METHODS FOR TREATMENT OR PREVENTION OF LEUKEMIA CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority to US Provisional Appl. No. 62/470,037, filed March 10, 2017, the disclosure of which is incorporated by reference herein in its entirety.

TECHNICAL FIELD

[0002] The present technology relates generally to methods for treating, preventing, and/or ameliorating leukemia in a subject in need thereof. Also disclosed herein are methods for reducing the expression and/or activity of synaptotagmin-binding, cytoplasmic RNA- interacting protein (SYNCRIP; also known as NSAP1 or hnRNPQ1 in humans) to treat, prevent, and/or ameliorate leukemia.

BACKGROUND

[0003] The following description of the background of the present technology is provided simply as an aid in understanding the present technology and is not admitted to describe or constitute prior art to the present technology.

[0004] Acute myeloid leukemia (AML) is a genetically complex and heterogeneous set of diseases characterized by a diverse set of mutations (Lindsley, R.C. & Ebert, B.L., Blood 122, 3741–3748 (2013)). Overall survival of adult patients with AML has only improved modestly in the past 30 years (Maynadié, M. et al., Haematologica 96, 55–61 (2011)).

Leukemia stem cells (LSCs) are a subpopulation characterized by a self-renewal capacity and an ability to recapitulate the phenotypic heterogeneity of the disease. While somatic alterations in genetic and epigenetic mechanisms in leukemogenesis are intensively studied, how post-transcriptional and translational regulation of mRNA/protein expression influences leukemia progression and LSC function remains poorly defined.

SUMMARY OF THE PRESENT TECHNOLOGY

[0005] In one aspect, the present disclosure provides a method for treating or preventing AML in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of at least one SYNCRIP-specific inhibitory nucleic acid that inhibits synaptotagmin-binding, cytoplasmic RNA-interacting protein (SYNCRIP) expression levels or activity in the subject. The AML may be T-cell acute lymphoblastic leukemia or B-cell acute lymphoblastic leukemia. [0006] In some embodiments, the at least one SYNCRIP-specific inhibitory nucleic acid comprises a nucleic acid sequence selected from the group consisting of: SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, and any complement thereof. The at least one SYNCRIP-specific inhibitory nucleic acid may be a siRNA, a shRNA, an antisense oligonucleotide, or a sgRNA.

[0007] Additionally or alternatively, in some embodiments of the methods of the present technology, the subject displays elevated expression levels of SYNCRIP protein in leukemic cells prior to treatment. In certain embodiments, treatment with the at least one SYNCRIP- specific inhibitory nucleic acid results in a decrease in SYNCRIP and/or HOXA9 levels in the subject compared to that observed prior to treatment.

[0008] In some embodiments of the methods of the present technology, the subject has been diagnosed as having AML. Signs or symptoms of AML may comprise one or more of leukemic cell proliferation, enlarged lymph nodes, anemia, neutropenia, leukopenia, leukostasis, chloroma, granulocytic sarcoma, myeloid sarcoma, fatigue, weakness, dizziness, chills, headaches, shortness of breath, thrombocytopenia, excess bruising and bleeding, frequent or severe nosebleeds, bleeding gums, gum pain and swelling, headache, weakness in one side of the body, slurred speech, confusion, sleepiness, blurry vision, vision loss, deep venous thrombosis (DVT), pulmonary embolism, bone or joint pain, swelling in the abdomen, seizures, vomiting, facial numbness, defects in balance, weight loss, fever, night sweats, and loss of appetite.

[0009] In any of the above embodiments of the methods disclosed herein, the subject may harbor one or more point mutations in NRAS, DNMT3A, FLT3, KIT, IDH1, IDH2, CEBPA and NPM1 and/or one or more gene fusions selected from the group consisting of CBFB- MYH11, DEK-NUP214, MLL-MLLT3, PML-RARA, RBM15-MKL1, RPN1-EVI1 and RUNX1- RUNX1T1. In certain embodiments, the subject is human.

[0010] Additionally or alternatively, in some embodiments of the methods of the present technology, the at least one SYNCRIP-specific inhibitory nucleic acid is administered orally, topically, intranasally, systemically, intravenously, subcutaneously, intraperitoneally, intradermally, intraocularly, iontophoretically, transmucosally, or intramuscularly. In some embodiments, the at least one SYNCRIP-specific inhibitory nucleic acid is administered daily for 6 weeks or more. In other embodiments, the at least one SYNCRIP-specific inhibitory nucleic acid is administered daily for 12 weeks or more. [0011] Additionally or alternatively, in some embodiments, the methods further comprise separately, sequentially or simultaneously administering one or more additional therapeutic agents to the subject. Examples of additional therapeutic agents include cyclophosphamide, fluorouracil (or 5-fluorouracil or 5-FU), methotrexate, edatrexate (10-ethyl-10-deaza- aminopterin), thiotepa, carboplatin, cisplatin, taxanes, paclitaxel, protein-bound paclitaxel, docetaxel, vinorelbine, tamoxifen, raloxifene, toremifene, fulvestrant, gemcitabine, irinotecan, ixabepilone, temozolmide, topotecan, vincristine, vinblastine, eribulin,

mutamycin, capecitabine, anastrozole, exemestane, letrozole, leuprolide, abarelix, buserlin, goserelin, megestrol acetate, risedronate, pamidronate, ibandronate, alendronate, denosumab, zoledronate, trastuzumab, tykerb, anthracyclines (e.g., daunorubicin and doxorubicin), cladribine, midostaurin, bevacizumab, oxaliplatin, melphalan, etoposide, mechlorethamine, bleomycin, microtubule poisons, annonaceous acetogenins, chlorambucil, ifosfamide, streptozocin, carmustine, lomustine, busulfan, dacarbazine, temozolomide, altretamine, 6- mercaptopurine (6-MP), cytarabine, floxuridine, fludarabine, hydroxyurea, pemetrexed, epirubicin, idarubicin, SN-38, ARC, NPC, campothecin, 9-nitrocamptothecin, 9- aminocamptothecin, rubifen, gimatecan, diflomotecan, BN80927, DX-8951f, MAG-CPT, amsacnne, etoposide phosphate, teniposide, azacitidine (Vidaza), decitabine, accatin III, 10- deacetyltaxol, 7-xylosyl-10-deacetyltaxol, cephalomannine, 10-deacetyl-7-epitaxol, 7- epitaxol, 10-deacetylbaccatin III, 10-deacetyl cephalomannine, streptozotocin, nimustine, ranimustine, bendamustine, uramustine, estramustine, mannosulfan, camptothecin, exatecan, lurtotecan, lamellarin D9-aminocamptothecin, amsacrine, ellipticines, aurintricarboxylic acid, HU-331, or combinations thereof.

[0012] In another aspect, the present disclosure provides a method for inhibiting leukemic cell proliferation in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of an SYNCRIP-specific inhibitory nucleic acid, wherein the subject suffers from a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP.

[0013] Also disclosed herein are methods for monitoring the therapeutic efficacy of an SYNCRIP-specific inhibitory nucleic acid that targets SYNCRIP expression and/or activity in a subject diagnosed with AML comprising: (a) detecting SYNCRIP protein levels in a test sample obtained from the subject after the subject has been administered the SYNCRIP- specific inhibitory nucleic acid; and (b) determining that the SYNCRIP-specific inhibitory nucleic acid is effective when the SYNCRIP protein levels in the test sample are reduced compared to that observed in a control sample obtained from the subject prior to administration of the SYNCRIP-specific inhibitory nucleic acid. The SYNCRIP-specific inhibitory nucleic acid may be a siRNA, a shRNA, an antisense oligonucleotide, or a sgRNA. The test sample may be tissues, cells or biological fluids (blood, plasma, saliva, urine, serum etc.) present within a subject. In certain embodiments, the method further comprises detecting HOXA9 levels in the subject. Additionally or alternatively, in some embodiments, the SYNCRIP-specific inhibitory nucleic acid comprises a nucleic acid sequence selected from the group consisting of: SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, and SEQ ID NO: 21, and any complement thereof.

[0014] Also provided herein are kits comprising one or more SYNCRIP-specific inhibitory nucleic acids comprising a nucleic acid sequence selected from the group consisting of SEQ ID NOs: 1-2, 18-21, and any complement thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1(A) shows a Venn diagram showing mass spectrometry analysis of Flag- MSI2 immunoprecipitation in K562 cells transduced with FLAG-MSI2 or empty vector.

[0016] Figure 1(B) shows a summary of the pooled shRNA screening strategy from primary leukemia cells.

[0017] Figure 1(C) shows a Waterfall plot depicting normalized depletion levels of all shRNAs in bone marrow (BM), generated from the data in Figure 15. Top candidate genes included SYNCRIP, Caprin1, Dyrk2, Hnrnpr, Cct3, Mybbp1a, and Hnrnpa3.

[0018] Figure 1(D) shows a Venn diagram showing score of 24 hits in bone marrow and spleen samples.

[0019] Figure 1(E) shows a heatmap depicting normalized depletion levels of all shRNAs targeting top 24 genes scored both in bone marrow (BM) and spleen (SP), generated from the data in Figure 15 and Figure 16.

[0020] Figure 1(F) shows a pie chart showing the scoring percentage of each screening pool in comparison to the predicted score based on pool representation.

[0021] Figure 1(G) shows Gene Ontology (GO) analysis of the top 24 genes scored in in vivo screen. [0022] Figure 1(H) shows log ₂ fold depletion in the bone marrow (BM) and spleen (SP) of all the shRNAs against seven candidate genes in the pooled shRNA screen. error bars, s.e.m **p < 0.01 two tailed t test.

[0023] Figure 1(I) shows colony formation was impaired in KD leukemia cells. The number of colonies formed was normalized to that of control MLL-AF9 leukemia cells or control normal c-kit enriched bone marrow cells. n=4 independent experiments; error bars, s.e.m. P value calculated by two tailed t test.

[0024] Figure 2(A) shows the effects of SYNCRIP Knock Down (KD) in mouse MLL- AF9 leukemia cells.

[0025] Figure 2(B) shows that shRNA-mediated depletion of SYNCRIP promoted myeloid differentiation of leukemia cells. Representative FACS plot of control and

SYNCRIP Knock Down (KD) leukemia cells.

[0026] Figure 2(C) shows the quantitative summary of FACS analysis of Gr-1 and Mac-1 expression in control and SYNCRIP Knock Down (KD) leukemia cells 3 days and 4 days post transduction, n=3 and n=5, respectively, independent experiments; error bars, s.e.m. ** p<0.01, * p<0.05 two sided t test.

[0027] Figure 2(D) shows Giemsa staining of control and SYNCRIP Knock Down (KD) leukemia cells at 4 days post transduction. Original magnification 63X, 1.4 NA Scale bars: 10 µM.

[0028] Figure 2(E) shows Annexin-V expression assessed by flow cytometry 5 days post transduction. n=3 independent experiments; error bars, s.e.m. ** p<0.01, * p<0.05 two tailed t test.

[0029] Figure 2(F) shows Kaplan Meier analysis of leukemia-free survival outcomes after injection of SYNCRIP depleted or control cells into sub-lethally irradiated mice. n=10 for each group, Mantel-Cox test *** p<0.001, **** p<0.0001.

[0030] Figure 2(G) shows the reduction of SYNCRIP expression in MLL-AF9 leukemia cells with mutant NRAS expressing a rtTA (RN2 cells) and transduced with tet(O)-inducible Cas9-GFP expressing guide RNAs specific for SYNCRIP (gRNA1 and gRNA3) or Cas9-GFP empty gRNA (Cas9-EV). [0031] Figure 2(H) shows cells from Figure 2(g) plated and counted for cellular growth control and two gRNAs. n=3 independent experiments; error bars, s.e.m. * p<0.05 two tailed t test.

[0032] Figure 2(I) shows cells from 2(G) were plated into methylcellulose colony assay. n=4 independent experiments; error bars, s.e.m. * p<0.05 two tailed t test.

[0033] Figure 2(J) shows Kaplan Meier analysis of leukemia-free survival outcomes after injection of RN2 cells overexpressing SYNCRIP or carrying control- empty vector into sub- lethally irradiated mice n=10 for each group, Mantel-Cox test *** p<0.001.

[0034] Figure 2(K) shows that overexpression of SYNCRIP rescued colony forming ability of RN2 cells depleted of endogenous SYNCRIP. n=4 independent experiments; error bars, s.e.m. ** p<0.01 two tailed t test.

[0035] Figure 2(L) shows the quantitative summary of FACS analysis of Gr-1 and Mac-1 expression in Cas9-EV and SYNCRIP-gRNAs transduced leukemia cells in Figure 2(K), n=3 independent experiments; error bars, s.e.m. *p<0.05, ** p<0.01 two tailed t test.

[0036] Figure 3(A) shows the Syncrip locus and CRISPR/Cas9 targeting strategy for generation of (KO).

[0037] Figure 3(B) shows the experimental scheme for generation of hematopoietic Syncrip-CR-KO using CRISPR/Cas9 approach and bone marrow transplantation of fetal liver cells.

[0038] Figure 3(C) shows FACS analysis of hematopoietic stem and progenitor cells in WT and Syncrip-CR-KO fetal livers.

[0039] Figure 3(D) shows FACS histograms of SYNCRIP intracellular staining of CD45.2 positive bone marrow cells isolated from WT and Syncrip-CR-KO recipient mice.

[0040] Figure 3(E) shows immunoblot analysis of CD45.2 positive bone marrow cells isolated from WT and Syncrip-CR-KO recipient mice.

[0041] Figure 3(F) shows quantitative summary of FACS analysis of hematopoietic stem and progenitor compartments in WT and Syncrip-CR-KO recipient mice. LIVE: total bone marrow cells; LSK: Lin-Sca1 ⁺ Kit- cells; PROG: Progenitor cells; GMP: Granulocyte

Macrophage progenitor; CMP: Common Myeloid progenitor; MEP: Megakaryocyte- Erythrocyte progenitor. WT n=9; CR-KO n=5. [0042] Figure 3(G) shows an experimental scheme for LSK-derived MLL-AF9 leukemia transplantation model and secondary bone marrow transplantation.

[0043] Figure 3(H) shows the quantitative summary of FACS analysis of hematopoietic stem and progenitor compartments in WT and Syncrip-CR-KO secondary recipient mice. WT n=6; CR-KO n=6, error bars, s.e.m. *p<0.05 two tailed t test.

[0044] Figure 3(I) shows the quantitative summary of relative median fluorescence intensity (MFI) analysis of SYNCRIP intracellular staining of engrafted CD45.2 cells in WT and Syncrip-CR-KO secondary recipient mice. WT n=4; CR-KO n=7 error bars, s.e.m.

***p<0.001 two tailed t test.

[0045] Figure 3(J) shows Kaplan Meier analysis of leukemia free survival outcomes after injection of MLL-AF9 transformed WT and Syncrip-CR-KO cells into lethally irradiated mice WT n=8, Syncrip-CR-KO n=12; Mantel-Cox test ** p<0.01.

[0046] Figure 3(K) shows the quantitative summary of relative MFI analysis of

SYNCRIP intracellular staining of GFP positive and GFP positive c-kit high cells from mice succumbed to leukemia in WT vs. Syncrip -CR-KO. WT n=5; CR-KO n=5.

[0047] Figure 4(A) shows that SYNCRIP is upregulated in AML patient samples. The graph shows the log ₂ expression of SYNCRIP from transcriptional profiling of bone marrow cells from patients with various subtypes of AML and of the normal hematopoietic stem/progenitor cells (HSPCs) from healthy donors. AML n=142; AML inv(16)/t(16;16) n=27; AML t(11q23)/MLL n=38; AML ETO n=39; APL n=37; HSC n=8; HPC n=4; Prog n=9; B-cells n=5; Mono n=14; T cell CD4/CD8 n=10. error bars, s.e.m. **** p<0.0001 two tailed t test. (Hemaexplorer data of SYNCRIP probe 209024_s_at from the U133 Plus 2.0 array).

[0048] Figure 4(B) shows high expression levels of SYNCRIP in multiple human AML cell lines. Immunoblot of various myeloid leukemia cell lines are compared to cord blood derived CD34 ⁺ cells.

[0049] Figure 4(C) shows SYNCRIP expression in primary AML patient samples. Actin serves as a loading control.

[0050] Figure 4(D) shows cell proliferation in MOLM13 cell line after transduction with lentivirus expressing control or SYNCRIP-specific shRNAs. n=3 independent experiments per cell line; error bars, s.e.m. ***p<0.001 two tailed t test. [0051] Figure 4(E) shows cell proliferation in NOMO-1 cell line after transduction with lentivirus expressing control or SYNCRIP-specific shRNAs. n=3 independent experiments per cell line; error bars, s.e.m. ***p<0.001 two tailed t test.

[0052] Figure 4(F) shows cell proliferation in KASUMI-1 cell line after transduction with lentivirus expressing control or SYNCRIP-specific shRNAs. n=3 independent experiments per cell line; error bars, s.e.m. ***p<0.001 two tailed t test.

[0053] Figure 4(G) shows cell proliferation in NB4 cell line after transduction with lentivirus expressing control or SYNCRIP-specific shRNAs. n=3 independent experiments per cell line; error bars, s.e.m. ***p<0.001 two tailed t test.

[0054] Figure 4(H) shows Annexin-V expression assessed by flow cytometry 24 hours post puromycin selection. n=3 independent experiments per cell line; error bars, s.e.m. * p<0.05, **p<0.001 two tailed t test.

[0055] Figure 5(A) shows a gene expression heat map of the top 191 upregulated and downregulated genes from RNA-sequencing analysis of MLL-AF9 leukemia cells transduced with control and shRNAs against SYNCRIP. n=3 biological replicates.

[0056] Figure 5(B) shows Gene Set Enrichment Analysis (GSEA) results showing that the gene expression signature for genes enriched in hematopoietic stem cells was upregulated in SYNCRIP-KD cells.

[0057] Figure 5(C) shows GSEA results showing that the gene expression signature for genes enriched in leukemic stem cells was upregulated in SYNCRIP-KD cells.

[0058] Figure 5(D) shows GSEA results showing that the gene expression signature for genes enriched in myeloid development program was upregulated in SYNCRIP-KD cells.

[0059] Figure 5(E) shows GSEA results showing that the gene expression signature for MLL-AF9 directed target genes was downregulated in SYNCRIP-KD cells.

[0060] Figure 5(F) shows GSEA results showing that the gene expression signature for MLL-AF9 directed target genes was downregulated in SYNCRIP-KD cells.

[0061] Figure 5(G) shows GSEA results showing that the gene expression signature for HOXA9-MEIS1 target genes was downregulated in SYNCRIP-KD cells.

[0062] Figure 5(H) shows enrichment of MSI2 target genes among SYNCRIP regulated genes. [0063] Figure 5(I) shows enrichment of MSI2 target genes among SYNCRIP regulated genes.

[0064] Figure 6(A) shows immunoprecipitation of endogenous MSI2 and SYNCRIP in human myeloid leukemia K562 cells overexpressing MSI2. Lysates of K562 cells overexpressing MSI2 were incubated with RNase and immunoprecipitated.

[0065] Figure 6(B) shows immunoprecipitation of SYNCRIP with IgG or SYNCRIP antibody in either wild-type (WT) mouse RN2 MLL-AF9 leukemia cells or human SYNCRIP overexpressing (OV) mouse RN2 MLL-AF9 leukemia cells. n=4 independent experiments; error bars, s.e.m. * p<0.05, **p<0.001 two tailed t test.

[0066] Figure 6(C) shows downregulation of HOXA9, c-MYC and IKZF2 protein levels upon SYNCRIP knock down in RN2 cells 24 hours post induction with tetracycline with as assessed by immunoblot analysis.

[0067] Figure 6(D) shows expression levels of HOXA9 and c-MYC upon SYNCRIP-KD in human MOLM13 leukemia cells 3 and 4 days post transduction with viruses expressing control shRNA and SYNCRIP-shRNAs together with GFP as assessed by immunoblot analysis.

[0068] Figure 6(E) shows protein expression levels of SYNCRIP, HOXA9 and c-MYC in AHA-pull down fraction, input and flow through fraction as assessed by immunoblot analysis. AHA incorporation into newly synthesized HOXA9 (but not c-MYC) proteins was reduced in SYNCRIP-KD cells. Streptavidin-HRP, Ponceau staining and Actin serve as control for total protein input and loading control.

[0069] Figure 6(F) shows representative histogram analysis of OP-Puro incorporation in control and SYNCRIP-KD MOLM13 cells (shRNA#1 and shRNA#2) at 3 days post transduction with viruses expressing control shRNA and SYNCRIP-shRNAs.

[0070] Figure 6(G) shows quantitative summary of relative OP-Puro incorporation in cells described in Figure 6(F). CHX-treated cells were used as negative control (n=3). Cells without OP-Puro incorporation served as staining control. n=4 independent experiments; error bars, s.e.m. *p<0.05, **p<0.001, ***p<0.0001 two tailed t test.

[0071] Figure 7(A) shows colony formation was rescued in dsRed SYNCRIP-KD leukemia cells with MSI2 overexpression. n=3 independent experiments. [0072] Figure 7(B) shows colony formation was rescued in dsRed SYNCRIP-KD leukemia cells with HOXA9-CDS overexpression. n=4 independent experiments.

[0073] Figure 7(C) shows depletion of SYNCRIP expression and expression of HOXA9 in dsRed SYNCRIP-KD leukemia cells that overexpress HOXA9-CDS as assessed by immunoblot analysis 4 days after transduction.

[0074] Figure 7(D) shows rescue of cell growth in SYNCRIP-KD human MOLM13 leukemia cells with HOXA9 overexpression. n=3 independent experiments.

[0075] Figure 7(E) shows depletion of SYNCRIP expression and expression of HOXA9 in SYNCRIP-KD human MOLM13 leukemia cells that overexpress HOXA9-CDS as assessed by immunoblot analysis 4 days after transduction.

[0076] Figure 7(F) shows quantitative summary of percentage of engrafted hCD45 ⁺ GFP ⁺ cells in recipient mice transplanted with primary AML patient cells transduced with control shRNA or shRNAs against SYNCRIP (shRNA#1 and shRNA#2) at week 10 and week 16 post transplantation. n=5 for each group.

[0077] Figure 7(G) shows depletion of SYNCRIP expression in primary AML patient cells and downregulation of HOXA9 expression as assessed by immunoblots analysis. All data: error bars, s.e.m. ns:*p<0.05, **p<0.001, ***p<0.0001 two tailed t test.

[0078] Figure 7(H) shows a schematic depicting the dominant function of SYNCRIP when its expression is elevated in LSCs in comparison to normal HSCs. In LSCs, SYNCRIP and MSI2 binds and increases expression of the mRNA transcripts associated with the MLL self-renewal program, including Hoxa9 thus driving the LSC program instead of normal hematopoietic development.

[0079] Figure 8(A) shows Coomassie blue staining of Flag-MSI2 immunoprecipitated complexes.

[0080] Figure 8(B) shows GO analysis of MSI2 interacting proteins.

[0081] Figure 8(C) shows the proportion of total read counts sequenced per pool.

cntl=Control pool.

[0082] Figure 8(D) shows a scatterplot depicting concordance of shRNA abundance (log ₂ normalized read counts) between each one of the replicates against their respective groups (median of log ₂ normalized read counts). [0083] Figure 8(E) shows number of control hairpins represented with a minimum arbitrary threshold (normalized counts>100).

[0084] Figure 8(F) shows a Waterfall plot depicting normalized depletion levels of all shRNAs in spleen (SP), generated from the data in Figure 16. Top candidate genes included SYNCRIP, Caprin1, Dyrk2, Hnrnpr, Cct3, Mybbp1a, and Hnrnpa3, and control shRNAs include RFP, lacZ and luciferase.

[0085] Figure 8(G) shows summary of seven candidate genes.

[0086] Figure 8(H) shows validation of efficient knockdown of target genes in mouse MLL-AF9 leukemia cells. Cells were selected under puromycin treatment for 48 hours prior to qRT-PCR assay. β-Actin serves as housekeeping gene control. All data represent the mean + s.e.m of at least three independent experiments. * p < 0.05, **p < 0.01, *** p<0.001 by two tailed t test.

[0087] Figure 9(A) shows knockdown of SYNCRIP in mouse MLL-AF9 leukemia cells. MLL-AF9 cells were transduced with lentiviruses expressing control shRNA (shRNA against Luciferase) or shRNAs directed against Syncrip (shRNA-1 and shRNA-2). Cells were selected under puromycin treatment for 24 hours prior to immunoblotting. Cells were harvested and assayed 3 days post viral transduction. Actin serves as loading control.

[0088] Figure 9(B) shows shRNA depletion of SYNCRIP promoted myeloid

differentiation of leukemia cells. Myeloid differentiation status was assayed by FACS analysis of F-480 and CD115 expression at 4 days post transduction. A representative FACS plot is shown for control and SYNCRIP-KD leukemia cells.

[0089] Figure 9(C) shows quantitative summary of FACS analysis of F-480 and CD115 expression in control and SYNCRIP-KD leukemia cells 3 days and 4 days post transduction.

[0090] Figure 9(D) shows quantitative summary of FACS analysis of percentage of c- kit ^high cells in control and SYNCRIP-KD leukemia cells 4 days post transduction.

[0091] Figure 9(E) shows increased apoptosis was not observed in SYNCRIP-KD leukemia cells at 3 days and 4 days post transduction. Quantitative summary of Annexin-V assessed by flow cytometry.

[0092] Figure 9(F) shows Annexin-V expression assessed by flow cytometry 5 days post transduction of control and SYNCRIP-KD leukemia cells. A representative FACS analysis of Figure 2(E) is shown. [0093] Figure 9(G) shows quantitative qPCR demonstrating KD of SYNCRIP in mouse AML1-ETO9a driven leukemia cells. Cells were selected under puromycin treatment for 48 hours prior to qRT-PCR. β-Actin serves as housekeeping gene control.

[0094] Figure 9(H) shows cells from Figure 9(G) were plated into methylcellulose and scored for number of colonies (average of three independent experiments).

[0095] Figure 9(I) shows the assessment of disease burden, including spleen weight and liver weight of recipient mice in Figure 2(F).

[0096] Figure 9(J) shows SYNCRIP protein expression in bone marrow (as assessed by immunoblot analysis) of mice succumbed to disease in Figure 2(F) and Figure 9(I). Mice injected with SYNCRIP-KD1 with reduced disease burden (group 1) maintained better SYNCRIP knockdown level compared to mice (group 2), which manifested similar disease to control group.

[0097] Figure 9(K) shows quantitative qPCR showing KD of Syncrip assayed by primers designed for specific gRNA targeting regions (gRNA specific primers) in RN2 cells that were transduced for 24 hours with CRISPR/Cas9 containing tet-inducible guide RNAs specific for Syncrip (gRNA1-3) in comparison to control- Cas9-EV 24 hours.

[0098] Figure 9(L) shows quantitative summary of FACS analysis of the percentage of Gr-1 ⁺ and Mac-1 ⁺ positive cells in Cas9-EV and Syncrip-gRNAs transduced leukemia cells shown in Figure 2(I).

[0099] Figure 9(M) shows the quantitative summary of FACS analysis of the percentage of c-kit ^high cells in Cas9-EV and SYNCRIP-gRNAs transduced leukemia cells shown in Figure 2(I).

[00100] Figure 9(N) shows immunoblot analysis of RN2 cells overexpressing different isoforms of SYNCRIP corresponding to proteins of 527 amino acids (aa), 562 aa and 623 aa. The SYNCRIP 562-aa isoform was the predominantly expressed isoform in leukemia cells. Actin serves as loading control.

[00101] Figure 9(O) shows that SYNCRIP overexpression in RN2 cells promotes colony formation (average of three independent experiments).

[00102] Figure 9(P) shows mouse-Syncrip expression as assayed by qPCR using gRNA specific primers, and human-SYNCRIP expression for Figure 2(K). [00103] Figure 9(Q) shows immunoblot analysis of RN2 cells overexpressing SYNCRIP or harboring control (empty vector (EV)) that were transduced for 24 hours with

CRISPR/Cas9 containing tet-inducible gRNA1 and gRNA3 constructs or Cas9-EV in Figure 2(J). All data represent the mean + s.e.m of at least three independent experiments. * p < 0.05, **p < 0.01, *** p<0.001 by two tailed t test.

[00104] Figure 10(A) shows representative PCR analysis for genotyping of Syncrip deletion in fetal liver cells.

[00105] Figure 10(B) shows a quantitative summary of FACS analysis of hematopoietic stem and progenitor cells in the WT and Syncrip-CR-KO fetal livers in Figure 3(C) (WT n=7; CR-KO n=7).

[00106] Figure 10(C) shows a quantitative summary of the number of all colony types formed by WT and Syncrip-CR-KO fetal liver cells (average of 6 biological samples). BFU- E: burst-forming unit-erythroid, M: macrophage, G: granulocyte, GM: granulocyte, macrophage, GEMM: granulocyte, erythroid, macrophage, megakaryocyte.

[00107] Figure 10(D) shows the assessment of disease burden, including spleen weight and liver weight of recipient mice shown in Figure 3(J). * p < 0.05 by two tailed t test.

[00108] Figure 11(A) shows a graph of the log ₂ expression of SYNCRIP from transcript profiling of bone marrow cells from patients with various types of hematological

malignancies including ALLs, B-ALLs, CLL, MDS, CML and subtypes of AML and of healthy donors. Hypodiploid B-ALL, n = 40; ALL with t(1;19), n = 36; ALL with

t(12;21), n = 58; B-ALL with t(8;14), n = 13; c-/pre-B-ALL without t(9;22), n = 237; c-/pre- B-ALL with t(9;22), n = 122; pro-B-ALL with t(11q23)/MLL, n = 70; CLL, n = 448; T- ALL, n = 174; MDS, n = 206; CML, n = 76; complex AML, n = 48; AML with inv(16), n = 28; AML MLL, n = 38; AML with a normal karyotype, n = 351; AML with t(15;17), n = 37; AML with t(8;21), n = 40; healthy donors, n = 73. **p < 0.01, ***p < 0.001, ****p < 0.0001, Student’s t test. (Hemaexplorer data for SYNCRIP probe 209024_s_at from the U133 and U133 Plus 2.0 arrays).

[00109] Figure 11(B) shows qPCR of SYNCRIP mRNA levels in multiple human AML cell lines and normal cord blood derived CD34 ⁺ cells (CB-CD34 ⁺ ). β-actin served as a housekeeping gene control. Relative mRNA level was normalized to SYNCRIP mRNA in CB-CD34 ⁺ cells. [00110] Figure 11(C) shows SYNCRIP knockdown in MOLM13 AML cell line as assessed by immunoblot analysis.

[00111] Figure 11(D) shows SYNCRIP knockdown in NOMO-1 AML cell line as assessed by immunoblot analysis.

[00112] Figure 11(E) shows SYNCRIP knockdown in KASUMI AML cell line as assessed by immunoblot analysis.

[00113] Figure 11(F) shows SYNCRIP knockdown in NB4 AML cell line as assessed by immunoblot analysis.

[00114] Figure 11(G) shows a quantitative summary of CD14 ^high and CD13 ^high cells and CD14 and CD13 MFI in MOLM13, NB4 and NOMO-1 cells transduced with control shRNA or shRNAs against SYNCRIP (shRNA#1 and shRNA#2) 4 days post transduction.

[00115] Figure 11(H) shows representative FACS plots of cells in Figure 4(H). All data represent the mean + s.e.m of at least three independent experiments. * p < 0.05, **p < 0.01, *** p<0.001 by two tailed t test.

[00116] Figure 12(A) shows plots representing the distribution of mean normalized counts of KD1 correlating with normalized mean counts of KD2 from RNA-sequencing data shown in Figure 5(A).

[00117] Figure 12(B) shows normalized read counts of Syncrip, HoxA9, c-Myc, Ikzf2 and Meis1 from RNA-sequencing data shown in Figure 5(A).

[00118] Figure 12(C) shows log ₂ mRNA expression levels of MSI2 in patients with high vs. low SYNCRIP mRNA expression in AML patients reported in Figure 4(A)

(high SYNCRIP was defined as individuals with a value greater than the average + 1 s.d. while low SYNCRIP was defined as individuals with a value greater than the average– 1 s.d.). * p < 0.05, **p < 0.01, *** p<0.001 by two tailed t test.

[00119] Figure 12(D) shows log ₂ mRNA expression levels of target genes upregulated by HOXA9-MEIS in patients with high vs. low SYNCRIP mRNA expression in AML patients reported in Figure 4(A) (high SYNCRIP was defined as individuals with a value greater than the average + 1 s.d. while low SYNCRIP was defined as individuals with a value greater than the average– 1 s.d.). * p < 0.05, **p < 0.01, *** p<0.001 by two tailed t test.

[00120] Figure 12(E) shows log ₂ mRNA expression levels of target genes downregulated by HOXA9-MEIS in patients with high vs. low SYNCRIP mRNA expression in AML patients reported in Figure 4(A) (high SYNCRIP was defined as individuals with a value greater than the average + 1 s.d. while low SYNCRIP was defined as individuals with a value greater than the average– 1 s.d.). * p < 0.05, **p < 0.01, *** p<0.001 by two tailed t test.

[00121] Figure 12(F) shows log ₂ mRNA expression levels of IZKF2 in patients with high vs. low SYNCRIP mRNA expression in AML patients reported in Figure 4(A)

(high SYNCRIP was defined as individuals with a value greater than the average + 1 s.d. while low SYNCRIP was defined as individuals with a value greater than the average– 1 s.d.). * p < 0.05, **p < 0.01, *** p<0.001 by two tailed t test.

[00122] Figure 12(G) shows log ₂ mRNA expression levels of c-MYC in patients with high vs. low SYNCRIP mRNA expression in AML patients reported in Figure 4(A)

(high SYNCRIP was defined as individuals with a value greater than the average + 1 s.d. while low SYNCRIP was defined as individuals with a value greater than the average– 1 s.d.). * p < 0.05, **p < 0.01, *** p<0.001 by two tailed t test.

[00123] Figure 13(A) shows MOLM13 human myeloid leukemia cells carrying the MLL- AF9 translocation overexpressing MSI2 were immunoprecipitated for endogenous MSI2 and SYNCRIP.

[00124] Figure 13(B) shows immunoblots showing protein expression of HOXA9, MYC and IKZF2 upon SYNCRIP knockdown in dsRed MLL-AF9 cells 3 and 4 days after transduction. Actin serves as a loading control.

[00125] Figure 13(C) shows immunoblots showing protein expression of HOXA9 and MYC upon SYNCRIP knockdown in MOLM13 cells after 2 days of puromycin selection (4 days after transduction).

[00126] Figure 13(D) shows qPCR measuring the mRNA expression

of Syncrip, Hoxa9, Myc and Ikzf2 in dsRed tertiary MLL-AF9 leukemia cells 3 days after transduction.

[00127] Figure 13(E) shows qPCR measuring the mRNA expression

of Syncrip, Hoxa9, Myc and Ikzf2 in dsRed tertiary MLL-AF9 leukemia cells 4 days after transduction.

[00128] Figure 13(F) shows immunoblots showing protein expression of HOXA9, MYC and SYNCRIP upon MSI2 knockdown in dsRed MLL-AF9 cells at 4 days after transduction. [00129] Figure 13(G) shows qPCR measuring mRNA expression

of Syncrip, Hoxa9, Myc and Ikzf2 upon MSI2 knockdown in dsRed MLL-AF9 cells at 4 days after transduction.

[00130] Figure 13(H) shows qPCR measuring mRNA expression

of Syncrip, Hoxa9, Myc and Ikzf2 in RN2 cells 24 hours after induction.

[00131] Figure 13(I) shows qPCR measuring mRNA expression

of Syncrip, Hoxa9, Myc and Ikzf2 in human MOLM13 leukemia cells 3 days after transduction.

[00132] Figure 13(J) shows qPCR measuring mRNA expression

of Syncrip, Hoxa9, Myc and Ikzf2 in human MOLM13 leukemia cells 4 days after transduction.

[00133] Figure 13(K) shows normalized total RNA levels in dsRed MLL-AF9, RN2 and MOLM13 cells upon SYNCRIP depletion.

[00134] Figure 13(L) shows mRNA stability of Syncrip, Hoxa9, Myc and Ikzf2 in dsRed cells transduced with control and SYNCRIP shRNAs 4 days after transduction.

[00135] Figure 13(M) shows mRNA stability of Syncrip, Hoxa9, Myc and Ikzf2 in RN2 cells expressing Cas9-EV or gRNA1 and gRNA3 targeting Syncrip after 24 hours of doxycycline induction. Actin served as a loading control. β-actin served as a control housekeeping gene. All data represent the means + s.e.m. of at least three independent experiments. *p < 0.05, **p < 0.01, ***p < 0.001, two-tailed t test.

[00136] Figure 14(A) shows qPCR measuring mRNA expression showing that MSI2 overexpression increased the mRNA levels of Hoxa9, Myc and Ikzf2. All data represent the means + s.e.m. of at least three independent replicates. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, two-tailed t test.

[00137] Figure 14(B) shows immunoblots that show depletion of SYNCRIP, and protein expression of HOXA9 for the cells in Figure 14(A). Actin served as a loading control. β- actin served as a control housekeeping gene.

[00138] Figure 14(C) shows that colony formation was rescued in dsRed SYNCRIP-KD leukemia cells overexpressing full-length HOXA9. All data represent the means + s.e.m. of at least three independent replicates. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, two-tailed t test. [00139] Figure 14(D) shows immunoblots that show depletion of SYNCRIP, and protein expression of HOXA9 for the cells in Figure 14(C). Actin served as a loading control. β- actin served as a control housekeeping gene.

[00140] Figure 14(E) shows that colony formation was not rescued in dsRed SYNCRIP- KD leukemia cells overexpressing MYC. All data represent the means + s.e.m. of at least three independent replicates. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, two- tailed t test.

[00141] Figure 14(F) shows immunoblots that show depletion of SYNCRIP, and protein expression of MYC for the cells in Figure 14(E). Actin served as a loading control. β- actin served as a control housekeeping gene.

[00142] Figure 14(G) shows that cell growth was not rescued in MOLM13 SYNCRIP-KD cells overexpressing MYC. All data represent the means + s.e.m. of at least three independent replicates. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, two-tailed t test.

[00143] Figure 14(H) shows immunoblots that show depletion of SYNCRIP, and protein expression of MYC for the cells in Figure 14(G). Actin served as a loading control. β- actin served as a control housekeeping gene.

[00144] Figure 15 shows raw normalized read counts of all target sequences in the in vivo shRNA screen in bone marrow.

[00145] Figure 16 shows raw normalized read counts of all target sequences in the in vivo shRNA screen in spleen.

[00146] Figure 17 shows a list of differentially expressed genes in Syncrip-shRNA leukemia cells with log ₂ (fold change) >1.5.

[00147] Figure 18 shows the nucleic acid sequence of Homo sapiens synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP), transcript variant 7, mRNA (SEQ ID NO: 5).

[00148] Figure 19 shows the nucleic acid sequence of Homo sapiens synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP), transcript variant 6, mRNA (SEQ ID NO: 6). [00149] Figure 20 shows the nucleic acid sequence of Homo sapiens synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP), transcript variant 2, mRNA (SEQ ID NO: 7).

[00150] Figure 21 shows the nucleic acid sequence of Homo sapiens synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP), transcript variant 5, mRNA (SEQ ID NO: 8).

[00151] Figure 22 shows the nucleic acid sequence of Homo sapiens synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP), transcript variant 1, mRNA (SEQ ID NO: 9).

[00152] Figure 23 shows the nucleic acid sequence of Homo sapiens synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP), transcript variant 3, mRNA (SEQ ID NO: 10).

[00153] Figure 24 shows the nucleic acid sequence of Homo sapiens synaptotagmin binding cytoplasmic RNA interacting protein (SYNCRIP), transcript variant 4, mRNA (SEQ ID NO: 11).

[00154] Figure 25(A) shows the targeting scheme for SYNCRIP conditional knockout mice.

[00155] Figure 25(B) shows the experimental schemes for studying the effects of SYNCRIP depletion in normal hematopoiesis.

[00156] Figure 25(C) shows the experimental schemes for studying the effects of SYNCRIP depletion in leukemia.

DETAILED DESCRIPTION

[00157] It is to be appreciated that certain aspects, modes, embodiments, variations and features of the present methods are described below in various levels of detail in order to provide a substantial understanding of the present technology.

[00158] In practicing the present methods, many conventional techniques in molecular biology, protein biochemistry, cell biology, microbiology and recombinant DNA are used. See, e.g., Sambrook and Russell eds. (2001) Molecular Cloning: A Laboratory Manual, 3rd edition; the series Ausubel et al. eds. (2007) Current Protocols in Molecular Biology; the series Methods in Enzymology (Academic Press, Inc., N.Y.); MacPherson et al. (1991) PCR 1: A Practical Approach (IRL Press at Oxford University Press); MacPherson et al. (1995) PCR 2: A Practical Approach; Harlow and Lane eds. (1999) Antibodies, A Laboratory Manual; Freshney (2005) Culture of Animal Cells: A Manual of Basic Technique, 5th edition; Gait ed. (1984) Oligonucleotide Synthesis; U.S. Patent No.4,683,195; Hames and Higgins eds. (1984) Nucleic Acid Hybridization; Anderson (1999) Nucleic Acid Hybridization; Hames and Higgins eds. (1984) Transcription and Translation; Immobilized Cells and Enzymes (IRL Press (1986)); Perbal (1984) A Practical Guide to Molecular Cloning; Miller and Calos eds. (1987) Gene Transfer Vectors for Mammalian Cells (Cold Spring Harbor Laboratory);

Makrides ed. (2003) Gene Transfer and Expression in Mammalian Cells; Mayer and Walker eds. (1987) Immunochemical Methods in Cell and Molecular Biology (Academic Press, London); and Herzenberg et al. eds (1996) Weir’s Handbook of Experimental Immunology. Definitions

[00159] Unless defined otherwise, all technical and scientific terms used herein generally have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs. As used in this specification and the appended claims, the singular forms“a”,“an” and“the” include plural referents unless the content clearly dictates otherwise. For example, reference to“a cell” includes a combination of two or more cells, and the like. Generally, the nomenclature used herein and the laboratory procedures in cell culture, molecular genetics, organic chemistry, analytical chemistry and nucleic acid chemistry and hybridization described below are those well-known and commonly employed in the art.

[00160] As used herein, the term“about” in reference to a number is generally taken to include numbers that fall within a range of 1%, 5%, or 10% in either direction (greater than or less than) of the number unless otherwise stated or otherwise evident from the context (except where such number would be less than 0% or exceed 100% of a possible value).

[00161] As used herein, the“administration” of an agent or drug to a subject includes any route of introducing or delivering to a subject a compound to perform its intended function. Administration can be carried out by any suitable route, including orally, intranasally, parenterally (intravenously, intramuscularly, intraperitoneally, or subcutaneously), or topically. Administration includes self-administration and the administration by another.

[00162] The terms“complementary” or“complementarity” as used herein with reference to polynucleotides (i.e., a sequence of nucleotides such as an oligonucleotide or a target nucleic acid) refer to the base-pairing rules. The complement of a nucleic acid sequence as used herein refers to an oligonucleotide which, when aligned with the nucleic acid sequence such that the 5' end of one sequence is paired with the 3' end of the other, is in“antiparallel association.” For example, the sequence“5'-A-G-T-3'” is complementary to the sequence “3'-T-C-A-5.” Certain bases not commonly found in naturally-occurring nucleic acids may be included in the nucleic acids described herein. These include, for example, inosine, 7- deazaguanine, Locked Nucleic Acids (LNA), and Peptide Nucleic Acids (PNA).

Complementarity need not be perfect; stable duplexes may contain mismatched base pairs, degenerative, or unmatched bases. Those skilled in the art of nucleic acid technology can determine duplex stability empirically considering a number of variables including, for example, the length of the oligonucleotide, base composition and sequence of the

oligonucleotide, ionic strength and incidence of mismatched base pairs. A complementary sequence can also be an RNA sequence complementary to the DNA sequence or its complementary sequence, and can also be a cDNA.

[00163] As used herein, a "control" is an alternative sample used in an experiment for comparison purpose. A control can be "positive" or "negative." For example, where the purpose of the experiment is to determine a correlation of the efficacy of a therapeutic agent for the treatment for a particular type of disease or condition, a positive control (a compound or composition known to exhibit the desired therapeutic effect) and a negative control (a subject or a sample that does not receive the therapy or receives a placebo) are typically employed.

[00164] As used herein, the term“effective amount” refers to a quantity sufficient to achieve a desired therapeutic and/or prophylactic effect, e.g., an amount which results in the prevention of, or a decrease in a disease or condition described herein or one or more signs or symptoms associated with a disease or condition described herein. In the context of therapeutic or prophylactic applications, the amount of a composition administered to the subject will vary depending on the composition, the degree, type, and severity of the disease and on the characteristics of the individual, such as general health, age, sex, body weight and tolerance to drugs. The skilled artisan will be able to determine appropriate dosages depending on these and other factors. The compositions can also be administered in combination with one or more additional therapeutic compounds. In the methods described herein, the therapeutic compositions may be administered to a subject having one or more signs or symptoms of AML. As used herein, a“therapeutically effective amount” of a composition refers to composition levels in which the physiological effects of a disease or condition are ameliorated or eliminated. A therapeutically effective amount can be given in one or more administrations.

[00165] As used herein,“expression” includes one or more of the following: transcription of the gene into precursor mRNA; splicing and other processing of the precursor mRNA to produce mature mRNA; mRNA stability; translation of the mature mRNA into protein (including codon usage and tRNA availability); and glycosylation and/or other modifications of the translation product, if required for proper expression and function.

[00166] As used herein, the term“gene” means a segment of DNA that contains all the information for the regulated biosynthesis of an RNA product, including promoters, exons, introns, and other untranslated regions that control expression.

[00167] “Homology” or“identity” or“similarity” refers to sequence similarity between two peptides or between two nucleic acid molecules. Homology can be determined by comparing a position in each sequence which may be aligned for purposes of comparison. When a position in the compared sequence is occupied by the same nucleobase or amino acid, then the molecules are homologous at that position. A degree of homology between sequences is a function of the number of matching or homologous positions shared by the sequences. A polynucleotide or polynucleotide region (or a polypeptide or polypeptide region) has a certain percentage (for example, at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98% or 99%) of“sequence identity” to another sequence means that, when aligned, that percentage of bases (or amino acids) are the same in comparing the two sequences. This alignment and the percent homology or sequence identity can be determined using software programs known in the art. In some embodiments, default parameters are used for alignment. One alignment program is BLAST, using default parameters. In particular, programs are BLASTN and BLASTP, using the following default parameters: Genetic code=standard; filter=none; strand=both; cutoff=60; expect=10;

Matrix=BLOSUM62; Descriptions=50 sequences; sort by═HIGH SCORE; Databases=non- redundant, GenBank+EMBL+DDBJ+PDB+GenBank CDS

translations+SwissProtein+SPupdate+PIR. Details of these programs can be found at the National Center for Biotechnology Information. Biologically equivalent polynucleotides are those having the specified percent homology and encoding a polypeptide having the same or similar biological activity. Two sequences are deemed“unrelated” or“non-homologous” if they share less than 40% identity, or less than 25% identity, with each other. [00168] The term“hybridize” as used herein refers to a process where two substantially complementary nucleic acid strands (at least about 65% complementary over a stretch of at least 14 to 25 nucleotides, at least about 75%, or at least about 90%

complementary) anneal to each other under appropriately stringent conditions to form a duplex or heteroduplex through formation of hydrogen bonds between complementary base pairs. Nucleic acid hybridization techniques are well known in the art. See, e.g., Sambrook, et al., 1989, Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Press, Plainview, N.Y. Hybridization and the strength of hybridization (i.e., the strength of the association between the nucleic acids) is influenced by such factors as the degree of complementarity between the nucleic acids, stringency of the conditions involved, and the thermal melting point (T _m ) of the formed hybrid. Those skilled in the art understand how to estimate and adjust the stringency of hybridization conditions such that sequences having at least a desired level of complementarity will stably hybridize, while those having lower complementarity will not. For examples of hybridization conditions and parameters, see, e.g., Sambrook, et al., 1989, Molecular Cloning: A Laboratory Manual, Second Edition, Cold Spring Harbor Press, Plainview, N.Y.; Ausubel, F. M. et al.1994, Current Protocols in Molecular Biology, John Wiley & Sons, Secaucus, N.J. In some embodiments, specific hybridization occurs under stringent hybridization conditions. An oligonucleotide or polynucleotide (e.g., a probe or a primer) that is specific for a target nucleic acid will “hybridize” to the target nucleic acid under suitable conditions.

[00169] As used herein,“oligonucleotide” refers to a molecule that has a sequence of nucleic acid bases on a backbone comprised mainly of identical monomer units at defined intervals. The bases are arranged on the backbone in such a way that they can bind with a nucleic acid having a sequence of bases that are complementary to the bases of the

oligonucleotide. The most common oligonucleotides have a backbone of sugar phosphate units. A distinction may be made between oligodeoxyribonucleotides that do not have a hydroxyl group at the 2' position and oligoribonucleotides that have a hydroxyl group at the 2' position. Oligonucleotides may also include derivatives, in which the hydrogen of the hydroxyl group is replaced with organic groups, e.g., an allyl group. One or more bases of the oligonucleotide may also be modified to include a phosphorothioate bond (e.g., one of the two oxygen atoms in the phosphate backbone which is not involved in the internucleotide bridge, is replaced by a sulfur atom) to increase resistance to nuclease degradation. The exact size of the oligonucleotide will depend on many factors, which in turn depend on the ultimate function or use of the oligonucleotide. The oligonucleotide may be generated in any manner, including, for example, chemical synthesis, DNA replication, restriction endonuclease digestion of plasmids or phage DNA, reverse transcription, PCR, or a combination thereof. The oligonucleotide may be modified e.g., by addition of a methyl group, a biotin or digoxigenin moiety, a fluorescent tag or by using radioactive nucleotides.

[00170] As used herein, the term“pharmaceutically-acceptable carrier” is intended to include any and all solvents, dispersion media, coatings, antibacterial and antifungal compounds, isotonic and absorption delaying compounds, and the like, compatible with pharmaceutical administration. Pharmaceutically-acceptable carriers and their formulations are known to one skilled in the art and are described, for example, in Remington's

Pharmaceutical Sciences (20 ^th edition, ed. A. Gennaro, 2000, Lippincott, Williams & Wilkins, Philadelphia, Pa.).

[00171] As used herein, the term“polynucleotide” or“nucleic acid” means any RNA or DNA, which may be unmodified or modified RNA or DNA. Polynucleotides include, without limitation, single- and double-stranded DNA, DNA that is a mixture of single- and double-stranded regions, single- and double-stranded RNA, RNA that is mixture of single- and double-stranded regions, and hybrid molecules comprising DNA and RNA that may be single-stranded or, more typically, double-stranded or a mixture of single- and double- stranded regions. In addition, polynucleotide refers to triple-stranded regions comprising RNA or DNA or both RNA and DNA. The term polynucleotide also includes DNAs or RNAs containing one or more modified bases and DNAs or RNAs with backbones modified for stability or for other reasons.

[00172] As used herein,“prevention”,“prevent”, or“preventing” of a disorder or condition refers to one or more compounds that, in a statistical sample, reduces the occurrence of the disorder or condition in the treated sample relative to an untreated control sample, or delays the onset of one or more symptoms of the disorder or condition relative to the untreated control sample. As used herein, preventing AML, includes preventing or delaying the initiation of symptoms of AML. As used herein, prevention of AML also includes preventing a recurrence of one or more signs or symptoms of AML.

[00173] As used herein, the term“sample” refers to clinical samples obtained from a subject. Biological samples may include tissues, cells, protein or membrane extracts of cells, mucus, sputum, bone marrow, bronchial alveolar lavage (BAL), bronchial wash (BW), and biological fluids (e.g., ascites fluid or cerebrospinal fluid (CSF)) isolated from a subject, as well as tissues, cells and fluids (blood, plasma, saliva, urine, serum etc.) present within a subject.

[00174] As used herein, the term“separate” therapeutic use refers to an administration of at least two active ingredients at the same time or at substantially the same time by different routes.

[00175] As used herein, the term“sequential” therapeutic use refers to administration of at least two active ingredients at different times, the administration route being identical or different. More particularly, sequential use refers to the whole administration of one of the active ingredients before administration of the other or others commences. It is thus possible to administer one of the active ingredients over several minutes, hours, or days before administering the other active ingredient or ingredients. There is no simultaneous treatment in this case.

[00176] As used herein, the term“simultaneous” therapeutic use refers to the

administration of at least two active ingredients by the same route and at the same time or at substantially the same time.

[00177] The term“specific” as used herein in reference to an oligonucleotide means that the nucleotide sequence of the oligonucleotide has at least 12 bases of sequence identity with a portion of a target nucleic acid when the oligonucleotide and the target nucleic acid are aligned. An oligonucleotide that is specific for a target nucleic acid is one that, under the stringent hybridization or washing conditions, is capable of hybridizing to the target nucleic acid of interest and not substantially hybridizing to nucleic acids which are not of interest. Higher levels of sequence identity are desirable and include at least 75%, at least 80%, at least 85%, at least 90%, at least 95% or at least 98% sequence identity.

[00178] The term“stringent hybridization conditions” as used herein refers to hybridization conditions at least as stringent as the following: hybridization in 50% formamide, 5xSSC, 50 mM NaH ₂ PO ₄ , pH 6.8, 0.5% SDS, 0.1 mg/mL sonicated salmon sperm DNA, and 5x Denhart's solution at 42 ^o C. overnight; washing with 2x SSC, 0.1% SDS at 45 ^o C; and washing with 0.2x SSC, 0.1% SDS at 45 ^o C. In another example, stringent hybridization conditions should not allow for hybridization of two nucleic acids which differ over a stretch of 20 contiguous nucleotides by more than two bases. [00179] As used herein, the terms“subject,”“individual,” or“patient” are used interchangeably and refer to an individual organism, a vertebrate, a mammal, or a human. In certain embodiments, the individual, patient or subject is a human.

[00180] As used herein, the terms“target sequence” and“target nucleic acid sequence” refer to a specific nucleic acid sequence to be modulated (e.g., inhibited or downregulated).

[00181] “Treating”,“treat”, or“treatment” as used herein covers the treatment of a disease or disorder described herein, in a subject, such as a human, and includes: (i) inhibiting a disease or disorder, i.e., arresting its development; (ii) relieving a disease or disorder, i.e., causing regression of the disorder; (iii) slowing progression of the disorder; and/or (iv) inhibiting, relieving, or slowing progression of one or more symptoms of the disease or disorder. In some embodiments, treatment means that the symptoms associated with the disease are, e.g., alleviated, reduced, cured, or placed in a state of remission.

[00182] It is also to be appreciated that the various modes of treatment or prevention of medical diseases and conditions as described are intended to mean“substantial,” which includes total but also less than total treatment or prevention, and wherein some biologically or medically relevant result is achieved. The treatment may be a continuous prolonged treatment for a chronic disease or a single, or few time administrations for the treatment of an acute condition.

SYNCRIP-specific Inhibitory Nucleic Acids of the Present Technology

[00183] Figures 18-24 show the nucleic acid sequences of seven human SYNCRIP transcript variants, represented by SEQ ID NOs: 5-11.

[00184] In one aspect, the present disclosure provides SYNCRIP-specific inhibitory nucleic acids comprising a nucleic acid molecule which is complementary to a portion of a SYNCRIP nucleic acid sequence selected from the group consisting of SEQ ID NOs: 5-11.

[00185] The present disclosure also provides an antisense nucleic acid comprising a nucleic acid sequence that is complementary to and specifically hybridizes with a portion of any one of SEQ ID NOs: 5-11 (SYNCRIP mRNA), thereby reducing or inhibiting SYNCRIP expression. The antisense nucleic acid may be antisense RNA, or antisense DNA. Antisense nucleic acids based on the known SYNCRIP gene sequence can be readily designed and engineered using methods known in the art. In some embodiments, the antisense nucleic acid comprises the nucleic acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, or a complement thereof. [00186] Antisense nucleic acids are molecules which are complementary to a sense nucleic acid strand, e.g., complementary to the coding strand of a double-stranded DNA molecule (or cDNA) or complementary to an mRNA sequence. Accordingly, an antisense nucleic acid can form hydrogen bonds with a sense nucleic acid. The antisense nucleic acid can be

complementary to an entire SYNCRIP coding strand, or to a portion thereof, e.g., all or part of the protein coding region (or open reading frame). In some embodiments, the antisense nucleic acid is an oligonucleotide which is complementary to only a portion of the coding region of SYNCRIP mRNA. In certain embodiments, an antisense nucleic acid molecule can be complementary to a noncoding region of the SYNCRIP coding strand. In some

embodiments, the noncoding region refers to the 5′ and 3′ untranslated regions that flank the coding region and are not translated into amino acids. For example, the antisense

oligonucleotide can be complementary to the region surrounding the translation start site of SYNCRIP. An antisense oligonucleotide can be, for example, about 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50 nucleotides in length.

[00187] An antisense nucleic acid can be constructed using chemical synthesis and enzymatic ligation reactions using procedures known in the art. For example, an antisense nucleic acid (e.g., an antisense oligonucleotide) can be chemically synthesized using naturally occurring nucleotides or modified nucleotides designed to increase the biological stability of the molecules or to increase the physical stability of the duplex formed between the antisense and sense nucleic acids, e.g., phosphorothioate derivatives and acridine substituted nucleotides. Examples of modified nucleotides which can be used to generate the antisense nucleic acid include 5-fluorouracil, 5-bromouracil, 5-chlorouracil, 5-hodouracil,

hypoxanthine, xanthine, 4-acetylcytosine, 5-(carboxyhydroxylmethyl)uracil, 5- carboxymethylaminomethyl-2-thouridine, 5-carboxymethylaminometh-yluracil,

dihydrouracil, beta-D-galactosylqueosine, inosine, N6-isopentenyladenine, 1-methylguanine, 1-methylinosine, 2,2-dimethylguanine, 2-methyladenine, 2-methylguanine, 3-methylcytosine, 5-metnylcytosine, N6-adenine, 7-methylguanine, 5-methylaminomethyluracil, 5- methoxyaminomethyl-2-thiouracil, beta-D-mannosylqueosine, 5′- methoxycarboxymethyluracil, 5-methoxyuracil, 2-methylthio-N6-isopenten-yladenine, uracil- 5-oxyacetic acid (v), wybutosine, pseudouracil, queosine, 2-thiocytosine, 5-methyl-2- thiouracil, 2-thlouracil, 4-thiouracil, 5-methyluracil, uracil-5-oxyacetic acid methylester, uracil-5-cxyacetic acid (v), 5-methyl-2-thiouracil, 3-(3-amino-3-N-2-carboxypropyl) uracil, (acp3)w, and 2,6-diaminopurine. Alternatively, the antisense nucleic acid can be produced biologically using an expression vector into which a nucleic acid has been subcloned in an antisense orientation (i.e., RNA transcribed from the inserted nucleic acid will be of an antisense orientation to a target nucleic acid of interest).

[00188] The antisense nucleic acid molecules may be administered to a subject or generated in situ such that they hybridize with or bind to cellular mRNA and/or genomic DNA encoding the protein of interest to thereby inhibit expression of the protein, e.g., by inhibiting transcription and/or translation. The hybridization can occur via Watson-Crick base pairing to form a stable duplex, or in the case of an antisense nucleic acid molecule which binds to DNA duplexes, through specific interactions in the major groove of the double helix.

[00189] In some embodiments, the antisense nucleic acid molecules are modified such that they specifically bind to receptors or antigens expressed on a selected cell surface, e.g., by linking the antisense nucleic acid molecules to peptides or antibodies which bind to cell surface receptors or antigens. In some embodiments, the antisense nucleic acid molecule is an alpha-anomeric nucleic acid molecule. An alpha-anomeric nucleic acid molecule forms specific double-stranded hybrids with complementary RNA in which, contrary to the usual β- units, the strands run parallel to each other (Gaultier et al., Nucleic Acids. Res.15:6625- 6641(1987)). The antisense nucleic acid molecule can also comprise a 2′-O - methylribonucleotide (Inoue et al., Nucleic Acids Res.15:6131-6148 (1987)) or a chimeric RNA-DNA analogue (Inoue et al., FEBS Lett.215:327-330 (1987)).

[00190] The present disclosure also provides a short hairpin RNA (shRNA) or small interfering RNA (siRNA) comprising a nucleic acid sequence that is complementary to and specifically hybridizes with a portion of any one of SEQ ID NOs: 5-11 (SYNCRIP mRNA), thereby reducing or inhibiting SYNCRIP expression. In some embodiments, the shRNA or siRNA is about 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28 or 29 base pairs in length. Double- stranded RNA (dsRNA) can induce sequence-specific post-transcriptional gene silencing (e.g., RNA interference (RNAi)) in many organisms such as C. elegans, Drosophila, plants, mammals, oocytes and early embryos. RNAi is a process that interferes with or significantly reduces the number of protein copies made by an mRNA. For example, a double-stranded siRNA or shRNA molecule is engineered to complement and hydridize to a mRNA of a target gene. Following intracellular delivery, the siRNA or shRNA molecule associates with an RNA-induced silencing complex (RISC), which then binds and degrades a complementary target mRNA (such as SYNCRIP mRNA). In some embodiments, the shRNA or siRNA comprises the nucleic acid sequence of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 18, SEQ ID NO: 19, SEQ ID NO: 20, or SEQ ID NO: 21.

[00191] The present disclosure also provides a ribozyme comprising a nucleic acid sequence that is complementary to and specifically hybridizes with a portion of any one of SEQ ID NOs: 5-11 (SYNCRIP mRNA), thereby reducing or inhibiting SYNCRIP expression. Ribozymes are catalytic RNA molecules with ribonuclease activity which are capable of cleaving a complementary single-stranded nucleic acid, such as an mRNA. Thus, ribozymes (e.g., hammerhead ribozymes (described in Haselhoff and Gerlach, Nature 334:585-591 (1988))) can be used to catalytically cleave SYNCRIP transcripts, thereby inhibiting translation of SYNCRIP.

[00192] A ribozyme having specificity for a SYNCRIP-encoding nucleic acid can be designed based upon a SYNCRIP nucleic acid sequence disclosed herein. For example, a derivative of a Tetrahymena L-19 IVS RNA can be constructed in which the nucleotide sequence of the active site is complementary to the nucleotide sequence to be cleaved in a SYNCRIP-encoding mRNA. See, e.g., U.S. Pat. No.4,987,071 and U.S. Pat. No.5,116,742. Alternatively, SYNCRIP mRNA can be used to select a catalytic RNA having a specific ribonuclease activity from a pool of RNA molecules. See, e.g., Bartel and Szostak (1993) Science 261:1411-1418, incorporated herein by reference.

[00193] The present disclosure also provides a synthetic guide RNA (sgRNA) comprising a nucleic acid sequence that is complementary to and specifically hybridizes with a portion of any one of SEQ ID NOs: 5-11 (SYNCRIP mRNA). Guide RNAs for use in CRISPR-Cas systems are typically generated as a single guide RNA comprising a crRNA segment and a tracrRNA segment. The crRNA segment and a tracrRNA segment can also be generated as separate RNA molecules. The crRNA segment comprises the targeting sequence that binds to a portion of any one of SEQ ID NOs: 5-11, and a stem portion that hybridizes to a tracrRNA. The tracrRNA segment comprises a nucleotide sequence that is partially or completely complementary to the stem sequence of the crRNA and a nucleotide sequence that binds to the CRISPR enzyme. In some embodiments, the crRNA segment and the tracrRNA segment are provided as a single guide RNA. In some embodiments, the crRNA segment and the tracrRNA segment are provided as separate RNAs. The combination of the CRISPR enzyme with the crRNA and tracrRNA make up a functional CRISPR-Cas system. Exemplary CRISPR-Cas systems for targeting nucleic acids, are described, for example, in [00194] In some embodiments, a synthetic guide RNA is a single RNA represented as comprising the following elements:

5ʹ-X1-X2-Y-Z-3ʹ where X1 and X2 represent the crRNA segment, where X1 is the targeting sequence that binds to a portion of any one of SEQ ID NOs: 5-11, X2 is a stem sequence the hybridizes to a tracrRNA, Z represents a tracrRNA segment comprising a nucleotide sequence that is partially or completely complementary to X2, and Y represents a linker sequence. In some embodiments, the linker sequence comprises two or more nucleotides and links the crRNA and tracrRNA segments. In some embodiments, the linker sequence comprises 2, 3, 4, 5, 6, 7, 8, 9, 10 or more nucleotides. In some embodiments, the linker is the loop of the hairpin structure formed when the stem sequence hybridized with the tracrRNA. [00195] In some embodiments, a synthetic guide RNA is provided as two separate RNAs where one RNA represents a crRNA segment: 5ʹ-X1-X2-3ʹ where X1 is the targeting sequence that binds to a portion of any one of SEQ ID NOs: 5-11, X2 is a stem sequence the hybridizes to a tracrRNA, and one RNA represents a tracrRNA segment, Z, that is a separate RNA from the crRNA segment and comprises a nucleotide sequence that is partially or completely complementary to X2 of the crRNA.

[00196] Exemplary crRNA stem sequences and tracrRNA sequences are provided, for example, in WO/2015/089465, which is incorporated by reference herein. In general, a stem sequence includes any sequence that has sufficient complementarity with a complementary sequence in the tracrRNA to promote formation of a CRISPR complex at a target sequence, wherein the CRISPR complex comprises the stem sequence hybridized to the tracrRNA. In general, degree of complementarity is with reference to the optimal alignment of the stem and complementary sequence in the tracrRNA, along the length of the shorter of the two sequences. Optimal alignment may be determined by any suitable alignment algorithm, and may further account for secondary structures, such as self-complementarity within either the stem sequence or the complementary sequence in the tracrRNA. In some embodiments, the degree of complementarity between the stem sequence and the complementary sequence in the tracrRNA along the length of the shorter of the two when optimally aligned is about or more than about 25%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 97.5%, 99%, or higher. In some embodiments, the stem sequence is about or more than about 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 40, 50, or more nucleotides in length. In some embodiments, the stem sequence and complementary sequence in the tracrRNA are contained within a single RNA, such that hybridization between the two produces a transcript having a secondary structure, such as a hairpin. In some embodiments, the tracrRNA has additional complementary sequences that form hairpins. In some embodiments, the tracrRNA has at least two or more hairpins. In some embodiments, the tracrRNA has two, three, four or five hairpins. In some embodiments, the tracrRNA has at most five hairpins.

[00197] In a hairpin structure, the portion of the sequence 5ʹ of the final“N” and upstream of the loop corresponds to the crRNA stem sequence, and the portion of the sequence 3ʹ of the loop corresponds to the tracrRNA sequence. Further non-limiting examples of single polynucleotides comprising a guide sequence, a stem sequence, and a tracr sequence are as follows (listed 5ʹ to 3ʹ), where“N” represents a base of a guide sequence (e.g. a modified oligonucleotide provided herein), the first block of lower case letters represent stem sequence, and the second block of lower case letters represent the tracrRNA sequence, and the final poly-T sequence represents the transcription terminator: (a)

NNNNNNNNNNNNNNNNNNNNgtttttgtactctcaagatttaGAAAtaaatcttgca gaagctacaaagataa ggcttcatgccgaaatcaacaccctgtcattttatggcagggtgttttcgttatttaaTT TTTT (SEQ ID NO: 12); (b) NNNNNNNNNNNNNNNNNNNNgtttttgtactctcaGAAAtgcagaagctacaaagataag gcttcatgccg aaatcaacaccctgtcattttatggcagggtgttttcgttatttaaTTTTTT (SEQ ID NO: 13); (c)

NNNNNNNNNNNNNNNNNNNNgtttttgtactctcaGAAAtgcagaagctacaaagat aaggcttcatgccg aaatcaacaccctgtcattttatggcagggtgtTTTTTT (SEQ ID NO: 14); (d)

NNNNNNNNNNNNNNNNNNNNgttttagagctaGAAAtagcaagttaaaataaggcta gtccgttatcaactt gaaaaagtggcaccgagtcggtgcTTTTTT (SEQ ID NO: 15); (e)

NNNNNNNNNNNNNNNNNNNNgttttagagctaGAAATAGcaagttaaaataaggcta gtccgttatcaac ttgaaaaagtgTTTTTTT (SEQ ID NO: 16); and (f)

NNNNNNNNNNNNNNNNNNNNgttttagagctagAAATAGcaagttaaaataaggcta gtccgttatcaTT TTTTTT (SEQ ID NO: 17).

[00198] Selection of suitable oligonucleotides for use in as a targeting sequence in a CRISPR Cas system depends on several factors including the particular CRISPR enzyme to be used and the presence of corresponding proto-spacer adjacent motifs (PAMs) downstream of the target sequence in the target nucleic acid. The PAM sequences direct the cleavage of the target nucleic acid by the CRISPR enzyme. In some embodiments, a suitable PAM is 5'- NRG or 5'-NNGRR (where N is any Nucleotide) for SpCas9 or SaCas9 enzymes (or derived enzymes), respectively. Generally the PAM sequences should be present between about 1 to about 10 nucleotides of the target sequence to generate efficient cleavage of the target nucleic acid. Thus, when the guide RNA forms a complex with the CRISPR enzyme, the complex locates the target and PAM sequence, unwinds the DNA duplex, and the guide RNA anneals to the complementary sequence on the opposite strand. This enables the Cas9 nuclease to create a double-strand break. In some embodiments, the sgRNA comprises the nucleic acid sequence of SEQ ID NO: 1 or SEQ ID NO: 2.

[00199] A variety of CRISPR enzymes are available for use in conjunction with the disclosed guide RNAs of the present disclosure. In some embodiments, the CRISPR enzyme is a Type II CRISPR enzyme. In some embodiments, the CRISPR enzyme catalyzes DNA cleavage. In some embodiments, the CRISPR enzyme catalyzes RNA cleavage. In some embodiments, the CRISPR enzyme is any Cas9 protein, for instance any naturally-occurring bacterial Cas9 as well as any chimeras, mutants, homologs or orthologs. Non-limiting examples of Cas proteins include Cas1, Cas1B, Cas2, Cas3, Cas4, Cas5, Cas6, Cas7, Cas8, Cas9 (also known as Csn1 and Csx12), Cas10, Csy1, Csy2, Csy3, Cse1, Cse2, Csc1, Csc2, Csa5, Csn2, Csm2, Csm3, Csm4, Csm5, Csm6, Cmr1, Cmr3, Cmr4, Cmr5, Cmr6, Csb1, Csb2, Csb3, Csx17, Csx14, Csx10, Csx16, CsaX, Csx3, Csx1, Csx15, Csf1, Csf2, Csf3, Csf4, homologues thereof, or modified variants thereof. In some embodiments, the CRISPR enzyme cleaves both strands of the target nucleic acid at the Protospacer Adjacent Motif (PAM) site. In some embodiments, the CRISPR enzyme is a nickase, which cleaves only one strand of the target nucleic acid.

Therapeutic Methods

[00200] The following discussion is presented by way of example only, and is not intended to be limiting.

[00201] One aspect of the present technology includes methods of treating a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP. Additionally or alternatively, in some embodiments, the present technology includes methods of treating AML. In one aspect, the present disclosure provides a method for inhibiting leukemic cell proliferation in a subject in need thereof, comprising administering to the subject a therapeutically effective amount of at least one SYNCRIP-specific inhibitory nucleic acid, wherein the at least one SYNCRIP-specific inhibitory nucleic acid is selected from the group consisting of antisense oligonucleotide, sgRNA, shRNA, and siRNA, and wherein the subject suffers from a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP. The AML may be T-cell acute lymphoblastic leukemia or B- cell acute lymphoblastic leukemia.

[00202] In some embodiments, the subject is diagnosed as having, suspected as having, or at risk of having a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP. Additionally or alternatively, in some embodiments, the subject is diagnosed as having AML.

[00203] In therapeutic applications, compositions or medicaments comprising an

SYNCRIP-specific inhibitory nucleic acid disclosed herein are administered to a subject suspected of, or already suffering from such a disease or condition (such as, a subject diagnosed with a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP and/or a subject diagnosed with AML), in an amount sufficient to cure, or at least partially arrest, the symptoms of the disease, including its complications and intermediate pathological phenotypes in development of the disease.

[00204] Subjects suffering from a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP and/or a subject diagnosed with AML can be identified by any or a combination of diagnostic or prognostic assays known in the art. For example, typical symptoms of AML include, but are not limited to, enlarged lymph nodes, anemia, neutropenia, leukopenia, leukostasis, chloroma, granulocytic sarcoma, myeloid sarcoma, fatigue, weakness, dizziness, chills, headaches, shortness of breath, thrombocytopenia, excess bruising and bleeding, frequent or severe nosebleeds, bleeding gums, gum pain and swelling, headache, weakness in one side of the body, slurred speech, confusion, sleepiness, blurry vision, vision loss, deep venous thrombosis (DVT), pulmonary embolism, bone or joint pain, swelling in the abdomen, seizures, vomiting, facial numbness, defects in balance, weight loss, fever, night sweats, and loss of appetite.

[00205] In some embodiments, the subject may exhibit one or more point mutations in NRAS, DNMT3A, FLT3, KIT, IDH1, IDH2, CEBPA, and NPM1 and/or one or more chromosomal alterations (e.g., an inversion, translocation, or gene fusion) such as CBFB- MYH11, DEK-NUP214, MLL-MLLT3, PML-RARA, RBM15-MKL1, RPN1-EVI1 and RUNX1- RUNX1T1, and are detectable using techniques known in the art. See Naoe & Kiyoi, Int J Hematol.97(2):165-74 (2013); Shih et al., Nat Rev Cancer.12(9):599-612 (2012).

[00206] In some embodiments, subjects with a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP, and/or subjects suffering from AML that are treated with the SYNCRIP-specific inhibitory nucleic acid will show amelioration or elimination of one or more of the following symptoms: enlarged lymph nodes, anemia, neutropenia, leukopenia, leukostasis, chloroma, granulocytic sarcoma, myeloid sarcoma, fatigue, weakness, dizziness, chills, headaches, shortness of breath, thrombocytopenia, excess bruising and bleeding, frequent or severe nosebleeds, bleeding gums, gum pain and swelling, headache, weakness in one side of the body, slurred speech, confusion, sleepiness, blurry vision, vision loss, deep venous thrombosis (DVT), pulmonary embolism, bone or joint pain, swelling in the abdomen, seizures, vomiting, facial numbness, defects in balance, weight loss, fever, night sweats, and loss of appetite.

[00207] In certain embodiments, subjects with a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP, and/or subjects suffering from AML that are treated with the SYNCRIP-specific inhibitory nucleic acid will show reduced leukemic cell proliferation and/or increased survival compared to untreated AML subjects. In certain embodiments, subjects with a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP, and/or subjects suffering from AML that are treated with the SYNCRIP-specific inhibitory nucleic acid will show reduced SYNCRIP and/or HOXA9 expression levels compared to untreated AML subjects.

[00208] In one aspect, the present disclosure provides a method for monitoring the therapeutic efficacy of an SYNCRIP-specific inhibitory nucleic acid in a subject diagnosed with AML comprising: (a) detecting SYNCRIP protein levels in a test sample obtained from the subject after the subject has been administered the SYNCRIP-specific inhibitory nucleic acid; and (b) determining that the SYNCRIP-specific inhibitory nucleic acid is effective when the SYNCRIP protein levels in the test sample are reduced compared to that observed in a control sample obtained from the subject prior to administration of the SYNCRIP-specific inhibitory nucleic acid. The SYNCRIP-specific inhibitory nucleic acid may be an antisense oligonucleotide, a sgRNA, a shRNA, or a siRNA. The test sample may be tissues, cells or biological fluids (blood, plasma, saliva, urine, serum etc.) present within a subject.

Alternatively, HOXA9 expression levels may be used to determine efficacy of the SYNCRIP- specific inhibitory nucleic acid in the subject (see Example 9 described herein). Accordingly, in certain embodiments, the method further comprises detecting expression levels of HOXA9 in the subject, wherein a decrease in HOXA9 expression levels relative to those observed in the subject prior to treatment is indicative of the therapeutic efficacy of the SYNCRIP-specific inhibitory nucleic acid. Prophylactic Methods

[00209] In one aspect, the present technology provides a method for preventing or delaying the onset of a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP. Additionally or alternatively, in some aspects, the present technology provides a method for preventing or delaying the onset AML. The AML may be T-cell acute lymphoblastic leukemia or B-cell acute lymphoblastic leukemia.

[00210] Subjects at risk or susceptible to a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP, and/or subjects at risk or susceptible to AML include those that exhibit one or more point mutations in NRAS, DNMT3A, FLT3, KIT, IDH1, IDH2, CEBPA, and NPM1 and/or one or more chromosomal alterations (e.g., an inversion, translocation, or gene fusion) such as CBFB-MYH11, DEK-NUP214, MLL- MLLT3, PML-RARA, RBM15-MKL1, RPN1-EVI1 and RUNX1-RUNX1T1. Such subjects can be identified by, e.g., any or a combination of diagnostic or prognostic assays known in the art.

[00211] In prophylactic applications, pharmaceutical compositions or medicaments comprising an SYNCRIP-specific inhibitory nucleic acid disclosed herein are administered to a subject susceptible to, or otherwise at risk of a disease or condition characterized by elevated expression levels and/or increased activity of SYNCRIP, and/or a subject susceptible to, or otherwise at risk of AML, in an amount sufficient to eliminate or reduce the risk, or delay the onset of the disease, including biochemical, histologic and/or behavioral symptoms of the disease, its complications and intermediate pathological phenotypes presenting during development of the disease. Administration of a prophylactic SYNCRIP-specific inhibitory nucleic acid can occur prior to the manifestation of symptoms characteristic of the disease or disorder, such that the disease or disorder is prevented or, alternatively, delayed in its progression.

[00212] In some embodiments, treatment with the SYNCRIP-specific inhibitory nucleic acid will prevent or delay the onset of one or more of the following symptoms: leukemic cell proliferation, enlarged lymph nodes, anemia, neutropenia, leukopenia, leukostasis, chloroma, granulocytic sarcoma, myeloid sarcoma, fatigue, weakness, dizziness, chills, headaches, shortness of breath, thrombocytopenia, excess bruising and bleeding, frequent or severe nosebleeds, bleeding gums, gum pain and swelling, headache, weakness in one side of the body, slurred speech, confusion, sleepiness, blurry vision, vision loss, deep venous thrombosis (DVT), pulmonary embolism, bone or joint pain, swelling in the abdomen, seizures, vomiting, facial numbness, defects in balance, weight loss, fever, night sweats, and loss of appetite. In certain embodiments, (a) subjects with a disease or condition

characterized by elevated expression levels and/or increased activity of SYNCRIP, and/or (b) subjects with AML that are treated with the SYNCRIP-specific inhibitory nucleic acid will show SYNCRIP and/or HOXA9 expression levels that resemble those observed in healthy control subjects.

[00213] For therapeutic and/or prophylactic applications, a composition comprising an SYNCRIP-specific inhibitory nucleic acid disclosed herein, is administered to the subject. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered one, two, three, four, or five times per day. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered more than five times per day. Additionally or alternatively, in some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered every day, every other day, every third day, every fourth day, every fifth day, or every sixth day. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered weekly, bi- weekly, tri-weekly, or monthly. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered for a period of one, two, three, four, or five weeks. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered for six weeks or more. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered for twelve weeks or more. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered for a period of less than one year. In some embodiments, the SYNCRIP- specific inhibitory nucleic acid is administered for a period of more than one year. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered throughout the subject’s life.

[00214] In some embodiments of the methods of the present technology, the SYNCRIP- specific inhibitory nucleic acid is administered daily for 1 week or more. In some

embodiments of the methods of the present technology, the SYNCRIP-specific inhibitory nucleic acid is administered daily for 2 weeks or more. In some embodiments of the methods of the present technology, the SYNCRIP-specific inhibitory nucleic acid is administered daily for 3 weeks or more. In some embodiments of the methods of the present technology, the SYNCRIP-specific inhibitory nucleic acid is administered daily for 4 weeks or more. In some embodiments of the methods of the present technology, the SYNCRIP-specific inhibitory nucleic acid is administered daily for 6 weeks or more. In some embodiments of the methods of the present technology, the SYNCRIP-specific inhibitory nucleic acid is administered daily for 12 weeks or more. In some embodiments, the SYNCRIP-specific inhibitory nucleic acid is administered daily throughout the subject’s life.

Determination of the Biological Effect of SYNCRIP-specific Inhibitory Nucleic acids

[00215] In various embodiments, suitable in vitro or in vivo assays are performed to determine the effect of a specific SYNCRIP-specific inhibitory nucleic acid and whether its administration is indicated for treatment. In various embodiments, in vitro assays can be performed with representative animal models, to determine if a given SYNCRIP-specific inhibitory nucleic acid exerts the desired effect on reducing or eliminating signs and/or symptoms of AML. Compounds for use in therapy can be tested in suitable animal model systems including, but not limited to rats, mice, chicken, cows, monkeys, rabbits, and the like, prior to testing in human subjects. Similarly, for in vivo testing, any of the animal model system known in the art can be used prior to administration to human subjects. In some embodiments, in vitro or in vivo testing is directed to the biological function of one or more SYNCRIP-specific inhibitory nucleic acids.

[00216] Animal models of AML may be generated using techniques known in the art. Such models may be used to demonstrate the biological effect of SYNCRIP-specific inhibitory nucleic acids in the prevention and treatment of conditions arising from disruption of a particular gene, and for determining what comprises a therapeutically effective amount of the one or more SYNCRIP-specific inhibitory nucleic acids disclosed herein in a given context.

Modes of Administration and Effective Dosages

[00217] Any method known to those in the art for contacting a cell, organ or tissue with one or more SYNCRIP-specific inhibitory nucleic acids disclosed herein may be employed. Suitable methods include in vitro, ex vivo, or in vivo methods. In vivo methods typically include the administration of one or more SYNCRIP-specific inhibitory nucleic acids to a mammal, suitably a human. When used in vivo for therapy, the one or more SYNCRIP- specific inhibitory nucleic acids described herein are administered to the subject in effective amounts (i.e., amounts that have desired therapeutic effect). The dose and dosage regimen will depend upon the degree of the disease state of the subject, the characteristics of the particular SYNCRIP-specific inhibitory nucleic acid used, e.g., its therapeutic index, and the subject’s history. [00218] The effective amount may be determined during pre-clinical trials and clinical trials by methods familiar to physicians and clinicians. An effective amount of one or more SYNCRIP-specific inhibitory nucleic acids useful in the methods may be administered to a mammal in need thereof by any of a number of well-known methods for administering pharmaceutical compounds. The SYNCRIP-specific inhibitory nucleic acids may be administered systemically or locally.

[00219] The one or more SYNCRIP-specific inhibitory nucleic acids described herein can be incorporated into pharmaceutical compositions for administration, singly or in

combination, to a subject for the treatment or prevention of AML. Such compositions typically include the active agent and a pharmaceutically acceptable carrier. As used herein the term“pharmaceutically acceptable carrier” includes saline, solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents, and the like, compatible with pharmaceutical administration. Supplementary active compounds can also be incorporated into the compositions.

[00220] Pharmaceutical compositions are typically formulated to be compatible with its intended route of administration. Examples of routes of administration include parenteral (e.g., intravenous, intradermal, intraperitoneal or subcutaneous), oral, inhalation, transdermal (topical), intraocular, iontophoretic, and transmucosal administration. Solutions or suspensions used for parenteral, intradermal, or subcutaneous application can include the following components: a sterile diluent such as water for injection, saline solution, fixed oils, polyethylene glycols, glycerine, propylene glycol or other synthetic solvents; antibacterial agents such as benzyl alcohol or methyl parabens; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. pH can be adjusted with acids or bases, such as hydrochloric acid or sodium hydroxide. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic. For convenience of the patient or treating physician, the dosing formulation can be provided in a kit containing all necessary equipment (e.g., vials of drug, vials of diluent, syringes and needles) for a treatment course (e.g., 7 days of treatment).

[00221] Pharmaceutical compositions suitable for injectable use can include sterile aqueous solutions (where water soluble) or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersion. For intravenous administration, suitable carriers include physiological saline, bacteriostatic water, CREMOPHOR EL™ (BASF, Parsippany, N.J.) or phosphate buffered saline (PBS). In all cases, a composition for parenteral administration must be sterile and should be fluid to the extent that easy syringability exists. It should be stable under the conditions of manufacture and storage and must be preserved against the contaminating action of microorganisms such as bacteria and fungi.

[00222] The pharmaceutical compositions having one or more SYNCRIP-specific inhibitory nucleic acids disclosed herein can include a carrier, which can be a solvent or dispersion medium containing, for example, water, ethanol, polyol (e.g., glycerol, propylene glycol, and liquid polyethylene glycol, and the like), and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersion and by the use of surfactants. Prevention of the action of microorganisms can be achieved by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, ascorbic acid, thiomerasol, and the like. Glutathione and other antioxidants can be included to prevent oxidation. In many cases, it will be advantageous to include isotonic agents, for example, sugars, polyalcohols such as mannitol, sorbitol, or sodium chloride in the composition.

Prolonged absorption of the injectable compositions can be brought about by including in the composition an agent that delays absorption, for example, aluminum monostearate or gelatin.

[00223] Sterile injectable solutions can be prepared by incorporating the active compound in the required amount in an appropriate solvent with one or a combination of ingredients enumerated above, as required, followed by filtered sterilization. Generally, dispersions are prepared by incorporating the active compound into a sterile vehicle, which contains a basic dispersion medium and the required other ingredients from those enumerated above. In the case of sterile powders for the preparation of sterile injectable solutions, typical methods of preparation include vacuum drying and freeze drying, which can yield a powder of the active ingredient plus any additional desired ingredient from a previously sterile-filtered solution thereof.

[00224] Oral compositions generally include an inert diluent or an edible carrier. For the purpose of oral therapeutic administration, the active compound can be incorporated with excipients and used in the form of tablets, troches, or capsules, e.g., gelatin capsules. Oral compositions can also be prepared using a fluid carrier for use as a mouthwash.

Pharmaceutically compatible binding agents, and/or adjuvant materials can be included as part of the composition. The tablets, pills, capsules, troches and the like can contain any of the following ingredients, or compounds of a similar nature: a binder such as microcrystalline cellulose, gum tragacanth or gelatin; an excipient such as starch or lactose, a disintegrating agent such as alginic acid, Primogel, or corn starch; a lubricant such as magnesium stearate or Sterotes; a glidant such as colloidal silicon dioxide; a sweetening agent such as sucrose or saccharin; or a flavoring agent such as peppermint, methyl salicylate, or orange flavoring.

[00225] For administration by inhalation, the compounds can be delivered in the form of an aerosol spray from a pressurized container or dispenser, which contains a suitable propellant, e.g., a gas such as carbon dioxide, or a nebulizer. Such methods include those described in U.S. Pat. No.6,468,798.

[00226] Systemic administration of a therapeutic compound as described herein can also be by transmucosal or transdermal means. For transmucosal or transdermal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art, and include, for example, for transmucosal administration, detergents, bile salts, and fusidic acid derivatives. Transmucosal

administration can be accomplished through the use of nasal sprays. For transdermal administration, the active compounds are formulated into ointments, salves, gels, or creams as generally known in the art. In one embodiment, transdermal administration may be performed by iontophoresis.

[00227] A therapeutic agent can be formulated in a carrier system. The carrier can be a colloidal system. The colloidal system can be a liposome, a phospholipid bilayer vehicle. In one embodiment, the therapeutic agent is encapsulated in a liposome while maintaining the agent’s structural integrity. One skilled in the art would appreciate that there are a variety of methods to prepare liposomes. (See Lichtenberg, et al., Methods Biochem. Anal., 33:337-462 (1988); Anselem, et al., Liposome Technology, CRC Press (1993)). Liposomal formulations can delay clearance and increase cellular uptake (See Reddy, Ann. Pharmacother., 34(7- 8):915-923 (2000)). An active agent can also be loaded into a particle prepared from pharmaceutically acceptable ingredients including, but not limited to, soluble, insoluble, permeable, impermeable, biodegradable or gastroretentive polymers or liposomes. Such particles include, but are not limited to, nanoparticles, biodegradable nanoparticles, microparticles, biodegradable microparticles, nanospheres, biodegradable nanospheres, microspheres, biodegradable microspheres, capsules, emulsions, liposomes, micelles and viral vector systems. [00228] The carrier can also be a polymer, e.g., a biodegradable, biocompatible polymer matrix. In one embodiment, the therapeutic agent can be embedded in the polymer matrix, while maintaining the agent’s structural integrity. The polymer may be natural, such as polypeptides, proteins or polysaccharides, or synthetic, such as poly α-hydroxy acids.

Examples include carriers made of, e.g., collagen, fibronectin, elastin, cellulose acetate, cellulose nitrate, polysaccharide, fibrin, gelatin, and combinations thereof. In one embodiment, the polymer is poly-lactic acid (PLA) or copoly lactic/glycolic acid (PGLA). The polymeric matrices can be prepared and isolated in a variety of forms and sizes, including microspheres and nanospheres. Polymer formulations can lead to prolonged duration of therapeutic effect. (See Reddy, Ann. Pharmacother., 34(7-8):915-923 (2000)). A polymer formulation for human growth hormone (hGH) has been used in clinical trials. (See Kozarich and Rich, Chemical Biology, 2:548-552 (1998)).

[00229] Examples of polymer microsphere sustained release formulations are described in PCT publication WO 99/15154 (Tracy, et al.), U.S. Pat. Nos.5,674,534 and 5,716,644 (both to Zale, et al.), PCT publication WO 96/40073 (Zale, et al.), and PCT publication WO 00/38651 (Shah, et al.). U.S. Pat. Nos.5,674,534 and 5,716,644 and PCT publication WO 96/40073 describe a polymeric matrix containing particles of erythropoietin that are stabilized against aggregation with a salt.

[00230] In some embodiments, the therapeutic compounds are prepared with carriers that will protect the therapeutic compounds against rapid elimination from the body, such as a controlled release formulation, including implants and microencapsulated delivery systems. Biodegradable, biocompatible polymers can be used, such as ethylene vinyl acetate, polyanhydrides, polyglycolic acid, collagen, polyorthoesters, and polylactic acid. Such formulations can be prepared using known techniques. The materials can also be obtained commercially, e.g., from Alza Corporation and Nova Pharmaceuticals, Inc. Liposomal suspensions (including liposomes targeted to specific cells with monoclonal antibodies to cell-specific antigens) can also be used as pharmaceutically acceptable carriers. These can be prepared according to methods known to those skilled in the art, for example, as described in U.S. Pat. No.4,522,811.

[00231] The therapeutic compounds can also be formulated to enhance intracellular delivery. For example, liposomal delivery systems are known in the art, see, e.g., Chonn and Cullis,“Recent Advances in Liposome Drug Delivery Systems,” Current Opinion in

Biotechnology 6:698-708 (1995); Weiner,“Liposomes for Protein Delivery: Selecting Manufacture and Development Processes,” Immunomethods, 4(3):201-9 (1994); and

Gregoriadis,“Engineering Liposomes for Drug Delivery: Progress and Problems,” Trends Biotechnol., 13(12):527-37 (1995). Mizguchi, et al., Cancer Lett., 100:63-69 (1996), describes the use of fusogenic liposomes to deliver a protein to cells both in vivo and in vitro.

[00232] Dosage, toxicity and therapeutic efficacy of any therapeutic agent can be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., for determining the LD50 (the dose lethal to 50% of the population) and the ED50 (the dose therapeutically effective in 50% of the population). The dose ratio between toxic and therapeutic effects is the therapeutic index and it can be expressed as the ratio LD50/ED50. Compounds that exhibit high therapeutic indices are advantageous. While compounds that exhibit toxic side effects may be used, care should be taken to design a delivery system that targets such compounds to the site of affected tissue in order to minimize potential damage to uninfected cells and, thereby, reduce side effects.

[00233] The data obtained from the cell culture assays and animal studies can be used in formulating a range of dosage for use in humans. The dosage of such compounds may be within a range of circulating concentrations that include the ED50 with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed and the route of administration utilized. For any compound used in the methods, the therapeutically effective dose can be estimated initially from cell culture assays. A dose can be formulated in animal models to achieve a circulating plasma concentration range that includes the IC50 (i.e., the concentration of the test compound which achieves a half-maximal inhibition of symptoms) as determined in cell culture. Such information can be used to determine useful doses in humans accurately. Levels in plasma may be measured, for example, by high performance liquid chromatography.

[00234] Typically, an effective amount of the one or more SYNCRIP-specific inhibitory nucleic acids disclosed herein sufficient for achieving a therapeutic or prophylactic effect, range from about 0.000001 mg per kilogram body weight per day to about 10,000 mg per kilogram body weight per day. Suitably, the dosage ranges are from about 0.0001 mg per kilogram body weight per day to about 100 mg per kilogram body weight per day. For example dosages can be 1 mg/kg body weight or 10 mg/kg body weight every day, every two days or every three days or within the range of 1-10 mg/kg every week, every two weeks or every three weeks. In one embodiment, a single dosage of the therapeutic compound ranges from 0.001-10,000 micrograms per kg body weight. In one embodiment, one or more SYNCRIP-specific inhibitory nucleic acid concentrations in a carrier range from 0.2 to 2000 micrograms per delivered milliliter. An exemplary treatment regime entails administration once per day or once a week. In therapeutic applications, a relatively high dosage at relatively short intervals is sometimes required until progression of the disease is reduced or terminated, or until the subject shows partial or complete amelioration of symptoms of disease. Thereafter, the patient can be administered a prophylactic regime.

[00235] In some embodiments, a therapeutically effective amount of one or more

SYNCRIP-specific inhibitory nucleic acids may be defined as a concentration of inhibitor at the target tissue of 10 ^-32 to 10 ^-6 molar, e.g., approximately 10 ^-7 molar. This concentration may be delivered by systemic doses of 0.001 to 100 mg/kg or equivalent dose by body surface area. The schedule of doses would be optimized to maintain the therapeutic concentration at the target tissue, such as by single daily or weekly administration, but also including continuous administration (e.g., parenteral infusion or transdermal application).

[00236] The skilled artisan will appreciate that certain factors may influence the dosage and timing required to effectively treat a subject, including but not limited to, the severity of the disease or disorder, previous treatments, the general health and/or age of the subject, and other diseases present. Moreover, treatment of a subject with a therapeutically effective amount of the therapeutic compositions described herein can include a single treatment or a series of treatments.

[00237] The mammal treated in accordance with the present methods can be any mammal, including, for example, farm animals, such as sheep, pigs, cows, and horses; pet animals, such as dogs and cats; laboratory animals, such as rats, mice and rabbits. In some

embodiments, the mammal is a human.

Combination Therapy

[00238] In some embodiments, one or more of the SYNCRIP-specific inhibitory nucleic acids disclosed herein may be combined with one or more additional therapies for the prevention or treatment of AML. Additional therapeutic agents include, but are not limited to, chemotherapeutic agents, arsenic trioxide (Trisenox), all-trans retinoic acid (ATRA), and stem cell transplants.

[00239] In some embodiments, the one or more SYNCRIP-specific inhibitory nucleic acids disclosed herein may be separately, sequentially or simultaneously administered with at least one additional therapeutic agent selected from the group consisting of alkylating agents, topoisomerase inhibitors, endoplasmic reticulum stress inducing agents, antimetabolites, mitotic inhibitors, nitrogen mustards, nitrosoureas, alkylsulfonates, platinum agents, taxanes, vinca agents, anti-estrogen drugs, aromatase inhibitors, ovarian suppression agents,

VEGF/VEGFR inhibitors, EGF/EGFR inhibitors, PARP inhibitors, cytostatic alkaloids, cytotoxic antibiotics, antimetabolites, endocrine/hormonal agents, bisphosphonate therapy agents, phenphormin and targeted biological therapy agents (e.g., therapeutic peptides described in US 6306832, WO 2012007137, WO 2005000889, WO 2010096603 etc.). In some embodiments, the at least one additional therapeutic agent is a chemotherapeutic agent.

[00240] Specific chemotherapeutic agents include, but are not limited to,

cyclophosphamide, fluorouracil (or 5-fluorouracil or 5-FU), methotrexate, edatrexate (10- ethyl-10-deaza-aminopterin), thiotepa, carboplatin, cisplatin, taxanes, paclitaxel, protein- bound paclitaxel, docetaxel, vinorelbine, tamoxifen, raloxifene, toremifene, fulvestrant, gemcitabine, irinotecan, ixabepilone, temozolmide, topotecan, vincristine, vinblastine, eribulin, mutamycin, capecitabine, anastrozole, exemestane, letrozole, leuprolide, abarelix, buserlin, goserelin, megestrol acetate, risedronate, pamidronate, ibandronate, alendronate, denosumab, zoledronate, trastuzumab, tykerb, anthracyclines (e.g., daunorubicin and doxorubicin), cladribine, midostaurin, bevacizumab, oxaliplatin, melphalan, etoposide, mechlorethamine, bleomycin, microtubule poisons, annonaceous acetogenins, chlorambucil, ifosfamide, streptozocin, carmustine, lomustine, busulfan, dacarbazine, temozolomide, altretamine, 6-mercaptopurine (6-MP), cytarabine, floxuridine, fludarabine, hydroxyurea, pemetrexed, epirubicin, idarubicin, SN-38, ARC, NPC, campothecin, 9-nitrocamptothecin, 9- aminocamptothecin, rubifen, gimatecan, diflomotecan, BN80927, DX-8951f, MAG-CPT, amsacnne, etoposide phosphate, teniposide, azacitidine (Vidaza), decitabine, accatin III, 10- deacetyltaxol, 7-xylosyl-10-deacetyltaxol, cephalomannine, 10-deacetyl-7-epitaxol, 7- epitaxol, 10-deacetylbaccatin III, 10-deacetyl cephalomannine, streptozotocin, nimustine, ranimustine, bendamustine, uramustine, estramustine, mannosulfan, camptothecin, exatecan, lurtotecan, lamellarin D9-aminocamptothecin, amsacrine, ellipticines, aurintricarboxylic acid, HU-331, or combinations thereof.

[00241] Examples of antimetabolites include 5-fluorouracil (5-FU), 6-mercaptopurine (6- MP), capecitabine, cytarabine, floxuridine, fludarabine, gemcitabine, hydroxyurea, methotrexate, pemetrexed, and mixtures thereof. [00242] Examples of taxanes include accatin III, 10-deacetyltaxol, 7-xylosyl-10- deacetyltaxol, cephalomannine, 10-deacetyl-7-epitaxol, 7-epitaxol, 10-deacetylbaccatin III, 10-deacetyl cephalomannine, and mixtures thereof.

[00243] Examples of DNA alkylating agents include cyclophosphamide, chlorambucil, melphalan, bendamustine, uramustine, estramustine, carmustine, lomustine, nimustine, ranimustine, streptozotocin; busulfan, mannosulfan, and mixtures thereof.

[00244] Examples of topoisomerase I inhibitor include SN-38, ARC, NPC, camptothecin, topotecan, 9-nitrocamptothecin, exatecan, lurtotecan, lamellarin D9-aminocamptothecin, rubifen, gimatecan, diflomotecan, BN80927, DX-8951f, MAG-CPT, and mixtures thereof. Examples of topoisomerase II inhibitors include amsacrine, etoposide, etoposide phosphate, teniposide, daunorubicin, mitoxantrone, amsacrine, ellipticines, aurintricarboxylic acid, doxorubicin, and HU-331 and combinations thereof.

[00245] In certain embodiments, an additional therapeutic agent is administered to a subject in combination with the one or more SYNCRIP-specific inhibitory nucleic acids disclosed herein such that a synergistic therapeutic effect is produced. For example, administration of one or more SYNCRIP-specific inhibitory nucleic acids with one or more additional therapeutic agents for the prevention or treatment of AML will have greater than additive effects in the prevention or treatment of the disease. For example, lower doses of one or more of the therapeutic agents may be used in treating or preventing AML resulting in increased therapeutic efficacy and decreased side-effects. In some embodiments, the one or more SYNCRIP-specific inhibitory nucleic acids disclosed herein are administered in combination with any of the at least one additional therapeutic agents described above, such that a synergistic effect in the prevention or treatment of AML results.

[00246] In any case, the multiple therapeutic agents may be administered in any order or even simultaneously. If simultaneously, the multiple therapeutic agents may be provided in a single, unified form, or in multiple forms (by way of example only, either as a single pill or as two separate pills). One of the therapeutic agents may be given in multiple doses, or both may be given as multiple doses. If not simultaneous, the timing between the multiple doses may vary from more than zero weeks to less than four weeks. In addition, the combination methods, compositions and formulations are not to be limited to the use of only two agents. Kits

[00247] The present disclosure also provides kits for the prevention and/or treatment of AML comprising one or more SYNCRIP-specific inhibitory nucleic acids comprising a nucleic acid sequence selected from the group consisting of SEQ ID NOs: 1-2, 18-21 or any complement thereof. Optionally, the above described components of the kits of the present technology are packed in suitable containers and labeled for the prevention and/or treatment of AML.

[00248] The above-mentioned components may be stored in unit or multi-dose containers, for example, sealed ampoules, vials, bottles, syringes, and test tubes, as an aqueous, preferably sterile, solution or as a lyophilized, preferably sterile, formulation for

reconstitution. The kit may further comprise a second container which holds a diluent suitable for diluting the pharmaceutical composition towards a higher volume. Suitable diluents include, but are not limited to, the pharmaceutically acceptable excipient of the pharmaceutical composition and a saline solution. Furthermore, the kit may comprise instructions for diluting the pharmaceutical composition and/or instructions for administering the pharmaceutical composition, whether diluted or not. The containers may be formed from a variety of materials such as glass or plastic and may have a sterile access port (for example, the container may be an intravenous solution bag or a vial having a stopper which may be pierced by a hypodermic injection needle). The kit may further comprise more containers comprising a pharmaceutically acceptable buffer, such as phosphate-buffered saline, Ringer's solution and dextrose solution. It may further include other materials desirable from a commercial and user standpoint, including other buffers, diluents, filters, needles, syringes, culture medium for one or more of the suitable hosts. The kits may optionally include instructions customarily included in commercial packages of therapeutic or diagnostic products, that contain information about, for example, the indications, usage, dosage, manufacture, administration, contraindications and/or warnings concerning the use of such therapeutic or diagnostic products.

[00249] The kit can also comprise, e.g., a buffering agent, a preservative or a stabilizing agent. The kit can also contain a control sample or a series of control samples, which can be assayed and compared to the test sample. Each component of the kit can be enclosed within an individual container and all of the various containers can be within a single package, along with instructions for interpreting the results of the assays performed using the kit. The kits of the present technology may contain a written product on or in the kit container. The written product describes how to use the reagents contained in the kit. In certain embodiments, the use of the reagents can be according to the methods of the present technology.

EXAMPLES

[00250] The present technology is further illustrated by the following Examples, which should not be construed as limiting in any way. The following Examples demonstrate the preparation, characterization, and use of illustrative compositions of the present technology that inhibit SYNCRIP expression and/or activity.

Example 1: Experimental Materials and Methods

[00251] Pool description for gene prioritization used for in vivo shRNA screen. The number of genes used in the screen was determined based on previous studies that included approximately 100 genes (Cho S, et al., Mol Cell Biol.27:368–83 (2007)). Therefore, the genes in each pool were prioritized based on the following criteria. Pool 1 is made up of two sub-pools, 1a and 1b. Pool 1a was composed of differentially expressed genes prioritized based on Msi2 gene expression and other hematopoietic gene sets with a matrix score of 6 or more. Pool 1b was selected based on genes found in the leading edge taken from the GSEA with MSI2 overexpression in LSK cells overlapped with genes upregulated after shRNA depletion in CML/AML cell lines or leading edge genes in the rank list of Msi2 KO LSKs. Genes previously determined as canonical targets Numb, Numbl and CDKN1A, were added.

[00252] Pool 2 genes were chosen based on an intestinal CLIP-CHIP (UV-crosslinked mouse intestine) and immunoprecipitation for MSI1. MSI1 bound targets were ranked for the top 1000 genes, binding of the 3’UTR and their fold enrichment over the IgG control. These genes were ranked if they were MSI2-hematopoietic relevant genes. A combined score of 3 or more were included into the screen.

[00253] Pool 3 included MSI2 direct protein-protein interactors. A matrix score of 3 or more were chosen based on their ability to interact with MSI2 and was included in a MSI2 or hematopoietic relevant gene set.

[00254] Intestinal MSI-1 CLIP-CHIP used for pool 2 gene prioritization. UV-crosslinked mouse intestine was immunoprecipitated for MSI1. Similar CLIP protocol was performed as in Park et al., J Exp Med.211:71–87 (2014), with the exception that RNA was random primed and hybridized to Affymetric arrays 1.0ST array. Fold enrichment was ranked over IgG. [00255] Mass Spectrometry Methods and Analysis (used for Pool 3). K562 cells were grown with either MSCV-IRES-GFP or with FLAG-MSI2 and immunoprecipitated with FLAG antibody as previously described in Park et al., J Clin Invest.125:1286–98 (2015). 150 million cells per experiment were then stained, and the gel was cut into nine slices.

Control and MSI2 interacting proteins were considered to be represented if there were two or more peptides found and there was high confidence with a MASCOT score of either equal or greater than 20 or 77. Pairwise analysis was performed for two independent

immunoprecipitation experiments and mass spectrometry analyses. TOPGENE was performed with 234 MSI2 direct binding targets.

[00256] Lentiviral production, infection, and in vivo shRNA screen. Lentiviruses expressing shRNAs in the pLKO.1 vectors were obtained from RNAi consortium at the Broad Institute (Boston, MA). Virus production and preparation of pooled and titered lentiviruses for screening was performed as described in Miller et al., Cancer Cell. 24(1):45- 58 (2013). Pooled titered virus was thawed and kept on ice. L-GMPs (c-kit high cells top 50% were sorted). Infection, 12 well dishes were re-suspended into 600 µL virus + 600 µL of cells (2*10 ⁶ cells) per replicate (1.2mL/well). Cells were spinfected (2500 RPM, 90 minutes) and then cells were split for day 0 sequencing or injected into sub-lethally irradiated mice. Five pools representing a random set of ~100 shRNAs per pool with a total of titered 627 shRNA viruses were generated and used to transduce leukemia cells. Each transducing well was split: half was kept for sequencing and half was transplanted (1 million cells) into a sub-lethally irradiated recipient mice. There were five replicates per pool with five mice per pool with an experiment representing 25 total mice. After two weeks, cells were harvested from bone marrow and spleen and previously frozen cells for sequencing analysis. The sequences of the SYNCRIP shRNAs described herein are provided below:

[00257] Isolation, infection and selection of murine leukemia and normal cells. Tibia and femurs, pelvis, and arm bones from leukemia or C57Bl/6 wild-type mice (6-8 weeks old) were harvested, crushed, filtered, and subjected to red blood cell lysis (QIAGEN, Hilden, Germany). To isolate c-kit positive cells, bone marrow cells were incubated with CD117 microbeads (Miltenyi Biotec, Somerville MA), according to manufacturer’s instructions, and then subjected to positive selection using autoMACS Pro Separator. Cells were spinfected in RPMI with 10% FBS and cytokines: SCF (10 ng/ml), IL-3 (10 ng/ml), and IL-6 (10 ng/ml) and GM-CSF (10 ng/ml). 48 hours post-transduction, cells were treated with 2 μg/ml puromycin. Two days after puromycin selection, cells were harvested for further analysis.

[00258] Colony forming assay. 10,000 cells were plated on methocult GFM3434

(STEMCELL Technologies, Cambridge MA). Colonies were scored every five days for leukemia cells and every seven days for normal c-kit-enriched bone marrow cells.

[00259] In vivo transplantation of leukemia cells. MLL-AF9 tertiary mouse leukemia cells were transduced with lentiviruses expressing puromycin and shRNAs against Syncrip or a control shRNA. Transduced cells were selected by 2 μg/ml puromycin for 2 days. 50,000 selected cells were injected retro-orbitally into female C57Bl/6 (6-8 weeks old) recipient mice that had been sub-lethally irradiated with 475 cGy.

[00260] CRISPR/Cas9 approach to create SYNCRIP-CRISPR-knock out (CR-KO). The CRISPR gRNAs used for deleting exon 3 and 4 of the Syncrip gene were designed using the approach reported in Romanienko et al., PLoS One 11(2):e0148362 (2016). The sequence for the 5’-gRNA is GTACCTGTATTACCCAATGC (SEQ ID NO: 1) and sequence for the 3’-gRNA is CAATTTGGAATTGACCGCAC (SEQ ID NO: 2). Both sgRNAs were produced by in vitro transcription using the pU6T7 promoter in the hybrid plasmid described in Romanienko et al., PLoS One 11(2):e0148362 (2016). To initiate cleavage of the target locus in mice, gRNA (C67) and gRNA (C69) in conjunction with Cas9 mRNA were co- injected into the pronucleus of mouse zygotes at a concentration of 50 ng/µl each, using conventional techniques. Deleted samples were assayed using PCR primers:

CAGTGTTCAGGACTACTTGGACAC (SYNCRIPA) (SEQ ID NO: 3) and

GTCTATGCTTTCCATAGATGGTTGTAG (SYNCRIPD) (SEQ ID NO: 4), which are located outside of the gRNA cleavage sites (outside SYNCRIP exon 3-4) thereby revealing the size of the deletion based on the nucleotide length of the amplicon obtained (~ 900bp for wild-type vs. ~ 300 bp for deletion). [00261] Isolation of fetal liver cells, PCR genotyping and bone marrow transplantation. Fetal liver cells were isolated and single cell suspended based on standard protocols (Hemann M. Cold Spring Harb Protoc.2015(7):679-84 (2015). ~ 200,000 fetal liver cells after red blood cell lysis were used for DNA extracting using HotSHOT genomic DNA preparation methods. 2 µl supernatant containing DNA was used for PCR reactions with specific primers for detection of Syncrip exon 3-4. DNA was resolved in 1.5% agarose gel. 500,000 cells from confirmed wild-type and Syncrip-CR-KO fetal livers were retro-orbitally injected into lethally irradiated CD45.1 recipient mice. For secondary transplantation, 1 million bone marrow cells were retro-orbitally injected into lethally irradiated CD45.1 recipient mice.

[00262] Generation of MLL-AF9 primary leukemia and transplantation. Bone marrow cells from 6- to 10-week-old transplanted WT ^fl/fl or CR-SYNCRIP KO ^Δ/Δ mice were isolated and subsequently enriched for c-kit positive cells. c-kit enriched cells were stained with Lineage antibody cocktail (CD3, CD4, CD8, Gr1, B220, CD19, TER119 conjugated with PeCy5), Sca-Pac Blue, CD34-FITC, SLAM-APC, CD48-PE, and c-KIT-APC-Cy7. Lin- Sca ⁺ Kit ⁺ cells were sorted using a BD FACS Aria. Sorted cells were grown overnight in SFEM medium with 10 ng/ml IL-3, 10 ng/ml IL-6, 50 ng/ml SCF, 10 ng/ml thrombopoietin (TPO), and 20 ng/ml FLT3L. Cells were transduced twice with supernatant containing retroviruses expressing MLL-AF9 and GFP on retronectin-coated 96 well flat-bottom plates. The cells were expanded for one week in GFM3434 methylcellulose (STEMCELL

Technologies, Cambridge MA). MLL-AF9 transformed cells were sorted based on GFP positivity. 200,000 GFP ⁺ sorted cells and 250,000 helper cells were injected retro-orbitally into each lethally irradiated 6-8 week-old C57Bl/6 mouse.

[00263] Proliferation assay of human leukemia cells. Human leukemia cells were infected with viruses expressing scramble and hairpins against SYNCRIP by spinfection of cells in RPMI with 10% FBS together with viral supernatant. After 48 hours of infection, cells were treated with 3 μg/ml puromycin. Two days after puromycin selection, cells were plated at 250,000 cells/ml for proliferation assay. Cells were counted everyday using MUSE cell analyzer (EMD Millipore, Billerica MA) after plating. Cell growth was calculated based on normalization of cell number to cell number at plating. All cell lines were purchased from ATCC (Manassas, VA), and tested negative for mycoplasma contamination.

[00264] Intracellular staining and flow cytometry. For intracellular staining, cells were fixed with 1.5% paraformaldehyde at room temperature for 15 minutes and permeabilized with ice-cold methanol. Cells were washed 3 times with PBS and incubated with SYNCRIP antibody (MAB11004, EMD Millipore, Billerica MA) in 2% FBS PBS for 1 hour at room temperature. Cells were then washed twice with PBS and incubated with secondary antibody conjugated with Alexa Fluor 647 (Molecular Probes, Eugene OR) for 30 min at room temperature. Cells were washed with PBS and re-suspended prior to analysis using BD Fortessa instrument.

[00265] Cells were stained for Mac1-PB, Gr1-APC, F480-PE-Cy7, CD115-APC and c- Kit-APC-Cy7 and analyzed on a BD FACS LSR Fortessa instrument to assess differentiation status of wild-type and knockdown leukemia cells. For stem and progenitor cells analysis of fetal liver hematopoietic cells, 10 ⁶ cells were stained with stem/progenitor cells’ antibody panel including: lineage antibody cocktail (CD3, CD4, CD8, Gr1, B220, CD19, TER119 conjugated with PeCy5), Sca-Pac Blue, KIT-APC-Cy7, CD34-FITC, CD16/32-PE-CY7, CD48-PE and SLAM-CD150-APC. For analysis of engraftment in recipient mice, 10 ⁶ bone marrow cells were stained with stem/progenitor cells’ antibody panel and CD45.1-PE-Texas Red and CD45.2-A700.

[00266] To measure apoptosis, cells were washed with PBS and incubated with anti– ANNEXIN-V-PE (BD Biosciences, Franklin Lakes NJ) in the ANNEXIN-V binding buffer (10 mM HEPES, pH 7.4, 140 mM NaCl, 4 mM KCl, 0.75 mM MgCl ₂ , 1 mM CaCl ₂ ) in a reaction volume of 100 μl for 15 minutes. DAPI was added prior to analysis using a BD Fortessa instrument.

[00267] O-Propargyl-puromycin (OP-puro) flow analysis. Cells were plated at 100,000 cells/ml density and treated with 50 µM OP-Puro (NU-931-05, Jena Bioscience, Jena, Germany). Control cells were treated with cyclohexamide (CHX) at 150 µg/ml for 15 minutes. Cells were washed twice prior to collection and processed using Click-iT® Flow Cytometry Assay Kit (C10418, Invitrogen, Carlsbad CA) following the manufacturer’s instructions. Labelled cells were analyzed using BD Fortessa instrument.

[00268] Immunoprecipitation and immunoblot analysis. K562 cells were collected by spinning down at 1,500 rpm for five minutes at 4°C, washed twice with PBS, and then re- suspended thoroughly at 2x10 ⁷ per ml in 1× Ripa buffer (BP-115- Boston BioProducts, Ashland MA) with freshly added DTT (1mM) and proteinase inhibitor cocktail. The cells were incubated for 30 min on ice. Supernatant was then collected after the mix was spun at 14,000 rpm for 30 min at 4°C. For each immunoprecipitation assay, 250 µl of cell extract was mixed with 750 µl of 1x Ripa buffer 2 µg of anti-mouse/anti-SYNCRIP antibody or 2 µg anti-rabbit/anti-MSI2 and 50 µl agarose beads. For RNA independent assay, lysates were treated with RNase A (1µg/ml) for 30 min at 37°C prior to co-immunoprecipitation reactions. After rotating at 4°C overnight, beads were washed 5 times with 1×Ripa buffer and boiled with 1× Lamine protein running buffer.

[00269] For immunoblot analysis, cells were counted and washed twice with cold PBS prior to collection. ~ 250,000 cells were re-suspended and lysed in 40 µl 1× Lamine protein running buffer and boiled for 5 minutes. Whole cell lysates were run on 4%–15% gradient SDS-PAGE and transferred to nitrocellulose membrane. Membranes were blotted for SYNCRIP (MAB11004 or 05-1517; EMD Millipore, Billerica MA), IKZF2 (sc-9864; Santa Cruz Biotechnology, Dallas TX), HOXA9 (07-178; EMD Millipore, Billerica MA and ab140631; Abcam, Cambridge, UK), MYC (5605S; Cell Signaling Technology, Danvers MA), MSI2 (ab76148; Abcam, Cambridge, UK), and Actin (A3854; Sigma-Aldrich, St. Louis MO).

[00270] RNA immunoprecipitation. 30x10 ⁶ RN2 leukemia cells were used for RNA-IP using the Magna RIP RNA-binding protein immunoprecipitation kit (03-115; EMD

Millipore, Billerica MA). First, cells were washed with cold PBS and then lysed. Anti-rabbit antibody or anti-MSI2 antibody (EMD Millipore, Billerica MA); anti-mouse or anti- SYNCRIP (18E4; EMD Millipore, Billerica MA) incubated with magnetic beads was used to immunoprecipitate MSI2 and SYNCRIP. After washing, the immunoprecipitated complexes were treated with proteinase K. RNA extraction was performed by the phenol/chloroform method, and purified RNA was converted to cDNA using the Verso cDNA kit (Thermo Fisher Scientific, Waltham MA). Quantitative PCR was used for validating target mRNAs bound by MSI2 and SYNCRIP.

[00271] mRNA stability analysis. Control and SYNCRIP depleted cells were treated with 5 µg/ml of Actinomycin D and harvested at indicated time points. Total RNA was isolated using RNeasy RNA extraction kit. 200 ng of RNA was used for reverse transcription reaction and quantitative RT-PCR for Syncrip, Hoxa9, Ikzf2, Myc and β-actin was performed. β-actin served as a housekeeping gene control. Relative mRNA levels were normalized to the starting point of treatment.

[00272] Metabolic labeling and capture of newly synthesized protein. Newly synthesized proteins were labeled using the Click-iT Protein Labeling Kit (Invitrogen, Carlsbad CA). 48 hours after infection with corresponding shRNA-expressing plasmids, 1×10 ⁷ MOLM13 selected cells were cultured at 1x10 ⁶ cells/mL in fresh media for 14 hours. After one wash with PBS, cells were re-suspended in methionine-free RPMI 1640 medium (Gibco, Thermo Fisher Scientific, Waltham MA) supplemented with 10% dialyzed FBS (Gibco, Thermo Fisher Scientific, Waltham MA) for 30 min, at which point the methionine analog L- azidohomoalanine (AHA) was added (50 μM, 14 hours) to allow incorporation of AHA into nascent proteins. Cells were harvested and lysed in 50 mM Tris-HCl, pH 8.0, 1% SDS, with protease and phosphatase inhibitor mixes (complete and PhosSTOP, Roche, Basel,

Switzerland). 150 μg of total protein (up to 50 μL of lysate) were used in the crosslinking of AHA-labeled nascent proteins to an alkyne-derivatized biotin in the Click-iT Protein

Reaction Buffer (Invitrogen, Carlsbad CA) according to manufacturer’s instructions. The resulting precipitated total protein pellet was re-solubilized in 100 μL of 1% SDS PBS with protease inhibitors by pipetting, vortexing and incubating at 70°C for 10 minutes. The SDS was then quenched with 100 μL of 6% NP-40 in PBS with protease inhibitors. After centrifuging at 15,000 ×g for 5 minutes at room temperature to remove any insoluble particles, biotin-crosslinked nascent proteins were then captured overnight with streptavidin- coated Dynabeads M-280 (Invitrogen, Carlsbad CA) and then eluted from the beads by boiling the samples for 5 min in 2% SDS loading buffer for Western Blotting. Beads were thoroughly washed with PBS with 0.1% bovine serum albumin and 2% NP-40, first, and finally with PBS. The whole volume of AHA-labeled, biotin-crosslinked, streptavidin-pulled down protein was separated by SDS-PAGE together with lysate depleted of nascent protein after streptavidin incubation and input lysates.

[00273] RNA purification and quantitative Real time PCR (qRT-PCR). Total RNA was isolated using TRIzol and the Qiagen RNeasy Plus® mini kit (QIAGEN, Hilden, Germany). cDNA was generated from RNA using iScript™ cDNA Synthesis (Biorad Kit #1708891, Biorad Laboratories, Hercules CA) with random hexamers according to the manufacturer’s instructions. Real-time PCR reactions were performed using an ABI 7500 sequence detection system. Quantitative PCR for actin was performed to normalize for cDNA loading. Relative quantification of the genes was calculated using the method (2 ^-ΔΔCt ) as described by the manufacturer.

[00274] RNA sequencing. Total RNA was isolated from 9 individually transduced and processed MLL-AF9 murine leukemia cells (n=3 for each group including shRNA against luciferase, two shRNAs against SYNCRIP) using TRIzol and the Qiagen RNeasy Plus® mini kit (QIAGEN, Hilden, Germany). RNA was denatured and the first chain of cDNA was synthesized using oligo-dT primer containing illumina-compatible linker sequence. After removal of RNA, the second cDNA chain was synthesized with random decamer containing another illumina-compatible linker sequence. Illumina compatible annealing sequences and external barcodes were introduced during amplification of the libraries.

[00275] Differential expression and pathway analysis. Quality Control of raw reads was done using FastQC (v0.11.2) to make sure there were no major flaws in sequencing. The raw reads were then mapped to mm10 genome using STAR (v2.3.0e_r291) and default parameters. The mapped reads were counted using htseq-count (v0.6.0, parameters–t exon) and gene models from Ensembl (Mus_musculus.GRCm38.75.gtf). Differential expression was performed using DESeq2 (v1.2.10, default parameters).

[00276] Statistical analysis. Student’s t test was used for significance testing in the bar graphs, except where stated otherwise. A two-sample equal variance with normal distribution was used. P values less than 0.05 were considered significant. Graphs and error bars reflect mean + s.e.m, except where stated otherwise.

[00277] For animal study, survival probabilities were estimated using the Kaplan-Meier method and compared with the log-rank test. Ten mice per group were chosen to have an estimated 80% power in detecting a greater than 1.50 s.d. difference in means at a

significance level of α = 0.05 using a two-sided test. All animals were randomly assigned to the experimental groups. All statistical analyses were carried out using GraphPad Prism 4.0 and the R statistical environment.

[00278] Syncrip conditional knockout (cKO) mouse model. A Syncrip cKO mouse was generated by targeting the Syncrip locus in embryonic stem cells with a construct containing loxP sites flanking Syncrip exons 3 and 4 (Figure 25(A)). The neomycin resistance selection cassette was removed and a Syncrip ^flox/flox mouse colony was established. The Syncrip ^flox/flox mice were crossed with Mx-1 Cre mice and an inducible Syncrip loss of function strain (Syncrip ^flox/flox : Mx1-Cre) was generated.

Example 2: Identification of Novel Regulators of Leukemia Using Pooled In vivo shRNA Screening of the RNA-binding Protein Musashi2 (MSI2) Interactome

[00279] To identify which RBPs are required for the survival of myeloid leukemia, an in vivo pooled short hairpin (shRNAs) screen in MLL-AF9 driven leukemia cells enriched for LSCs was conducted. The mixed lineage leukemia (MLL) gene has been shown to be involved in chromosomal translocations in over 70% of childhood leukemia and 5-10% of leukemia in adult.

[00280] T(9;11) MLL-AF9 translocation is the most common translocation in acute myeloid leukemia (AML). Expression of the fusion protein MLL-AF9 in granulocyte- monocyte progenitor cells (GMPs) results in an established, robust, and short latency leukemia model, where LSCs can be enriched after serial transplantations (Miller PG, et al., Cancer Cell 24:45–58 (2013). MSI2 was used as a founding factor and mass spectrometry analysis was performed on FLAG-MSI2 immunoprecipitated complexes in a leukemia cell line (K562) (Figure 8(A)). A group of 234 proteins of multiple RBP classes were identified in association with MSI2 (Figure 1(A)). Functional GO term analysis linked these 234 proteins to RNA binding functions, including polyA binding and helicase activity (Figure 8(B)).

[00281] To obtain a comprehensive assessment of MSI2 functional networks, data generated from MSI2 associated genomic studies was used to prioritize genes in different candidate pools for functional screening. 51 genes with differential expression found in MSI2 depleted CML/AML cell lines, MSI2 overexpressing LSK cells, and MSI2 KO LSK cells were prioritized based on their associations with hematopoietic/leukemic gene sets, and Gene set enrichment analysis leading edge genes were included in Pool 1. Genes identified as MSI1 binding mRNA targets were ranked and evaluated for their relevance to MSI2 and hematopoietic system, and 19 genes were included in Pool 2. Similarly, 58 genes discovered from MSI2 protein-protein interactions and had relevance to hematopoietic/leukemic gene sets were selected for Pool 3.

[00282] A total of 128 genes were selected and 5-7 hairpins targeting each gene were obtained. Using a pooled library of titered shRNAs lentiviruses, LSC enriched cells (a tertiary transplant of c-kit enriched MLL-AF9-dsRed leukemia) were transduced sorted and subsequently transplanted into sub-lethally irradiated recipient mice (Figure 1(B)). The cells were allowed to engraft and then the relative representation of each shRNA in the leukemia cells was quantified from the bone marrow and spleen at day 0 and day 16 post

transplantation. See Figure 15 and Figure 16. A pool of shRNAs with greater than 20 fold depletion was recovered, which indicated a strong selection against their expression during leukemia progression (Figure 1(C) and Figures 8(C)-8(F)).

[00283] The 24 top hits were prioritized; each hit had at least five hairpins that resulted in 20-fold depletion in both the bone marrow and spleen (Figures 1(D)-1(E), Figure 15 and Figure 16). GO analysis of the top genes revealed a significant enrichment for RBPs and mRNA binding proteins. The majority of the hits (20/24) were in the MSI2-protein-protein interaction group (Pool 3), demonstrating that these complexes were important for disease progression (Figures 1(F)-1(G)). Among the top 24 scored genes, seven genes were selected (of which four encode RBPs) for in vitro validation including: SYNCRIP, Caprin, Dyrk2, Hnrnpr, Cct3, Mybbp1, and Hnrnpa3 (Figure 1(H) and Figure 8(G)). In all of the genes tested, knock down was confirmed and a reduction in colony formation was observed (Figure 1(I) and Figure 8(H)). Additionally, MLL-AF9 leukemia cells were generally more sensitive to shRNA depletion compared to normal cells (c-kit+ enriched from bone marrow), except for Dyrk2, which was equally depleted (Figure 1(I)). These data demonstrate that a dysregulated RBP network is differentially required for leukemia cell survival compared to normal cells.

[00284] Accordingly, the SYNCRIP-specific inhibitory nucleic acids disclosed herein are useful in methods for inhibiting leukemic cell proliferation and treating AML in a subject in need thereof.

Example 3: SYNCRIP is Required for Survival of Leukemia Cells

[00285] Of the in vitro validated genes from Example 2, SYNCRIP demonstrated the most differential effect (10-fold) in colony forming ability between leukemia cells and normal c- kit+ enriched cells. To further evaluate the effects of SYNCRIP depletion, it was first confirmed that shRNAs specific for SYNCRIP resulted in the reduction of SYNCRIP by immunoblot in MLL-AF9 transformed leukemia cells (Figure 2(A) and Figure 9(A)).

SYNCRIP depletion in leukemic cells resulted in rapid increase in myeloid differentiation based on increased Gr-1 and Mac-1, F480 and CD115 surface staining (Figures 2(B)-2(C) and Figures 9(B)-9(C)), and cellular morphology (Figure 2(D)) at day 4 post transduction. Significant change in c-kit level was only observed for SYNCRIP-depleted cells with one hairpin shRNA (shRNA#2) but not the other shRNA (shRNA#1) (Figure 9(D)). SYNCRIP- KD also resulted in apoptosis of leukemia cells at 5 days post transduction (Figure 2(E) and Figures 9(E)-9(F)), demonstrating that differentiating cells subsequently underwent apoptosis. SYNCRIP function was not restricted to MLL-AF9 driven leukemia; a similar reduction in colony formation of AML-ETO9a driven leukemia cells depleted for SYNCRIP was also observed (Figures 9(G)-9(H)). shRNA mediated depletion in MLL-AF9 leukemia cells was performed, which demonstrated a requirement for leukemic disease in vivo, (Figure 2(F)) since diseased mice with SYNCRIP-shRNA expressing leukemia cells selected for attenuated SYNCRIP-knockdown (Figures 9(I)- 9(J)).

[00286] To rule out the potential for off-target effects from shRNA mediated knockdown and to test an additional leukemia cell line, SYNCRIP-guide RNAs (gRNAs) were developed for CRISPR/Cas9 mediated deletion. RN2- myeloid leukemia cells (MLL-AF9, NRASG12D and expressing rtTA-RN2 cells) were transduced with vectors expressing the inducible (tetO) Cas9 and gRNAs specific for SYNCRIP or an empty vector (Cas9-EV) and sorted based on GFP positivity after induction by Doxycycline (Dox). A reduction in colony formation and proliferation with an increase in differentiation (Figures 2(G)-2(I) and Figures 9(K)-9(L)) in SYNCRIP depleted RN2 cells was observed. No significant change in percentage of c-kit high cells was observed upon SYNCRIP depletion (Figure 9(M)).

[00287] Multiple isoforms of SYNCRIP (UniProtKB - O60506 human SYNCRIP/HNRNP Q) are expressed in mammalian cells. To identify the SYNCRIP isoforms in leukemia, cDNAs encoding 3 different isoforms of SYNCRIP were overexpressed (hnRNP_Q1: 562 amino acids, Q3: 623 amino acids, and Q4: 527 amino acids) in RN2 cells. Immunoblot analysis demonstrated the existence of 2 SYNCRIP isoforms with the dominant isoform being Q1 (562 aa) and the alternative, larger isoform Q3 (623 aa) (Figure 9(N)). Despite the aggressiveness of the RN2 MLL-AF9 leukemia cells, SYNCRIP overexpression increased colony forming activity, demonstrating that SYNCRIP overexpression can potentiate leukemic cell growth (Figure 9(O)). Additionally, overexpression of SYNCRIP dominant isoform (562 aa) in RN2 cells drove a more rapid leukemia in vivo (Figure 2(J)).

[00288] Consistent with an on-target effect of CRISPR/Cas9 deletion for SYNCRIP, ectopic expression of non-target human SYNCRIP rescued the reduction in colony formation and reverse the increased differentiation from SYNCRIP depletion (Figures 2(K)-2(L) and Figures 9(P)-9(Q)). Therefore, the data shows that SYNCRIP is required for leukemic cell growth, cell survival, and maintenance of the undifferentiated state.

[00289] Accordingly, the SYNCRIP-specific inhibitory nucleic acids disclosed herein are useful in methods for inhibiting leukemic cell proliferation and treating AML in a subject in need thereof.

Example 4: CRIPSR/Cas9 Deletion of SYNCRIP Differentially Impairs Leukemogenesis but not Normal Hematopoiesis

[00290] To further assess SYNCRIP function in normal and malignant hematopoiesis in vivo, mice deficient for SYNCRIP were developed using CRISPR/Cas9 approach with co- injection of gRNAs and Cas9 mRNA into the pronucleus of mouse zygotes. Fetal liver cells were collected from developed embryos in pseudo moms at E14 and fetal liver genotypes were determined by PCR (Figures 3(A)-3(B) and Figure 10(A)). Confirmed wild type (WT) and CRIPSR-knockout samples (CR-KO) were analyzed, and an equivalent frequency of phenotypic HSCs in WTs versus CR-KOs was found (Figure 3(C) and Figure 10(B)) along with a modest increase in colony forming units granulocyte-macrophage (CFU-GM) in the CR-KOs (Figure 10(C)).

[00291] Analysis of SYNCRIP functions during normal hematopoiesis in vivo was performed by monitoring the engraftment efficiency of WT vs. CR-KO cells in transplanted recipient mice. Reduction of SYNCRIP protein expression in engrafted bone marrow cells from CR-KO compared to WT recipient was confirmed (Figures 3(D)-3(E)). No defect in engraftment of CR-KO cells in primary transplant mice was observed (Figure 3(F)).

[00292] To determine whether SYNCRIP is required for development of leukemia in vivo, LSKs cells from bone marrow of SYNCRIP WT and CR-KO primary transplanted mice were isolated and transduced with MLL-AF9-GFP expressing viruses. MLL-AF9-GFP

transformed cells were injected into recipient mice (Figure 3(G)). Additionally, a secondary bone marrow transplantation of SYNCRIP WT and CR-KO bone marrow cells into lethally irradiated mice was performed, which resulted in a mild reduction in engraftment (Figures 3(H)-3(I)). MLL-AF9-GFP transformed LSK cells derived from CR-KO recipients showed a delay in leukemogenesis in vivo when compared to WT cells (Figure 3(J)). It was determined that expression of SYNCRIP was maintained when the animals died of leukemia (Figure 3(K) and Figure 10(D)). This data shows that the CRISPR-driven KO fetal liver samples were mosaic for both WT and CR-KO SYNCRIP, resulting in the residual SYNCRIP-WT leukemia to grow out. Overall, this data show the requirement of SYNCRIP in the development of leukemia in a genetic mouse model.

[00293] Accordingly, the SYNCRIP-specific inhibitory nucleic acids disclosed herein are useful in methods for inhibiting leukemic cell proliferation and treating AML in a subject in need thereof.

Example 5: SYNCRIP is Highly Expressed and Essential for Human Leukemia Cells

[00294] To define SYNCRIP’s role in human leukemia, a previously published expression dataset was surveyed (Bagger FO et al., Nucleic Acids Res.41:D1034-9 (2013)). SYNCRIP expression was elevated in AML patients with diverse genetic alterations compared to normal hematopoietic stem and progenitor cells (Figure 4(A)). Elevated expression of SYNCRIP in other hematological malignancies including T-ALL and B-ALLs with various genetic abnormalities was also determined (Figure 11(A)). High levels of SYNCRIP expression were also observed across multiple human myeloid leukemia cell lines compared to normal human CD34 enriched cord blood cells (CB-CD34+ cells)( Figure 11(B)). SYNCRIP was highly expressed at the protein level in human myeloid leukemia cell lines (10/11) and primary patient samples (5 patients) compared to CB-CD34 cells (Figures 4(B)-4(C)).

[00295] To test the functional role of the increased SYNCRIP expression in leukemic cells, myeloid leukemia cells (MOLM13, NOMO-1, KASUMI-1 and NB4) were transduced with lentiviral shRNA vectors targeting SYNCRIP and knock down of SYNCRIP with 2 independent hairpins was obtained. Depletion of SYNCRIP resulted in reduced cell proliferation and increased apoptosis coupled with increased myeloid differentiation, depending on the particular marker, in the AML cell lines (Figures 4(D)-4(H) and Figures 11(C)-11(H)). This data shows that SYNCRIP plays a role in different types of human myeloid leukemia driven by various oncogenic drivers.

[00296] Accordingly, the SYNCRIP-specific inhibitory nucleic acids disclosed herein are useful in methods for inhibiting leukemic cell proliferation and treating AML in a subject in need thereof.

Example 6: SYNCRIP and MSI2 Co-regulate Leukemia Stem Cell Gene Expression Programs

[00297] To understand the molecular function of SYNCRIP in leukemia, RNA-sequencing was performed on MLL-AF9 leukemia cells transduced with shRNAs against SYNCRIP four days post-transduction. The transcriptional profile of SYNCRIP-shRNA transduced cells was significantly altered and the results obtained from two independent shRNA hairpins were highly correlated (Figure 12(A)). 282 genes were differentially expressed, where 57 were downregulated (SYNCRIP was ranked 9th most downregulated gene) and 225 were upregulated (Log ₂ Fold change>1.5, FDR<0.01, Figures 5(A), and Figure 17). The RNA- sequencing analysis was functionally annotated by performing Gene Set Enrichment Analysis (GSEA) on all curated gene sets in the Molecular Signatures Database (MSigDB, Broad Institute, Cambridge MA; 3,256 gene sets) combined with an additional set of relevant gene sets (92 gene sets from experimentally derived or published hematopoietic self-renewal and differentiation signatures) using the ranked list of differentially expressed genes in SYNCRIP-shRNA samples (Cntrl/SYNCRIP-shRNA). Genes upregulated after SYNCRIP depletion were enriched in 236 gene sets and downregulated genes were enriched in 172 gene sets. Set of genes downregulated in HSCs (CD133+ vs CD133-), LSC related gene signature associated with a good prognosis in AML and the myeloid development program were significantly enriched for upregulated genes in SYNCRIP depleted cells (Figures 5(B)-5(D)).

[00298] Additionally, it was found that MLL-AF9 direct targets were enriched for genes downregulated after SYNCRIP depletion (Figures 5(E)-5(F)). Consistent with the MLL program being reversed upon SYNCRIP knockdown, genes negatively regulated by

HOXA9/MEIS1 were enriched for genes suppressed by SYNCRIP (Figure 5(G)). Overall, these data demonstrate that SYNCRIP depletion results in a loss of the HSC/LSC program and the MLL-AF9 gene expression program. The studies show that SYNCRIP and MSI2 coregulate the LSC/MLL epigenetic program. Consistent with this observation, genes downregulated after SYNCRIP depletion were significantly enriched for MSI2’s direct mRNA binding targets (Top HITS-CLIP; Cross-linking immunoprecipitation followed by high throughput RNA-sequencing targets) (Figure 5(H)). Furthermore, genes upregulated in SYNCRIP depleted cells were enriched for genes that were also upregulated in Msi2 deleted LSCs (Figure 5(I)). Genes regulated by MSI2 including Hoxa9, c-Myc, Ikzf2, and Meis1 were found to be downregulated upon loss of SYNCRIP (Figure 12(B)).

[00299] A human expression dataset was examined (Figure 4(A)) and it was found that elevated SYNCRIP expression corresponded to an increase in HOXA9/MEIS1 target genes, IKZF2 and c-MYC, but without corresponding to altered MSI2 levels (Figures 12(C)-12(G)). Taken together, these data show that SYNCRIP and MSI2 coregulate a gene expression program that is essential for myeloid leukemia cells.

[00300] Accordingly, the SYNCRIP-specific inhibitory nucleic acids disclosed herein are useful in methods for inhibiting leukemic cell proliferation and treating AML in a subject in need thereof.

Example 7: SYNCRIP and MSI2 Interact Through Shared Common mRNA Targets

[00301] To investigate the interaction between SYNCRIP and MSI2, reciprocal immunoprecipitations were performed in MSI2 overexpressing leukemia cell line (K562) to confirm SYNCRIP as an identified protein-protein interacting partner of MSI2 from the mass-spectrometry data. The interaction was detected by reciprocal immunoprecipitation using antibodies against either MSI2 or SYNCRIP. It was found that the interaction is RNA- dependent, as treatment of the lysate with RNase diminished the interaction between the two proteins (Figure 6(A)).

[00302] A similar interaction was observed in MOLM13, a myeloid leukemia cell line carrying MLL-AF9 fusion protein (Figure 13(A)). This data shows that SYNCRIP and MSI2 bind to a common set of mRNA targets. To test if SYNCRIP and MSI2 share MSI2’s previously validated targets in MLL-AF9 driven leukemia, RNA-IP was performed. AS shown in Figure 6(B), SYNCRIP also binds Myc, Hoxa9, and Ikzf2 mRNA. Example 8: SYNCRIP Post-transcriptionally Regulates HOXA9 Expression

[00303] Targeted depletion of SYNCRIP with CRISPR/Cas9 or shRNA hairpins in multiple myeloid leukemia cells (RN2 cells, mouse dsRed MLL-AF9 cells and MOLM13 cells) significantly reduced HOXA9 (Figures 6(C)-6(D) and Figures 13(B)-13(C)). A decrease in c-MYC and IKZF2 was observed with CRISPR/Cas9 depletion of SYNCRIP in RN2 cells (Figure 6(C)), while reduction in c-MYC was observed at 4 days post transduction compared to 3 days post transduction in both dsRed MLL-AF9 cells and MOLM13 cells (Figure 6(D) and Figures 13(B)-13(C)). While these changes occurred at the protein level, variable reductions were also observed in mRNA levels of HoxA9, c-Myc, and Ikzf2 (Figures 13(D)-13(E), 13(H)-13(J)). MSI2 depletion reduced HOXA9 and c-MYC protein expression and downregulated HoxA9, c-Myc, and Ikzf2 mRNA levels at 4 days post transduction, similar to the phenotype observed in SYNCRIP knockdown cells (Figures 13(F)-13(G)).

[00304] To further understand the mechanism for SYNCRIP regulation of HOXA9 expression, the effects of SYNCRIP depletion on total RNA was examined. There was no change in SYNCRIP depleted cells compared to control cells (Figure 13(K)). Additionally, reduced HOXA9, c-MYC, and IKZF2 protein levels in SYCNRIP depleted cells were not due to an effect on mRNA stability, since mRNA levels of these genes were equivalent after the addition of actinomycin D to block transcription (Figures 13(L)-13(M)). Moreover, measurement of newly synthesized proteins based on AHA incorporation revealed a significant decrease in AHA labeled HOXA9 protein in SYNCRIP depleted cells. Despite its short half-life, c-MYC labeling at day 3 remained unchanged (Figure 6(E)), and global peptide synthesis was modestly increased by quantifying total OP-Puro incorporation (Figures 6(F)-6(G)). This data shows that SYNCRIP, in part, controls translation of specific targets including HOXA9.

[00305] Accordingly, the SYNCRIP-specific inhibitory nucleic acids disclosed herein are useful in methods for inhibiting leukemic cell proliferation and treating AML in a subject in need thereof.

Example 9: HOXA9 is a functional downstream target of SYNCRIP in leukemia cells

[00306] In support of SYNCRIP and MSI2 co-regulating the MLL-associated

transcriptional program, MSI2 overexpression rescued the reduced colony formation and reversed the reduction of HOXA9 after shRNA-SYNCRIP depletion (Figure 7(A) and Figures 14(A)-14(B)). Verifying the functional relationship between SYNCRIP and HOXA9, retroviral HOXA9 overexpression partially reversed the reduction in colony formation of dsRed MLL-AF9 cells after SYNCRIP depletion (Figures 7(B)-7(C) and Figures 14(C)- 14(D)). Similarly, overexpression of HOXA9 also rescued the cell growth in SYNCRIP-KD MOLM13 cells (Figures 7(D)-7(E)). In contrast, forced MYC expression failed to rescue the effects of SYNCRIP depletion (Figures 14(E)-14(H)). MYC protein levels were also reduced after SYNCRIP depletion but remained higher than the controls after shRNA depletion. This data shows that SYNCRIP maintains translation of the MLL and LSC program in part through its control of HOXA9 expression.

[00307] To directly demonstrate the relevance of SYNCRIP function in human leukemia, SYNCRIP expression was knocked down in leukemia cells derived from a primary AML patient by transducing cells with control shRNA or SYNCRIP-shRNAs. Engraftment of the cells in vivo was monitored after transplantation of sorted GFP positive transduced cells into recipient mice. Depletion of SYNCRIP protein expression resulted in a marked reduction in engraftment of human CD45 GFP positive leukemia cells at week 10 (for shRNA#1) and week 16 (for both shRNA#1 and #2) (Figure 7(F)). HOXA9 expression in the primary AML patient cells correlated with extent of SYNCRIP shRNA depletion (Figure 7(G)). This data shows that SYNCRIP regulates myeloid leukemia cell survival at least in part through regulating expression of HOXA9, a critical target in leukemia. Figure 7(H) shows a schematic depicting the dominant function of SYNCRIP when its expression is elevated in LSCs in comparison to normal HSCs. In LSCs, SYNCRIP and MSI2 binds and increases expression of the mRNA transcripts associated with the MLL self-renewal program, including Hoxa9 thus driving the LSC program instead of normal hematopoietic

development.

[00308] Accordingly, the SYNCRIP-specific inhibitory nucleic acids disclosed herein are useful in methods for inhibiting leukemic cell proliferation and treating AML in a subject in need thereof.

Example 10: Effects of SYNCRIP Depletion on Normal Hematopoietic Stem Cells Function and Leukemia Stem Cell Function Using SYNCRIP Conditional Knockout (cKO) Mouse Model

[00309] Using the Syncrip cKO mouse model described herein, the Cre transgene will be activated by injecting the mice with polyinositol-polycytosine (pIpC) three times. Deletion of Syncrip will be determined by PCR, quantitative real time PCR (qPCR) and western blot analysis within the hematopoietic stem and progenitor cells (HSPCs; LSK: Lineage ^lo c-kit ⁺ Sca ⁺ ). Cohorts of 10 animals of Syncrip deleted mice Syncrip ^Δ/Δ and control Syncrip ^flox/flox mice will be sacrificed and assessed for hematopoietic phenotypes. Complete analysis will include peripheral blood counts, histopathology, flow cytometry for terminally differentiated cells using Mac1, Gr1, B220, CD3, CD4 and CD8; multiparametric flow cytometry analysis to characterize the size and distribution of the stem and progenitor compartments; cell cycle analysis of stem and progenitor compartments using Hoechst and pyronin Y staining, and apoptosis analysis using Annexin V staining.

[00310] Stem cell function will be assayed using in vitro colony forming assays in methylcellulose, and in vivo long-term repopulating potential in non-competitive and competitive repopulation and serial transplantation assays (primary, secondary and tertiary). See Figure 25(B). It is anticipated that SYNCRIP depletion will not adversely impact hematopoietic homeostasis in normal hematopoietic stem cells.

[00311] As demonstrated herein, depletion of SYNCRIP with shRNAs and CRIPSR- sgRNAs resulted in apoptosis and growth inhibition of leukemia cells. To determine if SYNCRIP is required for LSC function and leukemia initiation and maintenance, retroviral transductions of MLL-AF9 oncogene to LSK cells isolated from 3 SYNCRIP deficient Syncrip ^Δ/Δ and 3 control mice will be performed. Transformed cells from each donor will be injected into 6 recipients mice. Survival of recipient mice will be monitored and a complete analysis will be performed at the time of sacrifice. Complete analysis will include peripheral blood counts, histopathology, flow cytometry for terminally differentiated cells using Mac1, Gr1, B220, CD3, CD4 and CD8; multiparametric flow cytometry analysis to characterize the size and distribution of the stem and progenitor compartments; cell cycle analysis of stem and progenitor compartments using Hoechst and pyronin Y staining, and apoptosis analysis using Annexin V staining.

[00312] To evaluate requirement of SYNCRIP for maintenance of leukemia in vivo, LSK isolated from Syncrip ^flox/flox : Mx1-Cre and control Syncrip ^flox/flox mice will be transformed with MLL-AF9 oncogene and the cells will be transplanted into recipient mice. Prior to onset of leukemia, pIpC injection will be initiated at week 12 and the animals will be evaluated as described above to determine whether loss of SYNCRIP will attenuate disease penetrance and/or latency or alter the disease phenotype. Frequency and number of LSCs will be determined by frequency of c-kit ^high cells and limiting-dilution transplantation of leukemia formed in recipient mice (Figure 25(C)). It is anticipated that SYNCRIP depletion will adversely impact LSC function and leukemia initiation and maintenance. [00313] Accordingly, the SYNCRIP-specific inhibitory nucleic acids disclosed herein are useful in methods for inhibiting leukemic cell proliferation and treating AML in a subject in need thereof.

EQUIVALENTS

[00314] The present technology is not to be limited in terms of the particular embodiments described in this application, which are intended as single illustrations of individual aspects of the present technology. Many modifications and variations of this present technology can be made without departing from its spirit and scope, as will be apparent to those skilled in the art. Functionally equivalent methods and apparatuses within the scope of the present technology, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the present technology. It is to be understood that this present technology is not limited to particular methods, reagents, compounds compositions or biological systems, which can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

[00315] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[00316] As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as“up to,”“at least,”“greater than,”“less than,” and the like, include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth. [00317] All patents, patent applications, provisional applications, and publications referred to or cited herein are incorporated by reference in their entirety, including all figures and tables, to the extent they are not inconsistent with the explicit teachings of this specification.