 KIDNEY 6.3393 -0.31001351 1

SNU478 BILIARY TRACT 6.3432 -0.305919884

HAEMATOPOIETIC AND

SUDHL1 LYMPHOID TISSUE 6.3444 -0.304660306

HAEMATOPOIETIC AND

CMLT1 LYMPHOID TISSUE 6.3494 -0.299412067

UACC257 SKIN 6.3508 -0.29794256

NCIH1339 LUNG 6.3509 -0.297837595

HAEMATOPOIETIC AND

M07E LYMPHOID TISSUE 6.351 1 -0.297627665

KMRC3 KIDNEY 6.3514 -0.2973 12771

NCIH1693 LUNG 6.3603 -0.287970905

HAEMATOPOIETIC AND

MMI S LYMPHOID TISSUE 6.3604 -0.28786594

HCC1 143 BREAST 6.361 1 -0.2871 31 1 86

KATOIII STOMACH 6.3642 -0.283877278

MDAMB453 BREAST 6.3691 -0.278734003

J82 URINARY TRACT 6.3718 -0.275899954

UPPER AERODIGESTIVE

CAL27 TRACT 6.3725 -0.2751 652

HS766T PANCREAS 6.3727 -0.274955271

HCT8 LARGE INTESTINE 6.3733 -0.274325482

NCIH158 I LUNG 6.3747 -0.272855975

HAEMATOPOIETIC AND

REH LYMPHOID TISSUE 6.3759 -0.271596397

MPP89 PLEURA 6.3817 -0.265508439

SNU761 LIVER 6.3819 -0.26529851 RH30 SOFT TISSUE 6.3841 -0.262989284

KURAMOCHI OVARY 6.3842 -0.26288432

HS936T SKIN 6.385 -0.262044601

HCC15 LUNG 6.3861 -0.260889989

HAEMATOPOIETIC AND

F36P LYMPHOID TISSUE 6.388 -0.258895657

PANC0504 PANCREAS 6.3894 -0.25742615

HAEMATOPOIETIC AND

NOMOl LYMPHOID TISSUE 6.3925 -0.254172242

SKUT1 SOFT TISSUE 6.3987 -0.247664425

CCK81 LARGE INTESTINE 6.4043 -0.241786397

NCIH21 1 LUNG 6.4058 -0.24021 1925

NH6 AUTONOMIC GANGLIA 6.4066 -0.239372206

BECKER CENTRAL NERVOUS SYSTEM 6.4161 -0.229400551

NCIH1869 LUNG 6.4177 -0.227721 1 14

ASPC1 PANCREAS 6.4186 -0.226776431

VMCUB1 URINARY TRACT 6.4199 -0.22541 1889

SNU398 LIVER 6.4206 -0.224677136

HAEMATOPOIETIC AND

THP1 LYMPHOID TISSUE 6.4214 -0.223837417

HAEMATOPOIETIC AND

HS61 1T LYMPHOID TISSUE 6.4224 -0.222787769

ONS76 CENTRAL NERVOUS SYSTEM 6.4253 -0.21974379

LOVO LARGE INTESTINE 6.4266 -0.218379248

GMS10 CENTRAL NERVOUS SYSTEM 6.4313 -0.213445903

RKO LARGE INTESTINE 6.4316 -0.213131009

ZR7530 BREAST 6.4339 -0.210716818

FU97 STOMACH 6.4421 -0.202109705

HAEMATOPOIETIC AND

OC1LY3 LYMPHOID TISSUE 6.4442 -0.199905445

HAEMATOPOIETIC AND

BV173 LYMPHOID TISSUE 6.4448 -0.199275656

NCIH1568 LUNG 6.4489 -0.1949721

NCIH1 155 LUNG 6.4497 -0.194132381

HAEMATOPOIETIC AND

JURKAT LYMPHOID TISSUE 6.4524 -0.191298332

CW2 LARGE INTESTINE 6.4567 -0.186784846

RD SOFT TISSUE 6.4567 -0.186784846

RERFLCAI LUNG 6.4571 -0.186364987

UPPER AEROD IGESTI VE

YD10B TRACT 6.4579 -0.185525268 SF295 CENTRAL NERVOUS SYSTEM 6.4581 -0.1853 15339

HAEMATOPOIETIC AND

JJN3 LYMPHOID TISSUE 6.4585 -0.18489548

HAEMATOPOIETIC AND

EB 1 LYMPHOID TISSUE 6.4633 -0.17985717 KNS60 CENTRAL NERVOUS SYSTEM 6.4642 -0.178912487

HAEMATOPOIETIC AND

X697 LYMPHOID TISSUE 6.4674 -0.175553613 TOV21G OVARY 6.4695 -0.173349353 JHH5 LIVER 6.4703 -0.172509634 OVTOKO OVARY 6.4718 -0.170935162 WM1799 SKIN 6.4744 -0.168206078

HAEMATOPOIETIC AND

PL21 LYMPHOID TISSUE 6.4754 -0.16715643

HAEMATOPOIETIC AND

CA46 LYMPHOID TISSUE 6.4772 -0.165267064

PATU8988S PANCREAS 6.479 -0.163377697 HCC44 LUNG 6.4794 -0.162957838

HAEMATOPOIETIC AND

KARPAS299 LYMPHOID TISSUE 6.4827 -0.159494 PANC0327 PANCREAS 6.4856 -0.156450021

UPPER AERODIGESTIVE

YD 8 TRACT 6.4856 -0.156450021

HAEMATOPOIETIC AND

GDM1 LYMPHOID TISSUE 6.4875 -0.15445569

IM95 STOMACH 6.4877 -0.154245761

HCT1 5 LARGE INTESTINE 6.4918 -0.149942204

WM793 SKIN 6.4939 -0.147737944

SHP77 LUNG 6.5008 -0.140495373

X8MGBA CENTRAL NERVOUS SYSTEM 6.5012 -0.140075514

OUMS23 LARGE INTESTINE 6.5015 -0.139760619

SW1 1 16 LARGE INTESTINE 6.5032 -0.137976218

NCIH1703 LUNG 6.5035 -0.137661324

HLF LIVER 6.5042 -0.13692657

HAEMATOPOIETIC AND

REC1 LYMPHOID TISSUE 6.5051 -0.135981887 ML1 THYROID 6.5066 -0.134407415 HOS BONE 6.5069 -0.134092521 SW837 LARGE INTESTINE 6.5072 -0.133777626

HAEMATOPOIETIC AND

EHEB LYMPHOID TISSUE 6.5124 -0.1283 19457

HUH28 BILIARY TRACT 6.5145 -0.1261 15197

MDAMB 157 BREAST 6.5173 -0.123176182

CHP212 AUTONOMIC GANGLIA 6.5178 -0.122651359

RMUGS OVARY 6.52 -0.120342133

NCIH2106 LUNG 6.5249 -0.1 15198858

S LMS 1 SOFT TISSUE 6.5254 -0.1 14674034

X647V URINARY TRACT 6.5257 -0.1 1435914

HS294T SKIN 6.5258 -0.1 14254175

CHAGOK1 LUNG 6.5292 -0.110685372

NCIH2228 LUNG 6.5304 -0.109425795

HAEMATOPOIETIC AND

MHHCALL3 LYMPHOID TISSUE 6.5324 -0.107326499 TE6 OESOPHAGUS 6.5328 -0.10690664

MHHES 1 BONE 6.5353 -0.10428252 X42MGBA CENTRAL NERVOUS SYSTEM 6.5397 -0.099664069 SH10TC STOMACH 6.5448 -0.0943 10865 HCC202 BREAST 6.5484 -0.090532132 ACHN KIDNEY 6.5518 -0.08696333

UPPER AERODIGESTIVE

SCC25 TRACT 6.5527 -0.086018646

PANC0403 PANCREAS 6.5578 -0.080665442

A2780 OVARY 6.5613 -0.076991674

EBC1 LUNG 6.5617 -0.076571815

SW620 LARGE INTESTINE 6.5658 -0.072268259

SKMEL31 SKIN 6.5659 -0.0721 63294

PK45H PANCREAS 6.5666 -0.07142854

NCIH2030 LUNG 6.5688 -0.0691 19315

SKMES I LUNG 6.5724 -0.065340583

HAEMATOPOIETIC AND

NAMALWA LYMPHOID TISSUE 6.5738 -0.063871 075 CAL12T LUNG 6.5741 -0.0635561 81

HAEMATOPOIETIC AND

HPBALL LYMPHOID TISSUE 6.5743 -0.063346251

HT1080 SOFT TISSUE 6.5745 -0.063136322

OE33 OESOPHAGUS 6.5749 -0.062716463

HAEMATOPOIETIC AND

SR786 LYMPHOID TISSUE 6.5751 -0.062506533

HAEMATOPOIETIC AND

NCIH929 LYMPHOID TISSUE 6.5755 -0.062086674

OVCAR4 OVARY 6.5755 -0.062086674

T47D BREAST 6.5764 -0.061 141991

HCC 1937 BREAST 6.5773 -0.060197308

SKHEP1 LIVER 6.5773 -0.060197308

HAEMATOPOIETIC AND

KMS26 LYMPHOID TISSUE 6.5778 -0.059672484

UPPER AEROD IGESTIVE

SNU1 066 TRACT 6.5779 -0.059567519

HAEMATOPOIETIC AND

SUPHD 1 LYMPHOID TISSUE 6.5802 -0.0571 53329

HAEMATOPOIETIC AND

L428 LYMPHOID TISSUE 6.5828 -0.054424244

PLCPRF5 LIVER 6.584 -0.053164667

MST021 1 H PLEURA 6.5871 -0.049910758

HAEMATOPOIETIC AND

GA10 LYMPHOID TISSUE 6.59 -0.046866779

UPPER AEROD IGESTIVE

HSC2 TRACT 6.59 -0.046866779 MKN74 STOMACH 6.591 1 -0.045712167

HAEMATOPOIETIC AND

TOLEDO LYMPHOID TISSUE 6.5926 -0.044137695

HAEMATOPOIETIC AND

KARPAS620 LYMPHOID TISSUE 6.5931 -0.043612871

CALU6 LUNG 6.5932 -0.043507906

SNU 1 196 BILIARY TRACT 6.5947 -0.041933434 HGC27 STOMACH 6.595 -0.04161854 NCIH716 LARGE INTESTINE 6.5964 -0.040149033

HAEMATOPOIETIC AND

HDMYZ LYMPHOID TISSUE 6.5974 -0.039099385

HAEMATOPOIETIC AND

A3KAW LYMPHOID TISSUE 6.6031 -0.0331 16392

SNGM ENDOMETRIUM 6.6038 -0.032381638

CAL851 BREAST 6.6074 -0.028602906

JHUEM2 ENDOMETRIUM 6.608 -0.0279731 17

LN18 CENTRAL NERVOUS SYSTEM 6.6106 -0.025244032

VMRCRCZ KIDNEY 6.6107 -0.025139067

TE10 OESOPHAGUS 6.6127 -0.023039772

CAKI2 KIDNEY 6.614 -0.021675229

PK 1 PANCREAS 6.6156 -0.019995793

TE1 OESOPHAGUS 6.6158 -0.019785863

IGR39 SKIN 6.6163 -0.019261039

NCIH1781 LUNG 6.6169 -0.01863125

A253 SALIVARY GLAND 6.6238 -0.01 138868

NCIH727 LUNG 6.6253 -0.009814208

G361 SKIN 6.6284 -0.006560299

TYKNU OVARY 6.6296 -0.005300722

UPPER AERODIGESTIVE

SNU1041 TRACT 6.6307 -0.004146109 JL1 PLEURA 6.6309 -0.00393618

SNU283 LARGE INTESTINE 6.6315 -0.003306391

HCT1 16 LARGE INTESTINE 6.632 -0.002781567

LS1034 LARGE INTESTINE 6.6323 -0.002466673

EF021 OVARY 6.633 -0.001731919

DMS1 14 LUNG 6.6335 -0.001207095

SNU1077 ENDOMETRIUM 6.6342 -0.000472342

DAOY CENTRAL NERVOUS SYSTEM 6.6343 -0.000367377

NCIH2342 LUNG 6.6346 -5.24824E-05

HAEMATOPOIETIC AND

MOLP8 LYMPHOID TISSUE 6.6347 5.24824E-05 BHT101 THYROID 6.6351 0.000472342 TE5 OESOPHAGUS 6.6355 0.000892201 PSN1 PANCREAS 6.6403 0.00593051 1

NCIH2170 LUNG 6.6424 0.008134771

HAEMATOPOIETIC AND

RCHACV LYMPHOID TISSUE 6.6426 0.008344701

HUH6 LIVER 6.6437 0.009499314

NCIH838 LUNG 6.6448 0.010653926

YAPC PANCREAS 6.6485 0.014537624

KYSE450 OESOPHAGUS 6.6505 0.016636919

RERFLCMS LUNG 6.6512 0.017371673

OVISE OVARY 6.6514 0.017581603 HT55 LARGE INTESTINE 6.6554 0.021780194

UPPER AERODIGESTIVE

SNU899 TRACT 6.662 0.02870787

NCIH226 LUNG 6.6624 0.02912773

X639V URINARY TRACT 6.6635 0.030282342

TE14 OESOPHAGUS 6.6652 0.032066744

MKN45 STOMACH 6.6662 0.0331 16392

UMUC3 URINARY TRACT 6.6662 0.0331 16392

HEC6 ENDOMETRIUM 6.6667 0.033641216

X253JBV URINARY TRACT 6.6694 0.036475265

SKMEL24 SKIN 6.6712 0.038364631

VMRCLCD LUNG 6.6718 0.03899442

DLD1 LARGE INTESTINE 6.6751 0.042458258

ECC12 STOMACH 6.6785 0.046027061

HAEMATOPOIETIC AND

WSUDLCL2 LYMPHOID TISSUE 6.6801 0.047706498

HAEMATOPOIETIC AND

PFEIFFER LYMPHOID TISSUE 6.6804 0.048021392

NCIH2087 LUNG 6.6806 0.048231322

NCIH2029 LUNG 6.6826 0.050330617

SJSA1 BONE 6.6844 0.052219984

A 172 CENTRAL NERVOUS SYSTEM 6.6858 0.053689491

SNU1033 LARGE INTESTINE 6.6873 0.055263963

TM31 CENTRAL NERVOUS SYSTEM 6.6885 0.05652354

X2313287 STOMACH 6.6886 0.056628505

SQ1 LUNG 6.6945 0.062821428

HAEMATOPOIETIC AND

SUPT1 1 LYMPHOID TISSUE 6.695 0.063346251

NCIH2023 LUNG 6.6954 0.06376611 1

HCC1569 BREAST 6.6976 0.066075336

TT2609C02 THYROID 6.7014 0.070063998

SW 1990 PANCREAS 6.7019 0.070588822

OVSAHO OVARY 6.7028 0.071533505

NCIH841 LUNG 6.7036 0.072373224

HAEMATOPOIETIC AND

ME1 LYMPHOID TISSUE 6.7039 0.0726881 18

COLO205 LARGE INTESTINE 6.7052 0.07405266

TCCSUP URINARY TRACT 6.7056 0.074472519

TE1 1 OESOPHAGUS 6.7063 0.075207273

TE4 OESOPHAGUS 6.707 0.075942026

NCIH1694 LUNG 6.7095 0.078566146

KP4 PANCREAS 6.7102 0.0793009

CL1 1 LARGE INTESTINE 6.71 1 0.080140618

NCIH596 LUNG 6.7123 0.08150516

HAEMATOPOIETIC AND

OCIAML3 LYMPHOID TISSUE 6.7152 0.084549139 HAEMATOPOIETIC AND

KMH2 LYMPHOID TISSUE 6.7155 0.084864034 PK59 PANCREAS 6.7163 0.085703752

HAEMATOPOIETIC AND

HDLM2 LYMPHOID TISSUE 6.7172 0.086648435 ES2 OVARY 6.7183 0.087803048

SKNDZ AUTONOMIC GANGLIA 6.7192 0.088747731

NCIH650 LUNG 6.7194 0.088957661

CAL62 THYROID 6.721 0.090637097

MDAMB231 BREAST 6.7222 0.091896675

HARA LUNG 6.7238 0.0935761 1 1

MFE319 ENDOMETRIUM 6.7242 0.093995971

LCLC103H LUNG 6.7269 0.09683002

OE19 OESOPHAGUS 6.7273 0.097249879

HT144 SKIN 6.7297 0.099769034

HEC251 ENDOMETRIUM 6.7301 0.1001 88893

HAEMATOPOIETIC AND

A4FUK LYMPHOID TISSUE 6.7317 0.10186833

HAEMATOPOIETIC AND

K562 LYMPHOID TISSUE 6.7319 0.102078259

HEC59 ENDOMETRIUM 6.7321 0.102288189

NCIH1341 LUNG 6.7337 0.103967626

A204 SOFT TISSUE 6.7338 0.10407259

OV7 OVARY 6.7346 0.104912309

OV90 OVARY 6.7381 0.108586076

HCC827 LUNG 6.7384 0.108900971

DU4475 BREAST 6.742 0.1 12679703

SKMEL1 SKIN 6.742 0.1 12679703

KYSE70 OESOPHAGUS 6.7428 0.1 13519422

CHP126 AUTONOMIC GANGLIA 6.7459 0.1 1677333

UPPER AERODIGESTIVE

DETROIT562 TRACT 6.7465 0.1 174031 19

HAEMATOPOIETIC AND

CMK LYMPHOID TISSUE 6.7483 0.1 19292485 X769P KIDNEY 6.7486 0.1 1960738

HAEMATOPOIETIC AND

DEL LYMPHOID TISSUE 6.7494 0.120447098

PANC0813 PANCREAS 6.751 0.122126535 COLO201 LARGE INTESTINE 6.752 0.123176182 SKNMC BONE 6.7533 0.124540725 CALU3 LUNG 6.7536 0.124855619

UPPER AERODIGESTIVE

SNU1076 TRACT 6.7574 0.128844281

HCC78 LUNG 6.7625 0.134197486

ESS 1 ENDOMETRIUM 6.7626 0.13430245

NCIH1755 LUNG 6.771 0.1431 19493 HPAFII PANCREAS 6.7751 0.147423049 CAKI 1 KIDNEY 6.7755 0.147842908

COL0783 SKIN 6.778 0.150467028

NCIH2405 LUNG 6.7785 0.150991852 NS81 CENTRAL NERVOUS SYSTEM 6.7793 0.15183157

HCC95 LUNG 6.7794 0.15 1936535

HAEMATOPOIETIC AND

HL60 LYMPHOID TISSUE 6.7796 0.152146465

UPPER AEROD IGESTIVE

FADU TRACT 6.7809 0.15351 1007

TE617T SOFT TISSUE 6.782 0.15466562

KMBC2 URINARY TRACT 6.7837 0.1 56450021

HCC 1 171 LUNG 6.7838 0.156554986

CAPAN1 PANCREAS 6.786 0.15886421 1

CORL88 LUNG 6.7915 0.164637275

UPPER AEROD IGESTIVE

PECAPJ49 TRACT 6.7927 0.165896852

SF126 CENTRAL NERVOUS SYSTEM 6.7933 0.166526641

GSS STOMACH 6.794 0.167261395

U87MG CENTRAL NERVOUS SYSTEM 6.7949 0.168206078

HEYA8 OVARY 6.7972 0.170620268

HT1376 URINARY TRACT 6.7994 0.172929493

COL0792 SKIN 6.7997 0.173244388

SKMEL2 SKIN 6.8019 0.175553613

NCIH460 LUNG 6.8048 0.178597592

KU1919 URINARY TRACT 6.8061 0.179962134

SNU407 LARGE INTESTINE 6.8062 0.180067099

HAEMATOPOIETIC AND

KU812 LYMPHOID TISSUE 6.8063 0.180172064

NCIH747 LARGE INTESTINE 6.8075 0.181431642

A101D SKIN 6.8089 0.182901 149

PATU8988T PANCREAS 6.8099 0.1 83950797

HS895T SKIN 6.81 18 0.185945128

HMC18 BREAST 6.8147 0.188989107

X253J URINARY TRACT 6.8153 0.189618895

TE9 OESOPHAGUS 6.8154 0.18972386

LSI 23 LARGE INTESTINE 6.8175 0.191928121

MCAS OVARY 6.8199 0.194447276

SW403 LARGE INTESTINE 6.8208 0.195391959

MDST8 LARGE INTESTINE 6.8209 0.195496924

RCM1 LARGE INTESTINE 6.8231 0.197806149

NCIH1650 LUNG 6.825 0.19980048

HAEMATOPOIETIC AND

RPMI8226 LYMPHOID TISSUE 6.8256 0.200430269

HAEMATOPOIETIC AND

SUDHL8 LYMPHOID TISSUE 6.8258 0.200640198 HEPG2 LIVER 6.8274 0.2023 19635 HT1 15 LARGE INTESTINE 6.8303 0.205363614 KYSE520 OESOPHAGUS 6.8305 0.205573544

ISHIKAWAHERAKLIO02ER ENDOMETRIUM 6.8313 0.206413262

RT1 12 URINARY TRACT 6.8313 0.206413262

SNU308 BILIARY TRACT 6.8314 0.206518227

HCC1806 BREAST 6.8314 0.20651 8227

NCIH2085 LUNG 6.8317 0.206833121

EF027 OVARY 6.832 0.207148015

NCIH2052 PLEURA 6.8321 0.20725298

UPPER AEROD IGESTI VE

HSC4 TRACT 6.8327 0.207882769

KYSE140 OESOPHAGUS 6.836 0.21 1346607

LC 1 SQSF LUNG 6.8361 0.21 1451572

KMRC1 KIDNEY 6.8362 0.21 1556537

HUPT3 PANCREAS 6.837 0.212396255

NCIH1838 LUNG 6.8375 0.212921079

T24 URINARY TRACT 6.8383 0.213760797

WM1 15 SKIN 6.8396 0.21512534

HAEMATOPOIETIC AND

KASUMI1 LYMPHOID TISSUE 6.8439 0.21 9638826

GAMG CENTRAL NERVOUS SYSTEM 6.8471 0.222997699

SBC5 LUNG 6.8494 0.22541 1889

WM2664 SKIN 6.8521 0.228245938

D283MED CENTRAL NERVOUS SYSTEM 6.857 0.233389213

MIAPACA2 PANCREAS 6.8607 0.23727291

HAEMATOPOIETIC AND

BL70 LYMPHOID TISSUE 6.8619 0.238532488 NCIH1623 LUNG 6.862 0.238637453

UPPER AEROD IGESTI VE

BHY TRACT 6.8627 0.239372206

OVCAR8 OVARY 6.8637 0.240421854

SNU840 OVARY 6.8651 0.241891361

CFPAC1 PANCREAS 6.8671 0.243990657

HS944T SKIN 6.8697 0.246719742

L 2 LUNG 6.8724 0.249553791

JHH1 LIVER 6.8737 0.250918333

OVKATE OVARY 6.8742 0.251443157

T84 LARGE INTESTINE 6.8791 0.256586432

SW 1573 LUNG 6.8813 0.258895657

KYSE30 OESOPHAGUS 6.8825 0.260155235

DANG PANCREAS 6.8825 0.260155235

SU8686 PANCREAS 6.8851 0.26288432

YD15 SALIVARY GLAND 6.8858 0.263619073

COLO680N OESOPHAGUS 6.8864 0.264248862

HAEMATOPOIETIC AND SUDHL6 LYMPHOID TISSUE 6.887 0.264878651 SNU626 CENTRAL NERVOUS SYSTEM 6.8886 0.266558087

SNU1 105 CENTRAL NERVOUS SYSTEM 6.8918 0.269916961

BT20 BREAST 6.8931 0.271281503

FTC 133 THYROID 6.8949 0.273170869

HAEMATOPOIETIC AND

P12ICHIKAWA LYMPHOID TISSUE 6.8951 0.273380799

NCIH292 LUNG 6.8954 0.273695693

JHH2 LIVER 6.9004 0.278943933

RCC10RGB KIDNEY 6.9009 0.279468757

JHOC5 OVARY 6.9036 0.282302806

X7860 KIDNEY 6.9057 0.284507067

AN3CA ENDOMETRIUM 6.9081 0.287026222

KP3 PANCREAS 6.909 0.287970905

HEC1 51 ENDOMETRIUM 6.9099 0.288915588

KE39 STOMACH 6.9103 0.289335447

HS822T BONE 6.91 15 0.290595024

A375 SKIN 6.91 17 0.290804954

MORCPR LUNG 6.9126 0.291749637

C2BBE 1 LARGE INTESTINE 6.9144 0.293639003

NCIH2452 PLEURA 6.9169 0.296263123

TCCPAN2 PANCREAS 6.9184 0.297837595

VMRCRCW KIDNEY 6.9222 0.301826257

NCIH810 LUNG 6.9222 0.301826257

PC3 PROSTATE 6.9226 0.3022461 16

MDAMB435S SKIN 6.9227 0.302351081

NCIH322 LUNG 6.9254 0.30518513

HAEMATOPOIETIC AND

MOLP2 LYMPHOID TISSUE 6.928 0.307914215

HCC366 LUNG 6.9295 0.309488687

KELLY AUTONOMIC GANGLIA 6.9352 0.31547168

AGS STOMACH 6.9378 0.31 8200764

MDAMB468 BREAST 6.9388 0.319250412

SNUC5 LARGE INTESTINE 6.939 0.319460342

HCC1 195 LUNG 6.941 0.321559638

NB1 AUTONOMIC GANGLIA 6.9466 0.327437666

NCIH2126 LUNG 6.9473 0.32817242

HAEMATOPOIETIC AND

HT LYMPHOID TISSUE 6.9476 0.328487314

SW48 LARGE INTESTINE 6.9505 0.331531293

QGP1 PANCREAS 6.9517 0.33279087

NUGC3 STOMACH 6.9527 0.33384051 8

SNU719 STOMACH 6.9544 0.33562492

SKES1 BONE 6.9576 0.338983793

OVK18 OVARY 6.9579 0.339298688

HEC1 B ENDOMETRIUM 6.9583 0.339718547 KLE ENDOMETRIUM 6.9584 0.33982351 1

HEC50B ENDOMETRIUM 6.9622 0.343812174

HAEMATOPOIETIC AND

TF1 LYMPHOID TISSUE 6.9682 0.3501 10061

AM38 CENTRAL NERVOUS SYSTEM 6.9715 0.353573899

HCC1954 BREAST 6.9728 0.354938441

MELHO SKIN 6.9769 0.359241998

EN ENDOMETRIUM 6.9773 0.359661857

HCC2108 LUNG 6.9789 0.361341294

X22RV1 PROSTATE 6.9813 0.363860449

PATU8902 PANCREAS 6.9874 0.370263301

LN229 CENTRAL NERVOUS SYSTEM 6.9883 0.371207984

Gil CENTRAL NERVOUS SYSTEM 6.9897 0.372677491

SNU213 PANCREAS 6.9923 0.375406576

COL0684 ENDOMETRIUM 6.993 0.376141329

SNU738 CENTRAL NERVOUS SYSTEM 6.9945 0.377715801

HAEMATOPOIETIC AND

JK1 LYMPHOID TISSUE 6.9966 0.379920062

KYSE510 OESOPHAGUS 6.9987 0.382124322

NCIH1299 LUNG 6.9991 0.382544181

IGROV 1 OVARY 7.0026 0.386217949

ACCMESOl PLEURA 7.0033 0.386952703

UPPER AEROD IGESTI VE

BICR16 TRACT 7.0071 0.390941365

HCC2279 LUNG 7.0072 0.39104633

PANC1 PANCREAS 7.0096 0.393565485

CCFSTTG1 CENTRAL NERVOUS SYSTEM 7.01 19 0.395979675

SNU668 STOMACH 7.0126 0.396714428

SW1271 LUNG 7.0143 0.39849883

HAEMATOPOIETIC AND

SUDHL4 LYMPHOID TISSUE 7.0162 0.400493161

GCT SOFT TISSUE 7.0174 0.401752738

TT THYROID 7.0183 0.402697421

DMS454 LUNG 7.019 0.403432175

LS I 80 LARGE INTESTINE 7.0225 0.407105943

SNU182 LIVER 7.0252 0.409939992

KNS62 LUNG 7.0253 0.410044957

OC314 OVARY 7.0273 0.412144253

RH41 SOFT TISSUE 7.0285 0.41340383

NCIH1373 LUNG 7.0318 0.416867668

BEN LUNG 7.0341 0.419281858

MESS A SOFT TISSUE 7.0401 0.425579746

HEC1A ENDOMETRIUM 7.0465 0.432297493

HAEMATOPOIETIC AND

L363 LYMPHOID TISSUE 7.0473 0.43313721 1

CAL29 URINARY TRACT 7.0497 0.435656366 HAEMATOPOIETIC AND

RAJI LYMPHOID TISSUE 7.0524 0.438490415 ZR751 BREAST 7.054 0.440169852 KYSE1 80 OESOPHAGUS 7.0541 0.440274817 LOXIMVI SKIN 7.058 0.444368444

UPPER AEROD IGESTI VE

YD38 TRACT 7.06 0.446467739

SNU410 PANCREAS 7.0646 0.45129612

NCIH2291 LUNG 7.0654 0.452135838

PANC0203 PANCREAS 7.0662 0.452975556

NCIH1 92 LUNG 7.0701 0.457069183

SW1088 CENTRAL NERVOUS SYSTEM 7.0786 0.465991 1 9

SKMEL30 SKIN 7.079 0.46641 105 M 12 LARGE INTESTINE 7.0792 0.466620979

HEC108 ENDOMETRIUM 7.0804 0.467880557

NCIH526 LUNG 7.0825 0.470084817

NCIH661 LUNG 7.0832 0.470819571

KYSE150 OESOPHAGUS 7.0859 0.47365362

TUHR4TKB KIDNEY 7.0861 0.47386355

U251MG CENTRAL NERVOUS SYSTEM 7.091 0.479006825

MK 1 STOMACH 7.0915 0^479531649

DMS273 LUNG 7.0958 0.484045135

HS683 CENTRAL NERVOUS SYSTEM 7.0975 0.485829536

HS746T STOMACH 7.1012 0.489713233

OAW42 OVARY 7.1038 0.49244231 8

HAEMATOPOIETIC AND

KYOl LYMPHOID TISSUE 7.1048 0.493491966 HS688AT SKIN 7.1049 0.493596931

HAEMATOPOIETIC AND

SIGM5 LYMPHOID TISSUE 7.1077 0.496535945

HUCCT1 BILIARY TRACT 7.1094 0.498320346

HS819T BONE 7.1097 0.498635241

HCC 1588 LUNG 7.1 149 0.50409341

KPL 1 BREAST 7.1 178 0.507137389

HAEMATOPOIETIC AND

E97 LYMPHOID TISSUE 7.1 1 87 0.508082072 HCC2218 BREAST 7.1208 0.510286332

HAEMATOPOIETIC AND

OCIM1 LYMPHOID TISSUE 7.1253 0.515009748

NCIH441 LUNG 7.1284 0.518263657

NCIH1092 LUNG 7.139 0.529389924

SKMEL28 SKIN 7.1392 0.529599854

HPAC PANCREAS 7.1394 0.529809784

SAOS2 BONE 7.1406 0.531069361

RL952 ENDOMETRIUM 7.1432 0.533798446

SKNAS AUTONOMIC GANGLIA 7.145 0.535687812 CAL148 BREAST 7.1477 0.538521861

DMS79 LUNG 7.1572 0.548493516

EFE184 ENDOMETRIUM 7.1614 0.552902038

HAEMATOPOIETIC AND

SUPT1 LYMPHOID TISSUE 7.167 0.558780066

NMCG1 CENTRAL NERVOUS SYSTEM 7.1746 0.56675739

NCIH358 LUNG 7.1753 0.567492144

TE441T SOFT TISSUE 7.1 772 0.569486475

MELJUSO SKIN 7.1877 0.580507778

IPC298 SKIN 7.1984 0.59173901

SW1353 BONE 7.1985 0.591843975

UPPER AEROD IGESTI VE

CAL33 TRACT 7.2038 0.597407109

SNU489 CENTRAL NERVOUS SYSTEM 7.2056 0.599296475

LCLC97TM1 LUNG 7.2086 0.602445419

UPPER AEROD IGESTIVE

BICR56 TRACT 7.2108 0.604754644 NCIH508 LARGE INTESTINE 7.2176 0.61 189225

UPPER AEROD IGESTIVE

HSC3 TRACT 7.2237 0.61 8295103

SNU878 LIVER 7.2238 0.618400067

CAMA1 BREAST 7.2254 0.620079504

LS41 1N LARGE INTESTINE 7.2279 0.622703624

YKG1 CENTRAL NERVOUS SYSTEM 7.2376 0.632885208

JHH6 LIVER 7.2377 0.632990173

KG1 C CENTRAL NERVOUS SYSTEM 7.238 0.633305068

BT474 BREAST 7.2422 0.637713589

SNU1079 BILIARY TRACT 7.2463 0.642017145

HAEMATOPOIETIC AND

KARPAS422 LYMPHOID TISSUE 7.2487 0.6445363

HEC265 ENDOMETRIUM 7.2509 0.646845526

NCIH2444 LUNG 7.2606 0.6570271 1

HAEMATOPOIETIC AND

NUDHL1 LYMPHOID TISSUE 7.2677 0.66447961 1

HAEMATOPOIETIC AND

AMOl LYMPHOID TISSUE 7.2764 0.67361 1547

HCC 1833 LUNG 7.2887 0.686522217

SNUC4 LARGE INTESTINE 7.2927 0.690720808

HDQP 1 BREAST 7.2935 0.691560527

OV56 OVARY 7.2957 0.693869752

HAEMATOPOIETIC AND

P3HR1 LYMPHOID TISSUE 7.2973 0.695549189

NUGC4 STOMACH 7.2991 0.697438555

U20S BONE 7.3013 0.69974778

SNU886 LIVER 7.3032 0.7017421 12

NCIH28 PLEURA 7.3081 0.706885386

SNU601 STOMACH 7.3091 0.707935034 ECC10 STOMACH 7.3182 0.71748683

LS513 LARGE INTESTINE 7.3 199 0.719271232

CAL120 BREAST 7.32 0.71 9376196

SNU1040 LARGE INTESTINE 7.3288 0.728613098

NCIH2171 LUNG 7.3416 0.742048591

HAEMATOPOIETIC AND

SUDHL5 LYMPHOID TISSUE 7.3508 0.751705352 BFTC905 URINARY TRACT 7.3514 0.752335141 HT29 LARGE INTESTINE 7.364 0.765560705 RPMI7951 SKIN 7.375 0.777106832

HAEMATOPOIETIC AND

AML193 LYMPHOID TISSUE 7.3753 0.777421726

HAEMATOPOIETIC AND

MECl LYMPHOID TISSUE 7.376 0.778156479

HEP3B217 LIVER 7.4062 0.809855846

SNU475 LIVER 7.4091 0.812899825

HUH1 LIVER 7.4298 0.834627537

HUPT4 PANCREAS 7.4555 0.861603488

IMR32 AUTONOMIC GANGLIA 7.4593 0.86559215 1

NCIH889 LUNG 7.4952 0.90327451 1

HCC2935 LUNG 7.5084 0.917129863

HAEMATOPOIETIC AND

MCI 16 LYMPHOID TISSUE 7.5146 0.92363768 X5637 URINARY TRACT 7.5183 0.927521377

HAEMATOPOIETIC AND

SKM1 LYMPHOID TISSUE 7.5234 0.932874582 SKBR3 BREAST 7.5494 0.960165427

HAEMATOPOIETIC AND

EM2 LYMPHOID TISSUE 7.5755 0.987561238

HAEMATOPOIETIC AND

RI 1 LYMPHOID TISSUE 7.5915 1.004355605

SIMA AUTONOMIC GANGLIA 7.6032 1.016636485

FUOV1. OVARY 7.6122 1.0260833 16

SNUC2A LARGE INTESTINE 7.6165 1.030596802

SNU61 LARGE INTESTINE 7.6228 1.037209584

CAPAN2 PANCREAS 7.6273 1.041933

SNU216 STOMACH 7.6319 1.04676138

HAEMATOPOIETIC AND

MOLM13 LYMPHOID TISSUE 7.646 1.061561416

HAEMATOPOIETIC AND

HUNS 1 LYMPHOID TISSUE 7.6648 1.081294796 HCC 1438 LUNG 7.7264 1.145953 108 NCIH2196 LUNG 7.7386 1.1 58758812 SNU466 CENTRAL NERVOUS SYSTEM 7.7589 1.180066665

HAEMATOPOIETIC AND

SUDHL10 LYMPHOID TISSUE 7.7977 1.220793004

UPPER AERODIGESTIVE

SNU46 TRACT 7.8035 1.226880962 CALU1 LUNG 7.8185 1.242625681 BFTC909 KIDNEY 7.9189 1.348010331

HAEMATOPOIETIC AND

JVM3 LYMPHOID TISSUE 7.961 1.392200508

HAEMATOPOIETIC AND

MHHCALL4 LYMPHOID TISSUE 8.031 1.465675862

HAEMATOPOIETIC AND

JURLMK1 LYMPHOID TISSUE 8.1 126 1.551327131

HAEMATOPOIETIC AND

KE37 LYMPHOID TISSUE 8.1 163 1.555210829

SI 17 SOFT TISSUE 8.2668 1.713182839

HAEMATOPOIETIC AND MS21 BM LYMPHOID TISSUE 8.3309 1.780465271

KYM1 SOFT TISSUE 8.4417 1.896766259

CO L95 LUNG 8.5762 2.037943903

MHHNB 11 AUTONOMIC GANGLIA 8.8255 2.299621 128

MDAMB361 BREAST 9.2909 2.788127266

Example 2. Identification of PDE3A as a putative target of DNMDP

Given the potent cell-selective growth inhibition by 6-(4-(diethylamino)-3-nitrophenyl)-5- methyl-4,5-dihydropyridazin-3(2H)-one (DNMDP), its mechanism of action was examined in more detail. To determine the molecular target of DNMDP, chemogenomic analysis was performed of the 766 tested cell lines, previously characterized for mutations, copy number, and gene expression features as part of the Cancer Cell Line Encyclopedia (CCLE, Barretina et al., 2012), to look for correlation between these genomic features and DNMDP sensitivity. Analysis of Pearson correlations between DNMDP sensitivity and expression of individual genes across the cell line set showed a strong correlation with expression of the PDE3A gene, encoding phosphodiesterase 3 A (Figure 5A). The correlation between DNMDP sensitivity and PDE3A expression is not perfect (Figure 18), and it is possible that some errors are introduced due to the high-throughput nature of the cell line sensitivity characterization, as manual validation for all 766 cell lines was not logistically feasible. Mutation and copy number features, in contrast, did not correlate with DNMDP sensitivity. Conversely, of 480 compounds tested, DNMDP sensitivity was the closest correlate of PDE3A expression (Figure 5B), indicating that cancer cell lines with high PDE3A expression were more distinctly sensitive to DNMDP than to any other tested compound. In contrast to the motivation of the initial screen, there was no correlation between TP53 mutation, or other measures of p53 function, and DNMDP sensitivity.

Given these results and the clear structural similarity of DNMDP to known PDE3 inhibitors, e.g., levosimendan and siguazodan (Figures 6A-6C), biochemical analysis of DNMDP against 19 phosphodiesterases representing 1 1 PDE super families was performed. At a concentration of 100 nM, DNMDP specifically inhibited both PDE3A and PDE3B, weakly inhibited PDE10, and had little or no detectable effect on other phosphodiesterases (Table 2). Because of the cellular correlation between PDE3A expression and DNMDP sensitivity, the in vitro inhibition of PDE3A and PDE3B by DNMDP, and the structural similarity of DNMDP to known PDE3 inhibitors, it was analyzed whether all PDE3 inhibitors would exhibit a similar cytotoxic profile to DNMDP. Surprisingly, there was almost no correlation between IC ₅₀ for in vitro enzymatic PDE3A inhibition and HeLa cell cytotoxicity across a series of tested compounds (Figure 5C and Figure 7A and 7B). Indeed, the potent PDE3 inhibitor trequinsin (PDE3 IC ₅₀ = 0.25 nM, Ruppert et al., Life Sci. 31 , 2037-2043, 1982) did not affect HeLa cell viability in any detectable way. Despite their differential effects on HeLa cell viability, the non-cytotoxic PDE3 inhibitor trequinsin and the potent cytotoxic compound DNMDP had similar effects on intracellular cAMP levels in forskolin- treated HeLa cells (Figures 8A and 8B). This result indicates that inhibition of the cAMP and cGMP hydrolysis functions of PDE3A was not sufficient for the cytotoxic activity of DNMDP.

Table 2: Results of phosphodiesterase inhibition reactions

PDE % inh. #1 % inh. #2 % inhibition

PDEIAI 3 7 5

PDE I B -5 0 -2

PDE1 C 2 9 5

PDE2A 6 10 8

PDE3A 95 95 95

PDE3B 98 97 97

PDE4A1A 14 18 16

PDE4B 1 21 20 21

PDE4C1 10 14 12

PDE4D3 14 16 15

PDE4D7 19 20 20

PDE5A1 16 16 16

PDE7A 24 20 22

PDE7B 5 1 1 8

PDE8A1 10 12 1 1

PDE9A2 0 5 2

PDE10A1 61 65 63

PDE 10A2 67 70 68

PDE1 1A 14 18 16

Example 3. Target validation of PDE3A

The complex relationship between phosphodiesterase 3A (PDE3 A) inhibition and cell killing, in which 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)-one (DNMDP) and some PDE3 inhibitors kill HeLa and other DNMDP-sensitive cells, whereas others PDE3 inhibitors do not affect cell viability, indicated several possible interpretations including: 1 ) the cytotoxic activity might be PDE3 -independent and due to action on a different protein though screening 234 kinases found no kinase inhibition by 10 μΜ DNMDP; 2) cytotoxic and non-cytotoxic PDE3 inhibitors might bind to different sites within the protein and exert distinct activities; or 3) the cytotoxic and non-cytotoxic PDE3 inhibitors might bind to the PDE3 active sites but have different effects on the conformation and activity of the protein. This third possibility might be unexpected, but allosteric modulators of PDE4 have been shown to bind the PDE4 active site and interact with upstream (UCR2), and downstream (CR3) regulatory domains and thereby stabilize specific inactive conformations (Burgin et al., Nat Biotechnol 28, 63-70, 2010). Most importantly, PDE4 competitive inhibitors and PDE4 allosteric modulators with similar IC ₅₀ s for cAMP hydrolysis in vitro had different cellular activities and safety profiles in animal studies (Burgin et al., Nat Biotechnol 28, 63- 70, 2010). To evaluate whether PDE inhibitors or other small molecules compete with DNMDP, the PHAPvMAKON 1600 collection of 1600 bioactive compounds (PHARMAKON 1600 is a unique collection of 1600 known drugs from US and International Pharmacopeia) was screened to identify compounds that were able to rescue cell death induced by DNMDP. HeLa cells were co-treated with 30 nM DNMDP (the EC ₇₀ concentration) and 20 μΜ of each bioactive compound. Cell viability after 48-hour treatment was assessed by ATP consumption as described earlier. The five most potent compounds that rescued cell death induced by DNMDP were all PDE inhibitors, and the three most potent compounds, levosimendan, milrinone, and cilostazol, were all selective PDE3 inhibitors (Figure 9A).

In follow-up experiments, it was confirmed that cilostamide, levosimendan, milrinone, and several other non-cytotoxic selective PDE3 inhibitors were able to rescue DNMDP cytotoxicity in a dose-dependent manner (Figure 9B). The most potent DNMDP competitor was trequinsin, with an "RC ₅₀ " (the concentration at which it achieved 50% rescue) of < 1 nM; in contrast, PDE5 inhibitors such as sildenafil and vardenafil, as well as the pan-PDE inhibitors idubulast and dipyridamole, were not effective competitors up to 10 μΜ concentrations in this assay (Figure 9B). This indicated that non-cytotoxic PDE3 inhibitors and DNMDP compete for binding to the same molecular target that is mediating the cytotoxic phenotype.

To identify the molecular target of DNMDP, an affinity purification was performed using an (i?)-des-nitro-DNMDP solid-phase tethered linker analogue (Figure 10A) incubated with HeLa cell lysate. This linker analogue had the same DNMDP cytotoxicity rescue phenotype as non-cytotoxic PDE3 inhibitors described above (Figure 10B), indicating that it too bound to the same molecular target. It was competed for the molecular target by adding either an excess of trequinsin or separate enantiomers of DNMDP, where only the (.K)-enantiomer was cytotoxic. Immunoblotting for PDE3A of the affinity purified material showed that PDE3 A indeed binds to the linker analogue. Binding of PDE3A to the linker analogue was blocked by both trequinsin and (i?)-DNMDP, but not by the non- cytotoxic enantiomer (5^-DNMDP (Figure 9C). Thus both trequinsin and (i?)-DNMDP prevented the binding of PDE3A to the tethered DNMDP analogue, and it was concluded that both molecules bind PDE3A directly.

Based on the observations that DNMDP-sensitive cells expressed high levels of PDE3A , and that DNMDP competed with non-cytotoxic inhibitors for PDE3A binding, it was hypothesized that DNMDP mediated its cytotoxic phenotype through the interaction with PDE3A and that PDE3A abundance was a direct cellular determinant of DNMDP sensitivity. To validate this hypothesis, the effect of reducing levels of PDE3A on the response to DNMDP was tested. A clustered regularly interspaced short palindromic (CRISPR)-associated CAS9 enzyme that was targeted with three guide RNAs (sgRNA) targeting three different sites in the PDE3A locus led to complete loss of PDE3A expression (Cong et al., Science 339, 819-823, 2013) sgRNA2 and sgRNA3 almost completely reduced PDE3A protein levels, whereas sgRNAl had a moderate effect on PDE3A expression (Figure 1 1 A). Importantly, both sgRNA2 and sgRNA3 led to significant rescue of toxicity by an active cytotoxic DNMDP analog, 3 (Figures 1 1A and 11B and Figures 5A-5C). Both sgRNA2 and sgRNA3 led to significant rescue of toxicity by DNMDP (Figure 1 1 C). Changes in proliferation rate or morphology in HeLa cells with reduced PDE3A expression were not observed, indicating that PDE3A was not required for cell survival. In an independent approach using an siRNA smart-pool containing four different siRNAs targeting PDE3A, PDE3A expression was reduced in HeLa cell line with a maximum efficiency of 70% between 24 and 72 hours after transfection. HeLa cells treated with siPDE3A had a higher EC ₅₀ to a DNMDP analog compared to the control siRNA condition (Figures 12A and 12B). Without being bound by theory it was concluded that DNMDP cytotoxicity requires PDE3A, and that DNMDP likely modulates the function of PDE3A.

Example 4. Determining the mechanism of action of DNMDP

The dependence of 6-(4-(diethylamino)-3-nitrophenyl)-5-methyl-4,5-dihydropyrid azin-3(2H)- one (DNMDP) cytotoxicity on phosphodiesterase 3A (PDE3A) protein abundance indicated a possible mechanism similar to that recently observed for lenalidomide, which acts by a neomorphic or hypermorphic mechanism by stabilizing an interaction between cereblon and IKAROS Family Zinc Finger 1 (IKZF1) and IKZF3 (Kronke et al., Science 343, 301-305, 2014; Lu et al., Science 343, 305- 309, 2014). In addition, PDE4 allosteric modulators, but not competitive inhibitors, have been shown to bind and stabilize a "closed" protein conformation that has independently been shown to uniquely bind the PDE4-partner protein DISC I (Millar et al. Science 310, 1 187-1 191 , 2005). The protein complexes in which PDE3A resides were characterized under normal conditions, and it was examined how these complexes change when PDE3A is bound to DNMDP or the non-cytotoxic PDE3 inhibitor trequinsin. PDE3A and interacting proteins from Hela cells were immunoprecipitated in the presence of DNMDP and trequinsin followed by labeling with isobaric stable isotope tags for relative abundance and quantitation by mass spectrometry (iTRAQ/MS, Figure 13A). PDE3A

immunoprecipitates from HeLa cells were enriched for multiple protein phosphatase subunits including protein phosphatase 2 subunits (PPP2CA, PPP2R1A, PPP2R1B, PPP2R2A, PPP2R2D), calcineurin (PPP3R1 , PPP3CA, Beca et al, Circ. Res. 112, 289-297, 2013), 14-3-3 (YWHAB, YWHAQ, YWHAG, YWHAZ, Pozuelo Rubio et al, Biochem. J. 392, 163-172, 2005), and tubulin (TUBA1 C, TUBA1B) family members (Figure 13B and Figure 14A). In addition, it was found that PDE3A and PDE3B reside in the same protein complex, which has been previously reported (Malovannaya et al., Cell 145, 787-799, 201 1).

Binding of DNMDP altered the composition of interacting proteins that were co- immunoprecipitated with PDE3A. Proteins that were specifically enriched in PDE3A

immunoprecipitates after treatment with DNMDP included Sirtuin 7 (SIRT7) and Schlafen 12

(SLFN12) (Figure 13C and Figure 14B). These proteins specifically interacted with PDE3A in the presence of DNMDP, and were not observed in the trequinsin treated control, whereas a known PDE3B interactor, abhydrolase domain-containing protein 15 (ABHD15, Chavez et al., Biochem. Biophys. Res. Commun. 342, 1218-1222, 2006), was enriched in the immunoprecipitate from trequinsin-treated cells (Figure 13C and Figure 14C). The interaction promoted by DNMDP between PDE3A and both SIRT7 and SLFN12 was validated with affinity reagents. Immunoprecipitation of endogenous PDE3 A in HeLa cells treated with DNMDP, but not DMSO or trequinsin, enhanced complex formation of ectopically expressed V5-tagged SIRT7 and SLFN12 with PDE3A, as evidenced by coimmunoprecipitation (Figure 19). Figure 20 further shows that DNMDP and (weakly) anagrelide, but not trequinsin, induced PDE3A and SFLN12 complex formation.

Similar to PDE3 A, overexpression of SLFN12 appears to have a cytotoxic effect in DNMDP sensitive cell lines, contributing to the difficulty of detecting SLFN12 in whole cell lysates.

The enhanced interaction of PDE3A with SIRT7 and SLFN12 indicated the possibility that one or more of these interacting proteins might contribute to DNMDP sensitivity. SIRT7 mRNA expression was relatively constant among all cells tested, but the co-expression of SLFN12 and

PDE3A mRNA showed a strong correlation with DNMDP sensitivity; almost all DNMDP-sensitive cell lines expressed high levels of SLFN12 (Figure 15A-15C). Importantly, almost half of sensitive cell lines expressing high levels of SLFN12 and PDE3A were found to be melanoma cell lines (Figure 15B). SLFN12 expression alone was also one of the top genes correlating with sensitivity to DNMDP, corroborating the hypothesis that SLFN12 could be functionally involved in DNMDP - induced cytotoxicity (Figure 16 A). Moreover, when correcting for PDE3A expression, SLFN12 expression was the top correlating gene with DNMDP sensitivity (Figure 16B). To assess whether SLFN12 is required for the cytotoxic phenotype of DMNDP, we reduced SLFN12 mRNA expression by 60% by knockdown with two shRNAs in HeLa cells (Figure 15D). Similar to reduction in PDE3A expression, reduction of SLFN12 expression did not result in cytotoxicity, and in fact decreased sensitivity to DNMDP (Figure 15E). These results show that SLFN 12, like PDE3A, is required for the cytotoxic phenotype of DMNDP. Characterization of normal expression of SLFN 12 and PDE3A by the GTEX consortium (Pierson, E. et al. PLoS Comput. Biol. 11, el004220 (2015)) shows low expression of SLFN12 in normal tissues, while high co-expression of both PDE3A and SLFN12 is rarely observed (Table 3). This could suggest that on-target toxicity of DNMDP and related compounds may be potentially limited. Table 3: RPKM values of SLFN12 and PDE3A expression in multiple healthy tissue types

Whole Blood 1.40 1.10 0.06 0.05 191

Figure 21 shows that SLFN 12 is lost in cells that have acquired resistance to DNMDP. Cell lines initially sensitive to DNMDP were made resistant by persistent exposure to DNMDP and subsequently analyzed by RNA-seq. One gene was downregulated in both HeLa and H2122: SLFN 12. Accordingly, a reduction in levels of SLFN 12 indicates that cells have become resistant to DNMDP and other PDE3A modulators. Figure 22 shows sensitization of a DNMDP -resistant cell line by expression of SLFN12 or expression of SFLN12 and PDE3A. Expression of SLFN12 was sufficient to confer DNMDP sensitivity to A549 cells. Adding PDE3A expression led to further sensitization.

Leiomyosarcomas are malignant smooth muscle tumors. Patient tumor samples from leiomyosarcomas were analyzed for PDE3A and SLFN12 expression to characterize sensitivity of leiomyosarcomas (LMS) to DNMDP. Leiomyosarcomas are thought to be sensitive to DNMDP due to prevalence among high purity TCGA samples expressing elevated levels of PDE3A and SLFN12 (Figure 23, Table 4). P value for association of biomarker expression with leiomyosarcoma lineage: 0.0001.

Table 4. Leiomyosarcomas Characterization

Differential scanning fluorimetry (DSF) was used to demonstrate binding of DNMDP to purified PDE3A catalytic domain, PDE3A(677-1 141). In this experiment, 5 μΜ hsPDE3A(640-l 141 ) was incubated in the absence or presence of 100 μΜ compounds, as indicated in Table 5. Binding buffer: 20 mM Hepes pH 7.4, 100 μΜ TCEP, 1 mM MgCl ₂ , 150 mM NaCl.

Table 5. Binding of DNMDP to PDE3A(677-1141)

Using chemogenomics, a class of compounds was discovered, exemplified by DNMDP, that targeted a novel cancer dependency by small-molecule modulation of PDE3A. These compounds bound PDE3 A in a mutually exclusive manner with non-cytotoxic PDE3 inhibitors and exerted a neomorphic or hypermorphic effect on the function of PDE3A, leading to a change in its protein- protein interactions. One unique protein-interaction partner, SLFN12, was highly expressed in DNMDP-sensitive cell lines, indicating a functional role in the pathway through which the cytotoxic signal was relayed. As a result, DNMDP was both selective and potent across a large panel of cancer cell lines.

Here, a novel cytotoxic compound was identified with great selectivity and low-nM potency against cancer cell lines across multiple lineages. Using gene-expression correlates for

chemogenomics, PDE3A was identified as the putative target of this small molecule, DNMDP. Interestingly, loss of PDE3A expression resulted in resistance to DNMDP. Moreover, PDE3A immunoprecipitation followed by isobaric stable isotope tags for relative abundance and quantitation by mass spectrometry (iTRAQ/MS) identified SLFN12 and SIRT7 as novel protein-protein interaction partners of PDE3A upon DNMDP binding, possibly due to allosteric modulation of the function of PDE3A. Importantly, SLFN12 expression was the top correlating gene with DNMDP sensitivity when corrected for PDE3A expression. Single gene or multi-gene expression correlations have shown to help elucidate the mechanism of action and relevant signaling pathways of small molecules. A novel biochemical target for cancer treatment was identified that is unlikely to have been found by target identification approaches such as loss-of-function screens or genomic analysis.

PDE3 A belongs to the superfamily of phosphodiesterases and together with PDE3B forms the PDE3 family. The PDE3 family has dual substrate affinity and hydrolyses both cAMP and cGMP. Expression of PDE3A is highest in the cardiovascular system, platelets, kidney, and oocytes (Ahmad et al., Horm Metab Res 44, 776-785, 2012). The clinical PDE3 inhibitor cilostazol has been developed to treat intermittent claudication, as PDE3A inhibition in platelets impairs activation and platelet coagulation (Bedenis et al., Cochrane Database Syst Rev 10, CD003748, 2014). Other PDE3 inhibitors, such as milrinone, amrinone, and levosimendan, are indicated to treat congestive heart failure, where the combination of vasodilation and elevated cardiac cAMP levels increases cardiac contractility (Movsesian et al., Curr Opin Pharmacol 1 1 , 707-713, 201 1). None of these clinical inhibitors were able to replicate the cytotoxic phenotype of DNMDP, indicating that cyclic nucleotide hydrolysis was not sufficient to induce cell death in DNMDP-sensitive cell lines.

Interestingly however, other PDE3 inhibitors such as zardaverine, anagrelide, and quazinone have been reported previously to have cell cytotoxic characteristics in a select number of cancer cell lines (Sun et al, PLoS ONE 9, e90627, 2014; Fryknas et al, J Biomol Screen 1 1 , 457-468, 2006). In concordance with the present findings, other PDE3 and PDE4 inhibitors were found not to replicate the cytotoxic phenotype of zardaverine where retinoblastoma protein retinoblastoma 1 (RB 1) expression was reported to separate zardaverine sensitive cell lines from non-sensitive cell lines (Sun et al., PLoS ONE 9, e90627, 2014). This finding was in contrast to the present data where a correlation between cytotoxic activities of DNMDP and copy-number or mRNA expression of RBI was not identified. Another PDE3 inhibitor, anagrelide, uniquely inhibited megakaryocyte differentiation, resulting in apoptosis. Other PDE3 inhibitors tested did not have this activity (Wang et al., Br. J. Pharmacol. 146, 324-332, 2005; Espasandin, Y. et al., J. Thromb. Haemost. n/a-n/a, 2015, doi: 10.1 1 1 1/jth.12850). It was hypothesized that the reported effects of zardaverine on cell viability and anagrelide on megakaryocyte differentiation are mediated through the same PDE3A modulation as described in this study.

Multiple PDE3 inhibitors were competitive inhibitors and have been shown to occupy the catalytic binding site of cAMP and cGMP (Card et al., Structure 12, 2233-2247, 2004; Zhan et al, Mol. Pharmacol. 62, 514-520, 2002). In addition, zardaverine has been co-crystalized in a complex with PDE4D, where it occupies the cAMP-binding site, and has been modeled to bind PDE3B in a similar manner (Lee et al., FEBS Lett. 530, 53-58, 2002). Given the structural similarity of DNMDP to zardaverine and that DNMDP inhibited both PDE3 A and PDE3B, it was hypothesized that the binding mode of DNMDP is very similar to that of zardaverine. This indicated that in addition to acting as a cAMP/cGMP-competitive inhibitor, DNMDP allosterically induces a conformation that is responsible for its cytotoxic phenotype. Allosteric modulation of phosphodiesterases has been described previously for PDE4, where small molecules bound in the active site and simultaneously interacted with regulatory domains that came across the PDE4 active site. As a result, allosteric modulators stabilized a protein conformation that has been shown to differentially bind different PDE4 partner proteins (Burgin et al., Nat Biotechnol 28, 63-70, 2010).

The study of proteins associated with PDE3A might illuminate both its normal function and the way in which PDE3A modulators such as DNMDP kill cancer cells. PDE3A interacted with protein phosphatase 2 subunits, which are implicated in oncogenic viral transformation and are mutated in human cancers (Nagao et al., Int. Symp. Princess Takamatsu Cancer Res. Fund 20, 177— 184, 1989; Imielinski et al, Cell 150, 1 107-1 120, 2012; Lawrence et al., Nature 499, 214-218, 2013), indicating a role for PDE3 A in cancer cell signaling. Even though these interactions were not induced by DNMDP binding, the importance of the protein phosphatases in cancer biology would warrant further research.

The enhanced interaction between PDE3A and S LFN12, facilitated by DNMDP binding to PDE3A, and the correlation between sensitivity to DNMDP with SLFN12 expression strongly indicated that it is necessary to understand the functional impact of the PDE3A-SLF 12 interaction. However, little is known at this time about the functional role of SLFN12 in human physiology and cancer biology. SLFN12 is part of the schlafen gene family that diverges largely between humans and rodents. The large difference is due to rapid gene evolution and positive selection (Bustos et al., Gene 447, 1-1 1 , 2009). Therefore, SLFN12 has no murine orthologue, preventing the study of SLFN 12 in a well-understood model organism. The single publication on SLFN12 showed modulation of prostate cancer cell lines after ectopic expression of SLFN12 (Kovalenko et al., J. Surg. Res. 190, 177-184, 2014). Additional studies into the function of SLFN12 and its interaction with PDE3A could elucidate the mechanism of DNMDP cytotoxicity. Two observations indicated that DNMDP acted as a neomorph or hypermorph on PDE3A function: 1) DNMDP-sensitive cancer cell lines did not depend on PDE3A expression for survival, but rather PDE3 A knock-down led to DNMDP resistance; and 2) DNMDP induced or enhanced protein-protein interactions upon binding to PDE3A.

Lenalidomide was an example of a small molecule that acted as a neomorph or hypermorph rather than as an enzymatic inhibitor. Lenalidomide modulated a specific protein-protein interaction between the cereblon ubiquitin ligase and Ikaros transcription factors, which were then subsequently targeted for degradation (Kronke et al., Science 343, 301-305, 2014; Lu et al., Science 343, 305-309, 2014). By analogy, DNMDP might directly stabilize a PDE3A-SLFN12 interaction, or DNMDP could allosterically stabilize a PDE3 conformation that binds SLFN12. Either of these mechanisms could result in a neo- or hypermorphic phenotype. Further characterization of the neomorphic phenotype induced by DNMDP might facilitate synthesis of small molecules that will not inhibit cyclic nucleotide hydrolysis by PDE3A. Toxicity profiles of such small molecules should differ from PDE3 inhibitors prescribed for cardiovascular indications.

This study has uncovered a previously unknown role for PDE3A in cancer maintenance, in which its function can be modified by a subset of PDE3 inhibitors, resulting in toxicity to a subset of cancer cell lines. These data indicated that DNMDP and its analogs had a hyper- or neomorphic effect on PDE3A, leading to cellular toxicity, which was corroborated by cells becoming less sensitive to DNMDP with decreasing levels of cellular PDE3A. These observations are comparable with other reports of allosteric modulation of phosphodiesterases (Burgin et al., Nat Biotechnol 28, 63-70, 2010), indicating that DNMDP and analogues may have similar effects on PDE3A. The exact mechanism of cell-selective cytotoxicity remains unknown for now; however, further studies into the novel interactions with SLFN12, and perhaps SIRT7, might be informative.

In summary, the study herein used differential cytotoxicity screening to discover a cancer cell cytotoxic small molecule, DNMDP. Profiling of DNMDP in 766 genomically-characterized cancer cell lines revealed stereospecific nanomolar efficacy in about 3% of cell lines tested. A search for genomic features that indicated sensitivity revealed that elevated PDE3A expression strongly correlated with DNMDP response. DNMDP inhibited PDE3A and PDE3B, with little or no activity towards other PDEs. However, unexpectedly, most other PDE3A inhibitors tested did not phenocopy DNMDP, including the potent and selective PDE3A inhibitor, trequinsin. Co-treatment of DNMDP- sensitive cells with trequinsin competed away the cancer cell cytotoxic activity of DNMDP, and knockout of PDE3A rescued the otherwise sensitive cells from DNMDP -induced cytotoxicity, leading us to hypothesize that PDE3A is required for cancer cell killing by DNMDP, which induces a neomorphic alteration of PDE3A. Mass spectrometric analysis of PDE3A immunoprecipitates alone or in the presence of DNMDP or trequinsin revealed differential binding of SLFN12 and SIRT7 only in the presence, of DNMDP . Similar to PDE3A, SLFN 12 expression levels were elevated in

DNMDP-sensitive cell lines, and knock down of SLFN12 with shRNA decreased sensitivity of cells to DNMDP, indicating that DNMDP -induced complex formation of PDE3A with SLFN12 is critical to the cancer cell cytotoxic phenotype. Results herein therefore implicate PDE3 A modulators as candidate cancer therapeutic agents and demonstrate the power of chemogenomics in small molecule discovery.

The experiments above were performed with the following methods and materials.

Compound library screening in NCI-HI 734 and A549 cell lines

1500 NCI-H1734 or 1000 A549 cells were plated in a 384-well plate in 40 μΐ of RPMI supplemented with 10% Fetal Bovine Serum and 1% Pen/Strep. 24 hours after plating, a compound- library of 1924 small molecules was added at a concentration of 10 μΜ. Staurosporine was used a positive control for cytotoxicity at a concentration of 10 μΜ, and DMSO was used a negative control at a concentration of 1 %. All compounds were incubated for 48 hours with indicated small molecules. After 48 hours, 384-well plates were removed from the incubator and allowed to cool to room temperature for 20 minutes. Cell viability was assessed by adding 40 μΐ of a 25%

CELLTITERGLO ^® (Promega) in PBS with a THERMO COMB I™ or multichannel-pipette and incubated for 10 minutes. The luminescence signal was read using a Perkin-Elmer En Vision.

Viability percentage was calculated by normalizing to DMSO controls.

Compound sensitivity testing in cell lines

1000 HeLa (DMEM), 1000 A549 (RPMI), 500 MCF-7 (DMEM), 4000 PC3 (F12-K), 1000 NCI-H2122 (RPMI) or 1500 NCI -HI 563 (RPMI) cells were plated in a 384-well plate in 40 μΐ of corresponding growth media supplemented with 10% Fetal Bovine Serum. 24 hours after plating, indicated compounds were added at indicated concentrations and incubated for 48 hours. Cell viability was assessed as described in Compound library screening in NCI-HI 734 and A549 cell lines.

Caspase activity in HeLa cells

1000 HeLa cells were plated in 384-well plate in 40 μΐ of corresponding growth media supplemented with 10% Fetal Bovine Serum. 24 hours after plating, indicated compounds were added at indicated concentrations and incubated for 48 hours. Caspase-Glo from Promega was added according to the manufacturers recommendations and luminescence was determined as described in Compound library screening in NCI-HI 734 andA549 cell lines. Large-scale cell-line viability measurements

The sensitivity of 777 cancer cell lines (CCLs) was measured drawn from 23 different lineages to DNMDP. Each cell line was plated in its preferred media in white opaque 1536-plates at a density of 500 cells/well. After incubating overnight, DNMDP was added by acoustic transfer at 16 concentrations ranging from 66.4 μΜ - 2 nM in 2-fold steps in duplicate (Labcyte Echo 555, Labcyte Inc., Sunnyvale, CA). After 72 hours treatment, cellular ATP levels were measured as a surrogate for viability (CELLTITERGLO ^® , Promega Corporation, Madison, WI) according to manufacturer's protocols using a ViewLux Microplate Imager (PerkinElmer, Waltham, MA) and normalized to background (media-only) and vehicle (DMSO)-treated control wells.

Concentration response curves were fit using nonlinear fits to 2- or 3-parameter sigmoid functions through all 16 concentrations with the low-concentration asymptote set to the DMSO- normalized value, and an optimal 8-point dose curve spanning the range of compound-sensitivity was identified. The area under the 8-point dose curve (AUC) was computed by numeric integration as a metric for sensitivity for further analysis. Similar sensitivity measurements have been obtained for a collection of 480 other compounds, enabling analyses that identify cell lines responding uniquely to DNMDP (see Broad Institute Cancer Therapeutics Response Portal, a dataset to identify

comprehensively relationships between genetic and lineage features of human cancer cell lines and small-molecule sensitivities for complete list of compounds). Correlation of sensitivity measurements with basal gene expression

Gene-centric robust multichip average (RMA)-normalized basal mRNA gene expression data measured on the Affymetrix GeneChip Human Genome U133 Plus 2.0 Array were downloaded from the Cancer Cell Line Encyclopedia (CCLE, a detailed genetic characterization of a large panel of human cancer cell lines; Barretina et al., Nature 483, 603-607, 2012). Pearson correlation coefficients were calculated between gene expression (18,988 transcripts) and areas under the curve (AUCs) across 760 overlapping CCLs. For comparisons across small molecules exposed to differing numbers of CCLs, correlation coefficients were transformed using Fisher's transformati on.

Chemistry Experimental Methods

General details

All reactions were carried out under nitrogen (N2) atmosphere. All reagents and solvents were purchased from commercial vendors and used as received. Nuclear magnetic resonance (NMR) spectra were recorded on a Bruker (300 or 400 MHz Ή, 75 or 101 MHz ¹³ C) spectrometer. Proton and carbon chemical shifts are reported in ppm (δ) referenced to the NMR solvent. Data are reported as follows: chemical shifts, multiplicity (br = broad, s = singlet, d = doublet, t = triplet, q = quartet, m = multiplet; coupling constant(s) in Hz). Flash chromatography was performed using 40-60 μπι Silica Gel (60 A mesh) on a Teledyne Isco Combiflash Rf. Tandem Liquid Chromatography/Mass Spectrometry (LC/MS) was performed on a Waters 2795 separations module and 3100 mass detector with a Waters Symmetry C18 column (3.5 μηι, 4.6 X 100 mm) with a gradient of 0-100% CH3CN in water over 2.5 min with constant 0.1% formic acid. Analytical thin layer chromatography (TLC) was performed on EM Reagent 0.25 mm silica gel 60-F plates. Elemental analysis was performed by Robertson Microlit Laboratories, Ledgewood NJ.

Synthesis of (R)-DNMDP

In 5 mL of acetic anhydride, 2.00 g (9.84 mmol) of (R)-6-(4-aminophenyl)-5-methyl-4,5- dihydropyridazin-3(2 /)-one (A, Toronto Research Chemicals) was stirred 1 hour before addition of 30 mL water, filtration, rinsing the solids with water and drying to yield 2.20 g of product B (91%). ¾ NMR (300 MHz, DMSO-d ₆ ) δ 10.92 (s, 1H), 10.13 (s, 1H), 7.74 (d, J= 8.9, 2H), 7.65 (d, 7= 8.8, 2H), 3.41 - 3.33 (m, 1H), 2.68 (dd, J= 6.8, 16.8, 1H), 2.23 (d, J= 16.7, 1H), 2.08 (s, 3H), 1.07 (d, J= 7.3, 3H). ¹³ C NMR (75 MHz, DMSO-d ₆ ) δ 168.50, 166.27, 152.25, 140.27, 129.24, 126.24, 1 18.70, 33.47, 26.91, 24.02, 15.87. HPLC: R _t 0.72 min, purity > 95%. MS: 246 (M + l).

To 3.09 g of B (15.3 mmol) dissolved in 30 mL of sulfuric acid and cooled in an ice bath was added 0.72 mL of 90% nitric acid (15 mmol) in 8 mL sulfuric acid via an addition funnel over 10 minutes. After stirring 1 hour the mixture was poured onto ice. The yellow solid was filtered off and the water was rinsed several times with EtOAc before drying and combining with the yellow solid. Chromatography with 40-60%> EtOAc in hexane yielded 1.12 g (25%) of product as a yellow solid which was recrystallized from EtOAc. 'H NMR (300 MHz, DMSO-d ₆ ) 5 1 1.13 (s, 1H), 10.41 (s, 1H), 8.25 (d, J= 1.8, 1H), 8.07 (dd, J= 1.8, 8.6, 1H), 7.71 (d, /= 8.6, 1H), 3.55 - 3.40 (m, 1H), 2.74 (dd, J = 6.9, 16.8, 1H), 2.27 (d, J= 16.8, 1H), 2.09 (s, 3H), 1.08 (d, J= 7.2, 3H). ¹³ C NMR (75 MHz, DMSO-d6) 8 168.57, 166.31, 150.37, 142.19, 131.69, 131.32, 130.60, 125.07, 121.70, 33.30, 26.81 , 23.44, 15.64. TLC: Rf 0.25 (1 : 1 EtOAc:hexane). HPLC: R _t 0.87 min, purity > 95%. MS: 291 (M + 1 ). HRMS Exact Mass (M + l) : 291.1088. Found: 291.1091

To 58 mg of C (0.20 mmol) dissolved in 10 mL of MeOH was added a solution of 48 mg NaOH (1.2 mmol) in 0.5 mL water. After 1 hour the reaction was concentrated, water was added and rinsed with EtOAc, the EtOAc was dried and concentrated to give 48 mg (93%) of product D. ^l H

NMR (300 MHz, DMSO-d6) δ 10.92 (s, 1 H), 8.28 (d, J= 2.0, 1H), 7.87 (dd, J= 2.1 , 9.0, 1H), 7.76 (s, 2H), 7.06 (d, J= 9.0, 1H), 3.33 (s, 1H), 2.67 (dd, J= 6.8, 16.8, 1H), 2.22 (d, J= 16.6, 1 H), 1.06 (d, J = 7.3, 3H). ¹³ C NMR (75 MHz, DMSO-d ₆ ) δ 166.25, 151.12, 146.69, 132.72, 129.80, 122.57, 122.19, 1 19.80, 33.43, 26.70, 15.77. MS: 249 (M + l ).

To 35 mg of amine D (0.14 mmol) dissolved in 0.5 mL Dimethylformamide (DMF) was added 70 mg of acetaldehyde (1.6 mmol) and 170 mg of NaBH(OAc) ₃ (0.80 mmol) and 10 μί, (0.2 mmol) of HO Ac. After stirring 3 hours, water and EtOAc were added, the EtOAc separated, dried, concentrated and chromato graphed with 30-50%) EtOAc in hexane to isolate 3 mg of the (R)-DNMDP (7%o). The synthesized material was identical to purchased racemic material by TLC, HPLC and Ή NMR. Ή NMR (300 MHz, CDC1 ₃ ) δ 8.58 (s, 1H), 8.04 (d, J= 2.3, 1H), 7.84 (dd, J= 2.3, 9.0, 1 H), 7.1 1 (d, J= 9.0, 1H), 3.30-3.36 (m, 1H), 3.26 (q, /= 7.1 , 4H), 2.71 (dd, .7= 6.8, 16.9, 1 H), 2.48 (d, J = 17.0, 1H), 1.25 (d, J= 7.4, 3H), 1.16 (t, J= 7.1 , 6H). TLC: Rf 0.25 (1 : 1 EtOAc :hexane). HPLC: R _t 1.27 min, purity > 95%. MS: 305 (M + 1). Exact Mass (M + 1 ): 305.1608 Found: 305.1616. ¹³ C NMR (75 MHz, CDC1 ₃ , purchased material) δ 166.28, 152.02, 145.24, 141.21 , 129.77, 124.94, 123.94, 121.00, 46.10, 33.80, 27.81 , 16.24, 12.56.

The optical purity of (R)-DNMDP was determined using chiral SCF chromatography and comparison to commercially available racemic material: Column: ChiralPak AS-H, 250 x 4.6 mm, 5μπι, Mobile Phase Modifier: 100% Methanol, Gradient: 5 to 50% Methanol over 10 minutes, Flow Rate: 4 mL/min, Back Pressure: 100 bar, Column Temperature: 40 C. UV detection was from 200- 400 nm. Retention times of separated isomers: 5.36, 6.64 minutes; retention time of (R)-DNMDP, 6.60 minutes, 1 : 19 ratio of enantiomers detected.

2. To 200 mg (0.98 mmol) of A dissolved in 5 mL of MeOH was added 87 mg of acetaldehyde (2.0 mmol), 1 13 uL of HOAc (2.0 mmol ) and 124 mg (2.0 mmol) of NaBH ₃ CN and the reaction was stirred overnight at room temperature. The next day the same quantity of reagents were added and the reaction stirred another 24 hours. The mixture was concentrated and partitioned between CH ₂ C1 ₂ and water, the CH ₂ C1 ₂ was separated, dried, and concentrated before chromatography with 20-40% EtOAc in hexane isolated 210 mg of product as a white solid (82%). ^l NMR (300 MHz, CDC1 ₃ ) δ 8.95 (s, 1H), 7.64 (d, J= 8.7, 2H), 6.66 (d, /= 8.7, 2H), 3.37 (dd, /= 9.6, 16.4, 5H), 2.67 (dd, J= 6.5, 16.8, 1H), 2.43 (d, J= 16.8, 1H), 1.41 - 1.02 (m, 10H). ¹³ C NMR (75 MHz, CDC1 ₃ ) δ 166.82, 154.55, 148.79, 127.32, 120.81 , 1 1 1.08, 44.32, 33.92, 27.74, 16.37, 12.50. TLC: Rf 0.25 (1 : 1 EtOAc:hexane). HPLC: R _t 1.05 min, purity > 95%. MS: 260 (M + l). HRMS Exact Mass (M + 1): 260.1757. Found: 260.1764

3. To 200 mg (0.984 mmol) of A dissolved in 1 mL of Dimethylformamide (DMF) was added 250 μΐ _^ (2.00 mmol) of bis (2-bromoethyl) ether and 400 mg of K2C03 and the mixture was stirred overnight at 60 °C. The next day another 250 μΕ of bis (2-bromoethyl) ether and 170 mg of K2C03 were added. After 3 hours, EtOAc and water were added, the water was rinsed with EtOAc, the combined EtOAc washes were dried and concentrated. Chromatography with 0-4% MeOH in CH2C12 yielded 125 mg of product (46%). ¾ NMR (300 MHz, CDC1 ₃ ) δ 8.61 (s, 1H), 7.68 (d, J= 8.8, 2H), 6.92 (d, = 8.8, 2H), 3.99 - 3.76 (m, 4H), 3.44 - 3.31 (m, 1H), 3.29 - 3.22 (m, 4H), 2.70 (dd, J = 6.7, 16.8, 1H), 2.46 (d, J = 16.7, 1H), 1.24 (d, J = 7.3, 3H). ¹³ C NMR (75 MHz, CDC1 ₃ ) δ 166.64, 154.05, 152.18, 127.10, 125.33, 1 14.73, 66.69, 48.33, 33.93, 27.94, 16.36. TLC: R _f 0.1 (1 :50 MeOH:CH ₂ Cl ₂ ). HPLC: R _t 1.05 min, purity > 95%. MS: 274 (M + 1). HRMS: calcd. 274.1556 (M + 1); found 274.1552. Anal. Calcd. for C ₁₅ H ₁₉ N ₃ 0 ₂ : C, 65.91 ; H, 7.01 ; N, 15.37; Found. 65.81 , H, 6.66, N,

DNMDP-2L. To 130 mg of A (0.64 mmol) dissolved in 0.4 mL of Dimethylformamide (DMF) was added 100 mg oftert-butyl 2-(2-(2-bromoethoxy)ethoxy)-ethyl carbamate (Toronto Research Chemical, 0.32 mmol) and 90 mg of K ₂ C0 ³ (64 mmol) and the mixture was stirred at 60 overnight. After cooling, water was added and rinsed several times with EtOAc. The combined EtOAc layers were dried, concentrated, and chromatographed with 50-70% EtOAc to yield 81 mg of product (58%). ¾ NMR (300 MHz, CDC1 ₃ ) δ 9.06 (s, 1H), 7.59 (d, = 8.8 Hz, 2H), 6.62 (d, J= 8.8 Hz, 2H), 5.15 (s, 1H), 4.53 (s, 1H), 3.72 (t, J = 5.2 Hz, 2H), 3.65 (s, 4H), 3.55 (t, J = 5.2 Hz, 2H), 3.32 (m, 5H), 2.67 (dd, J = 16.8, 6.7 Hz, 1H), 2.42 (d, J = 16.4 Hz, 1H), 1.44 (s, 9H), 1.22 (d, J = 7.4 Hz, 3H). ¹³ C NMR (75 MHz, CDC1 ₃ ) δ 166.83, 155.99, 154.45, 149.64, 127.33, 123.24, 112.58, 79.28, 70.30, 70.26, 70.22, 69.45, 43.14, 40.39, 33.96, 28.43, 27.89, 16.40; HPLC: R _t 2.50 min (7.5 min run), purity > 95%. MS: 435 (M + 1). This product (0.19 mmol) was dissolved in 1 mL MeOH and to the solution was added acetaldehyde (50 uL, 0.89 mmol ), 10 uL HOAc (0.2 mmol) and 12 mg NaBH ₃ CN (0.19 mmol). After 1 hour, NaHC0 ₃ (aq) and CH ₂ C1 ₂ were added, the CH ₂ C1 ₂ was separated and the water washed twice with CH ₂ C1 ₂ . The combined CH ₂ C1 ₂ was dried, concentrated, and chromatography with 60-70% EtOAc in hexane yielded 71 mg of product as a clear oil (82%). Ή NMR (400 MHz, CDC1 ₃ ) δ 8.91 (s, 1H), 7.63 (d, J = 8.9 Hz, 2H), 6.69 (d, J = 8.9 Hz, 2H), 5.07 (s, 1H), 3.65 (t, J = 6.0 Hz, 2H), 3.61 (s, 4H), 3.55 (dt, J = 9.9, 5.5 Hz, 4H), 3.46 (q, J = 7.0 Hz, 2H), 3.38 - 3.22 (m, 3H), 2.67 (dd, J = 16.8, 6.7 Hz, 1H), 2.43 (d, J = 16.7 Hz, 1H), 1.45 (s, 10H), 1.23 (d, J = 7.3 Hz, 3H), 1.18 (t, J = 7.0 Hz, 3H). ¹³ C MR (101 MHz, CDC1 ₃ ) δ 166.84, 155.96, 154.46, 148.89, 127.35, 121.38, 111.28, 79.22, 70.68, 70.27, 70.24, 68.74, 49.95, 45.49, 40.32, 33.97, 28.43, 27.80, 16.43, 12.14. R _t 2.99 min (7.5 min run), purity > 95%. MS: 463 (M + 1).

Attachment to resin

To a solution of 18 mg of DNMDP-2L (0.04 mmol) in 0.8 mL of CH ₂ C1 ₂ was added 0.2 mL of trifluoroacetic acid (TFA) and the solution was stirred 2 h before concentration and dissolution in 0.5 mL DMSO. To this was added 10 uL of Et ₃ N (0.07 mmol) and 12 mg of TV.N'-disuccinimidyl carbonate (DSC) (0.05 mmol) and the solution was stirred overnight. LC analysis indicated the reaction was not complete, another 25 mg of Ν,Ν'-disuccinimidyl carbonate (0.1 mmol) was added. LC analysis after 2 hours showed ca. 5:1 ratio of DSC produc amine. A 1 mL sample of Affi-Gel

102 resin was rinsed five times with DMSO with a centrifuge, then suspended in 0.5 mL DMSO. To the resin was added 30 uL of the DSC product solution and 25 uL Et3N and the mixture was swirled. After 2 days, LC analysis of the DMSO solution showed complete disappearance of the DCS adduct; the underivatized amine was still present. The DMSO was removed by centrifuge and decanted and the resin was rinsed several times with DMSO and stored in PBS buffer.

Bioactives screen to rescue DNMDP induced cytotoxicity

1000 HeLa cells were plated in a 384-well plate in 40 μΐ of DMEM supplemented with 10% Fetal Bovine Serum and 1%> Pen/Strep. 24 hours after plating, a compound-library of 1600 bioactive molecules (Pharmacon) was added at a concentration of 20 μΜ. In parallel to bioactive compound incubation, DNMDP was added to a final concentration of 30 nM and incubated for 48 hours. Cell viability was assessed as described in Compound library screening in NCI-H1734 and A549 cell lines.

Linker- affinity purification of molecular target of DNMDP and immunoblotting

HeLa cells were washed with ice-cold PBS before lysed with NP-40 lysis buffer (150 mM

NaCl, 10% glycerol, 50 mM Tris-Cl pH 8.0, 50 mM MgCl ₂ , 1 % NP-40) supplemented with EDTA- free protease inhibitors (Roche) and phosphatase inhibitor mixtures I and II (Calbiochem). Cell lysates were incubated on ice for at least 2 minutes and subsequently centrifuged for 10 minutes at 4° C at 15,700 x g after which the supernatant was quantified using BCA protein assay kit (Pierce). 200 μg total HeLa cell lysate was incubated with 3 μΐ Affi-Gel 102 resin (BioRad) coupled to affinity linker DNMDP -2L in a total volume of 400 μΐ for four hours. Prior to incubation, indicated compounds were added to affinity purifications at a final concentration of 10 μΜ. Samples were washed three times with lysis buffer containing corresponding compound concentrations of 10 μΜ. Proteins bound to Affi-Gel 102 resin were reduced, denatured, and separated using Tris-Glycine gels (Novex) and transferred to nitrocellulose membranes using the iBlot transfer system (Novex).

Membranes were incubated overnight at 4° C with primary antibodies against PDE3A (1 : 1000, Bethyl). Incubation with secondary antibodies (1 :20,000, LI-COR Biosciences) for two hours at room temperature and subsequent detection (Odyssey Imaging System, LI-COR Biosciences) were performed according to manufacturer's recommendations.

PAR '-cleavage immunoblotting

HeLa cells were treated with indicated concentration of DNMDP and staurosporine for 36 hours. HeLa cells were lysed and processed as described in Linker- affinity purification of molecular target of DNMDP and immunoblotting. Membranes were incubated with an antibody against PARP (1 : 1000, Cell Signaling #9532) and actin and subsequently imaged as described in Linker- affinity purification of molecular target of DNMDP and immunoblotting.

Targeting PDE3A locus using CRISPR

CRISPR target sites were identified using the MIT CRISPR Design Tool (online MIT CRISPR design portal). For cloning of sgRNAs, forward and reverse oligos were annealed, phosphorylated and ligated into BsmBI-digested pXPR_BRD001. Oligo sequences are as follows:

To produce lentivirus, 293T cells were co-transfected with pXPR_BRD001, psPAX2 and pMD2.G using calcium phosphate. Infected HeLa cells were selected with 2ug/ml of puromycin. Reduction of PDE3A expression using siRNA

HeLa cells were plated in 96-well plates and transfected after 24 hours with PDE3 A and Non- Targeting siRNA smartpools (On Target Plus, Thermo Scientific) according to the manufacturers recommendations. HeLa cell lysate was obtained 24 hours and 72 hours after transfection and immunoblotted for PDE3A and Actin (1 :20,000, Cell Signaling) as described in Linker-affinity purification of molecular target of DNMDP and immunoblotting. HeLa cells were treated for 48 hours with indicated concentrations of Compound 3. Cell viability was assessed as described in Compound library screening in NCI-H1734 and A549 cell lines.

Measuring cellular cAMP concentrations in HeLa cells

5000 HeLa cells were plated in 96-well plates. 24 hours after plating, HeLa cells were incubated for one hour with indicated compounds at indicated concentrations. cAMP levels were determined with the CAMP-GLO™ assay (Promega) according to the manufacturers

recommendations. Cellular concentrations of cAMP were determined by normalizing to a standard curve generated according to the manufacturers recommendations.

Extended Proteomics Methods for PDE3A-protein interaction studies

Lmmunoprecipitation ofPDE3A in HeLa cells

HeLa cells were treated for four hours prior to lysis with 10 μΜ of indicated compounds: DMSO, DNMDP and trequinsin. HeLa cells were lysed with ModRipa lysis buffer (l%NP-40: 50 mM Tris-HCl, pH 7.8, 150 mM NaCl, 0.1% sodium deoxycholate, 1 mM EDTA) supplemented with protease and phosphatase inhibitors as described in Linker-affinity purification of molecular target of DNMDP and immunoblotting, and indicated compounds as described above to a final concentration of 10 μΜ. 13 mg of HeLa total cell lysate was incubated with 0.5% PDE3A antibody (Bethyl) and incubated overnight. Blocking peptide (Bethyl) against the PDE3A antibody was added

simultaneously with the PDE3A antibody in the corresponding condition. Total cell lysate and antibody mixture was then incubated with 10 μΐ Protein A Plus Agarose (Fisher Scientific) for 30 minutes at 4° C. Protein A Plus Agarose was then washed two times with lysis buffer containing indicated compounds at a concentration of 10 μΜ. Finally, Protein A Plus Agarose was washed once with lysis buffer containing no NP-40 and indicated compounds at a concentration of 10 μΜ. On-bead digest

The beads from immunopurification were washed once with IP lysis buffer, then three times with PBS, the three different lysates of each replicate were resuspended in 90 uL digestion buffer (2M Urea, 50 mM Tris HC1), 2 ug of sequencing grade trypsin added, 1 hour shaking at 700 rpm. The supernatant was removed and placed in a fresh tube. The beads were then washed twice with 50 uL digestion buffer and combined with the supernatant. The combined supernatants were reduced (2 uL 500 mM DTT, 30 minutes, room temperature), alkylated (4 uL 500 mM IAA, 45 minutes, dark) and a longer overnight digestion performed: 2 ug (4 uL) trypsin, shake overnight. The samples were then quenched with 20 uL 10% folic acid (FA) and desalted on 10 mg SEP-PAK ^® columns. iTRAQ labeling of peptides and strong cation exchange (sex) fractionation

Desalted peptides were labeled with isobaric tags for relative and absolute quantification (iTRAQ)- reagents according to the manufacturer's instructions (AB Sciex, Foster City, CA). Peptides were dissolved in 30 μΐ of 0.5 M TEAB pH 8.5 solution and labeling reagent was added in 70 ul of ethanol. After 1 hour incubation the reaction was stopped with 50 mM Tris/HCl pH 7.5.

Differentially labeled peptides were mixed and subsequently desalted on 10 mg SEP-PAK ^® columns.

SCX fractionation of the differentially labelled and combined peptides was done as described in Rappsilber et al. (Rappsilber et al., Nat Protoc 2, 1896-1906, 2007), with 6 pH steps (buffers- all contain 25% acetonitrile) as below:

1 : ammonium acetate 50 mM pH 4.5,

2: ammonium acetate 50 mM pH 5.5,

3 : ammonium acetate 50 mM pH 6.5,

4: ammonium bicarbonate 50 mM pH 8,

5 : ammonium hydroxide 0.1% pH 9,

6 : ammonium hydroxide 0.1% pH 11.

Empore SCX disk used to make stop-and-go-extraction-tips (StageTips) as described in the paper. MS analysis

Reconstituted peptides were separated on an online nanoflow EASY-NLC™ 1000 UHPLC system (Thermo Fisher Scientific) and analyzed on a benchtop Orbitrap Q EXACTIVE™ mass spectrometer (Thermo Fisher Scientific). The peptide samples were injected onto a capillary column (PIC OFRIT ^® with 10 μπι tip opening/ 75 μιτι diameter, New Objective, PF360-75-10-N-5) packed in- house with 20 cm C18 silica material (1.9 μπι REPROSIL-PUR ^® CI 8-AQ medium, Dr. Maisch GmbH, rl 19.aq). The UHPLC setup was connected with a custom-fit microadapting tee (360 μιη, IDEX Health & Science, UH-753), and capillary columns were heated to 50 °C in column heater sleeves (Phoenix-ST) to reduce backpressure during UHPLC separation. Injected peptides were separated at a flow rate of 200 nL/min with a linear 80 min gradient from 100% solvent A (3% acetonitrile, 0.1% formic acid) to 30% solvent B (90% acetonitrile, 0.1% formic acid), followed by a linear 6 min gradient from 30% solvent B to 90%> solvent B. Each sample was run for 120 minutes, including sample loading and column equilibration times. The Q EXACTIVE™ instrument was operated in the data-dependent mode acquiring high-energy collisional dissociation (HCD) MS/MS scans (R=17,500) after each MSI scan (R=70,000) on the 12 top most abundant ions using an MSI ion target of 3x 106 ions and an MS2 target of 5x104 ions. The maximum ion time utilized for the MS/MS scans was 120 ms; the HCD-normalized collision energy was set to 27; the dynamic exclusion time was set to 20s, and the peptide match and isotope exclusion functions were enabled. Quantification and identification of peptides and proteins

All mass spectra were processed using the Spectrum Mill software package v4.1 beta (Agilent Technologies) which includes modules developed by Applicants for isobaric tags for relative and absolute quantification (iTRAQ)-based quantification. Precursor ion quantification was done using extracted ion chromatograms (XIC s) for each precursor ion. The peak area for the XIC of each precursor ion subjected to MS/MS was calculated automatically by the Spectrum Mill software in the intervening high-resolution MS 1 scans of the liquid chromatography (LQ-MS/MS runs using narrow windows around each individual member of the isotope cluster. Peak widths in both the time and m/z domains were dynamically determined based on MS scan resolution, precursor charge and m/z, subject to quality metrics on the relative distribution of the peaks in the isotope cluster vs theoretical. Similar MS/MS spectra acquired on the same precursor m/z in the same dissociation mode within +/- 60 seconds were merged. MS/MS spectra with precursor charge >7 and poor quality MS/MS spectra, which failed the quality filter by not having a sequence tag length > 1 (i.e., minimum of 3 masses separated by the in-chain mass of an amino acid) were excluded from searching.

For peptide identification MS/MS spectra were searched against human Universal Protein Resource (Uniprot) database to which a set of common laboratory contaminant proteins was appended. Search parameters included: ESI-Q EXACTIVE™-HCD scoring parameters, trypsin enzyme specificity with a maximum of two missed cleavages, 40% minimum matched peak intensity, +/- 20 ppm precursor mass tolerance, +/- 20 ppm product mass tolerance, and carbamidomethylation of cysteines and iTRAQ labeling of lysines and peptide n-termini as fixed modifications. Allowed variable modifications were oxidation of methionine, N-terminal acetylation, Pyroglutamic acid (N- termQ),Deamidated (N),Pyro Carbamidomethyl Cys (N-termC),with a precursor MH+ shift range of - 18 to 64 Da. Identities interpreted for individual spectra were automatically designated as valid by optimizing score and delta rankl-rank2 score thresholds separately for each precursor charge state in each liquid chromatography (LC)-MS/MS while allowing a maximum target-decoy-based false- discovery rate (FDR) of 1.0% at the spe ctrum level.

In calculating scores at the protein level and reporting the identified proteins, redundancy is addressed in the following manner: the protein score is the sum of the scores of distinct peptides. A distinct peptide is the single highest scoring instance of a peptide detected through an MS/MS spectrum. MS/MS spectra for a particular peptide may have been recorded multiple times, (i.e. as different precursor charge states, isolated from adjacent SCX fractions, modified by oxidation of Met) but are still counted as a single distinct peptide. When a peptide sequence >8 residues long is contained in multiple protein entries in the sequence database, the proteins are grouped together and the highest scoring one and its accession number are reported. In some cases when the protein sequences are grouped in this manner there are distinct peptides which uniquely represent a lower scoring member of the group (isoforms or family members). Each of these instances spawns a subgroup and multiple subgroups are reported and counted towards the total number of proteins. iTRAQ ratios were obtained from the protein-comparisons export table in Spectrum Mill. To obtain iTRAQ protein ratios the median was calculated over all distinct peptides assigned to a protein subgroup in each replicate. To assign interacting proteins the Limma package in the R environment was used to calculate moderated t-test p, as described previously and added Blandt-Altman testing to filter out proteins for which the CI for reproducibility was below 95% (Udeshi et al., Mol Cell Proteomics 1 1, 148-159, 2012).

Validation of DNMDP-induced PDE3A protein interactions using immunoprecipitation and immunob lotting

HeLa cells were transfected with ORF overexpression constructs expressing V5 -tagged

SIRT7, V5-tagged SLFN12, or V5-tagged GFP. ORF expression constructs were obtained from the TRC (clone IDs: TRCN0000468231, TRCN0000476272, ccsbBroad304_99997). At 72 hours post transfection, cells were treated with 10 μΜ DNMDP or trequinsin for 4 hours followed by lysis using the ModRipa lysis buffer and immunoprecipitation of PDE3A. For each condition, 2 mg total protein lysate was incubated with 1 μg of anti-PDE3A antibody at 4° C overnight, after which 7.5 μΐ each of Protein A- and Protein G- Dynabeads (Life Technologies 1000 ID and 10003D) were added and incubated for another 1 hour. Beads were washed and bound proteins were eluted with 30 μΐ of LDS PAGE gel loading buffer. Input (~60 μg total protein lysate) and IP products were resolved on 4-12% Tris-Glycine PAGE gels and immunoblotted with an anti-V5 antibody (Life Technologies R96205, 1 :5000), the Bethyl anti-PDE3A antibody (1 : 1000), and secondary antibodies from LiCOR

Biosciences (Cat.# 926-32210 and 926068021 , each at 1 :10,000). Blots were washed and imaged using a LiCOR Odyssey infrared imager.

Knockdown ofSLFN12 expression using shRNA and testing for drug sensitivity

Constructs expressing shRNAs targeting SLFN12, or the control vector, were packaged into lentiviruses and delivered into HeLa cells by viral transduction. Three S N72-targeting shRNAs were used, all of which were obtained from the TRC (ClonelDs: TRCN0000152141 and

TRCN0000153520 ). Infected cells were selected using 1 μ§/πι1 puromycin for 3 days and then grown in non-selective media for 3 more days. Cells were then plated into 384-well assay plates and tested for drug sensitivity as described above. Knockdown of SLFN12 was validated by qPCR. Total RNA was extracted using kit reagents (RNeasy Mini Kit (Qiagen #74104) and QIAschredder (Qiagen #79656)). cDNA was generated using kit reagents (Superscript III First-Strand Synthesis System (Life Technologies #18080-051)). qPCR was performed for GAPDH and SLFN12 (Life Technologies Hs00430118_ml) according to the manufacturer's recommendations. SLFN12 expression was normalized to corresponding samples GAPDH ct-values.

Other Embodiments

From the foregoing description, it will be apparent that variations and modifications may be made to the invention described herein to adopt it to various usages and conditions. Such embodiments are also within the scope of the following claims.

The recitation of a listing of elements in any definition of a variable herein includes definitions of that variable as any single element or combination (or subcombination) of listed elements. The recitation of an embodiment herein includes that embodiment as any single embodiment or in combination with any other embodiments or portions thereof. Incorporation by Reference

The ASCII text file submitted herewith via EFS-Web, entitled "167741_011202.txt" created on August [[TBD]], 2016, having a size of [[TBD]] bytes, is hereby incorporated by reference in its entirety.

All patents and publications mentioned in this specification are herein incorporated by reference to the same extent as if each independent patent and publication was specifically and individually indicated to be incorporated by reference. In particular, Lewis et al., "Compounds and Compositions for the Treatment of Cancer," PCT/US2014/023263 (WO 2014/164704) is incorporated by reference in its entirety.