COMPOSITIONS AND METHODS FOR TREATING CANCER

This application claims priority to United States provisional patent application serial number 62/655,308, filed April 10, 2018, which is incorporated herein by reference in its entirety.

DEVELOPMENT

This invention was made with government support under grants CA186786 and CA214170 awarded by tire National Institutes of Health and under W81XWH-13-1-0284 and W81XWH-16-1-0314 awarded by the U.S. Army, Medical Research and Materiel Command. The government has certain rights in the invention.

FIELD

Provided herein are compositions and methods for treating cancer in particular, provided herein are compositions, methods, and uses of inhibitors of ARlncl for treating cancer.

BACKGROUND

27,000 Americans will die from prostate cancer (PCa) in 2017. PCa is the most common cancer in men and the number two killer overall. For patients with metastatic PCa that fail hormone therapy, the last line of defense are the taxane-derived ch emotherapeutic agents docetaxel (Taxotere) or cabazitaxel (Jevtana). Response to taxane therapy is not durable. Progression-free survival on docetaxel treatment approaches 0% by 3 years (see, e.g., Petryiak DP, et al., New Engl J Med. 2004:351(15): 1513-20).

There is a need for additional diagnostic and treatment options, particularly treatments customized to a patient’s tumor.

Provided herein are compositions and methods for treating cancer. In particular, provided herein are compositions, methods, and uses of inhibitors of ARlncl for treating cancer.

For example, in some embodiments, provided herein is a method of treating cancer, comprising: administering an agent that blocks the expression or activity of ARlncl to a subject diagnosed with cancer under conditions such that a sign or symptom of tire cancer is reduced. The present disclosure is not limited to particular agents. Examples include, but are not limited to, a nucleic acid (e.g., antisense, siRNA, miRNA, shRNA, etc.) that inhibits expression of ARlncl . The present disclosure is not limited to a particular cancer. In some embodiments, the cancer is prostate cancer. In some embodiments, the cancer expresses ARlncl . For example, in some embodiments, ARlncl is overexpressed in the cancer relative to the level of expression in non-cancerous cells. In some embodiments, the method further comprises the step of assaying a sample of the cancer for the level of expression of ARlnc l .

Further embodiments provide a method, comprising: a) assaying a sample from a subject diagnosed with cancer, wherein the sample comprises cancer tissue or cells, for the level of expression of ARlncl: and b) administering an agent that blocks the expression or activity of ARlncl when expression or overexpression of ARlncl is present in the sample.

Additional embodiments provide the use of an agent that inhibits expression of ARlncl to treat cancer in a subject.

Certain embodiments provide a composition compri sing an agent that inhibits expression of ARlncl for use in the treatment of cancer in a subject.

Also provided herein is a composition, comprising: a) an agent that inhibits expression of ARlncl; and b) a pharmaceutically acceptable earner.

Additional embodiments are described herein.

FIG. 1 shows identification of AR regulated genes in prostate cancer a, The androgen -regulated transcriptome of prostate cancer cells b, The landscape of transcriptomic alterations of prostate cancer progression c, A heatmap representation of ranked gene expression levels in prostate tissues.

FIG. 2 shows nomination and in situ characterization of ARLNC1 in prostate cancer a-b, Identification of androgen-regulated transcripts elevated in prostate cancer progression Y-axis depicts log2-fold change of gene expression upon DHT stimulation, and x-axis indicates log2-gene expression level difference between benign (n = 52 samples) and localized prostate cancer (n = 500 samples) (a), or expression level differences between benign (n = 52 samples) and metastatic prostate cancer (n = 100 samples) (b). c, Nomination of prostate cancer- and lineage- associated lncKNAs based on expression levels d, Relative expression (FPKM) of ARLNC1 across different cancer types in the TCGA cohort. Inset: relative expression (FPKM) of ARLNCi across benign (n = 52 samples), localized (n = 500 samples), and metastatic (n = 100 samples) prostate cancer e, In situ hybridization of ARLNC1 in human prostate cancer tissue microarray.

FIG. 3 shows that ARLNC1 is directly regulated by AR. a, AR ChIP-Seq in prostate cancer cell lines and tissues. Top, AR or control (IgG) ChIP-Seq results across the ARLNC1 locus in LNCaP and VCaP cells with vehicle (ethanol) treatment or DHT treatment. Bottom, AR ChIP-Seq in benign prostate and clinically-localized prostate cancer tissue b, ChlP- qPCR in MDA-PCa-2b cells showing AR or IgG enrichment (ChIP/input) over ARLNC 1 promoter region (Primer 1) or control region (Primer 2). Top: schematic of amplicon locations for ChIP-qPCR validation c, AR and AR target gene (ARLNC 1, TMPRSS2, SLC45A3, and KLK3) expression in MDA-PCa-2b cells transfected with control siKNA (si- NT) or siRNAs against AR (si-AR-pool, si-AR-1, si-AR-2).

FIG. 4 shows that ARLNC 1 loss attenuates AR signaling a, Gene expression profiling for ARLNC 1 knockdown in MDA-PCa-2b cells (n = 3 biologically independent cell cultures for each siRNA). b, Gene Set Enrichment Analysis (GSEA) showing significant enrichment of ARLNC I - regulated gene set with respect to the AR target gene sets (n = 3 independent gene expression profiles) c, Comparison of ARLNC 1 -regulated and AR target genes based on RNA-seq following knockdown of AR and ARLNC 1. d, siRNA knockdown of ARLNC1 in MDA-PCa-2b cells impairs AR signaling by AR reporter gene assay e, qRT- PCR analysis of ARLNC 1 and AR in MDA-PCa-2b cells transfected with siRNAs against ARLNC 1, AR, L/J 12. or non-specific control (NT). £ Immunoblot of AR, PSA, and GAPDH in MDA-PCa-2b cells transfected with siRN As against ARLNC 1, AR, EZH2, or non-specific control (NT).

FIG. 5 shows In situ co-localization between AR mRNA and ARLNC 1 in prostate cancer cells a, Schematic of predicted RNA-RNA interaction between ARLNC 1 and 3’UTR of AR. b, ARLNC 1 interacts with AR 3’UTR in an in vitro RNA-RNA interaction assay c-e, smFISH depiction of AR- ARLNC 1 colocalization in situ. Representative pseudocolored images of MDA-PCa-2b cell nuclei (c) stained for tire appropriate endogenous (endo) transcripts (green, red) and DAP! (nucleus, blue). Scale bar, 5 pm. Quantification of the percen tage of AR or ARLNC 1 molecules co-localizing with a panel of lncRNAs (d) or mRNAs (e) respectively. Orange circles represent regions of colocalization. Center line and whiskers depict the median and range respectively and box extends from 25th to 75th percentiles (n = 50 cells for each sample aggregated from 3 independent experiments) f-g, Representative pseudo-colored images of ARLNC 1 positive prostate cancer tissues (f) stained with DAPI (nucleus, blue) and AR (green), HMBS (red), or ARLNC 1 (red) transcripts (smFISH). Quantification of the percentage of AR molecules (g) colocalizing with HMBS or ARLNC1 is also depicted in box plot.

FIG. 6 shows identification of ARLNC1 fragment mediating RNA-RNA interaction with AR mRNA. a. In vitro RNA-RNA interaction assay identifies nucleotides 700-1300 on ARLNC1 as critical binding sites to AR 3’UTR-l-980. b, Deletion of nucleotides 700-1300 on ARLNC1 results in impaired binding to AR 3’UTR, as shown by in vitro RNA-RNA interaction assay c, Representative pseudo-colored images of U2-OS cells stained for DAPI (nucleus, blue), ARLNC1 (green) and A R transcripts (red) d, Quantification of the percent of AR molecules colocalizing with various ARLNC1 fragments e, Antisense oligos targeting sites 700-1300 on ARLNC1 transcript (Blocking ASO pool) inhibit ARLNC1 interaction with AR 3’UTR. f, smFISH shows that ASQs targeting 700-1300nt on ARLNCi transcript (ASO-Blocking) inhibit ARLNCI colocalization with AR in situ.

FIG. 7 shows that ARLNCI regulates cytoplasmic level of AR transcript a, ARLNCI regulates AR post-transeriptionaily by specifically affecting cytoplasmic AR mRNA. b, Fractional column plots depicting the nucleo-cytoplasmic distribution of AR mRNA after various treatment conditions in (a), as computed using smFISH.

FIG. 8 shows ARLNCI as a therapeutic target in AR-positive prostate cancer models a, siRNA knockdown of ARLNCI in vitro in AR-positive prostate cancer cell lines (MDA- PCa-2b and LNCaP) inhibits cell proliferation b, ARLNCI loss leads to increased apoptosis as shown by western blot analysis of PARP and cleaved PARI ⁵ in LNCaP cells following ARLNCI knockdown c, Tumor growth of LNCaP -AR cells expressing shRNA targeting ARLNCI or shRNA vector d. Gene expression profiling for siRNA -mediated or ASO- mediated ARLNCI knockdown in MDA-PCa-2b cells e, qRT-PCR analysis of ARLNCI, AR, and AR targets (KLK2, KLK3, FKBP5, and STEAP2) in MDA-PCa-2b cells transfected with ASOs against ARLNCI. f, Transfection of ASGs targeting ARLNCI in AR-positive MDA-PCa-2b cells inhibits cell proliferation g-h, Effect of ASO treatment on the growth of MDA-PCa-2b xenografts in male NOD-SCID mice, with control ASO (n = 15) or ARLNCI ASO (n = 13) treatment subcutaneously at 50 mg/kg, five times per week for three weeks. Tumors were measured by caliper bi-weekly (g) and tumor weights were measured at end point (h). i, Model depicting positive feedback loop between ARLNCI and ARthat is critical for prostate cancer growth.

FIG. 9 shows landscape of AR-regulated transcriptome in prostate cancer (a) A schematic illustration of the procedure used to discover AR-regulated genes (ARGs) in LNCaP and VCaP prostate cancer cell lines (b) Venn diagram indicating the overlap between AR-regulated genes in LNCaP and VCaP cells (c) qPCR analysis of ARLNC1 expression and AR signaling gene (KLK3, TMPRSS2) expression in LNCaP cells (top panel) and VCaP cells (botom panel), following DHT treatment of 6 hours or 24 hours (d) Bar plot depicting the distribution of gene biotypes (protein, lncRNA, and other) of all overlapped ARGs identified in both LNCaP and VCaP cells (e) Aggregate ChIP-Seq enrichment profile depicting AR ChIP-Seq signaling density on ARG promoters in LNCaP and VCaP ceils (f) Aggregate ChIP-Seq enrichment profile illustrating AR ChIP-Seq signaling density _' on ARG promoters in LNCaP cells following DHT stimulation, AR antagonist (enzalutamide) treatment, or BRD4 inhibitor (JQ1) treatment (g) Transcriptional response to DHT and enzalutamide treatment in VCaP ceils, plotting AR regulated protein-coding genes (top panel), or AR regulated IncRNAs (bottom panel) (h) Motif discovery analysis of the top 250 AR ChIP-Seq peaks on AR promoters identifies a binding motif similar to the canonical AR response element (i) Aggregated ChIPSeq enrichment profiles depicting ChIP-Seq signal density' on direct ARG promoters for H3K27ac, 1 13 K -l ine 1 . H3K4me3, H3K36me3, Pol P, and BRD4 in LNCaP cells (j) Pie chart showing prostate cell line or tissue distribution of direct ARGs with AR binding at transcription start sites (TSS) in ChIP-Seq. (k-1) Cumulative distribution plots of distances between transcription start sites (TSS) of genes to nearest AR peak (k) AR binding near ARGs in benign prostate, prostate cancer tissues (PCa), and prostate ceil lines. (1) Comparison of distances between AR binding sites for ARGs and genes not regulated by AR.

FIG. 10 shows that ARLNC1 is prioritized as a lineage-specific, cancer-associated lncRNA in prostate cancer (a) Tire top ten AR-regulated, localized prostate cancer-associated genes identified in Fig. 2a, after applying an expression filter of at least four fold change (log2FC = 2) upon DHT stimulation and at least 1 FPKM average expression m prostate cancer tissues (b) The top ten AR-regulated, metastatic prostate cancer-associated genes identified in Fig. 2b, after applying an expression filter of at least four fold change (3og2FC = 2) upon DHT stimulation and at least 1 FPKM average expression in prostate cancer tissues (c) Schematic illustration of the procedure used to nominate prostate lineage-specific, cancer- associated IncRNAs in prostate cancer (d) The top twelve prostate tissue-specific, prostate cancer-associated IncRNAs identified in Fig. 2c, after applying an expression filter of at least 10 FPKM m the prostate samples in the top 5% based on gene expression level (n = 7,256 samples) (e) Relative expression (FPKM) of ARLNC1 across a panel of normal tissues in GTEx normal tissue RNA-seq cohort (n = 9,435 samples) (f) Tissue and cancer-specific expression of ARLNC1 according to MiTranscriptome. (g) Oncomine concepts analysis of genes positively (top panel) or negatively (bottom panel) correlated with ARLNC1.

FIG. 1 1 shows characterization of ARLNC1 and its expression (a) Relative expression of ARLNC1 (FPKM) across 14 prostate cancer cell lines (b) qPCR analysis of ARLNC1 expression in nine prostate cancer ceil lines (c) Left: Representative image of ARLNC1 gene structure in MDA-PCa-2b and LNCaP cells, generated from RACE analysis (d) smFISH images depicting localization of ARLNC1 transcripts in a panel of prostate cancer cell lines (e) Scatter plot representing the average number of ARLNC1 transcripts per ceil in a panel of prostate cancer cell lines, including MDA-PCa-2b, LNCaP, VCaP, 22Rvl, PC3, RWPE, and DU145. (f) Representative gray-scale images of MDA-PCa-2b cells stained for DAPI (nucleus, blue) and ARLNC 1 , AR or GAPDH transcripts (smFISH, gray) (g) Percentage of nuclear/cytoplasmic RNA levels of ARLNC 1, ACTB, and U l, measured by qRT-PCR after subcellular fractionation of MDA-PCa-2b and LNCaP cells.

FIG. 12 shows that ARLNC 1 expression is regulated by AR and FO.XA1. (a) ChlP- seq peaks ofH3K4me l, MED1, BRD4, F0X.41 , and NKX3-l from LNCaP cells at the ARLNC 1 promoter region (b) Top panel: qPCR analysis of ARLNC 1 expression in LNCaP ceils, following treatment with siRNAs targeting AR FOXA1, NKX3-1, BRD4, EZH2, LSD1, IRF1, and POU 1F1. (c) ChIP-PCR analysis in MDA-PCa-2b cells showing relative enrichment (ChIP/input) of AR, FOXA1, NKX3-1 or IgG over ARLNC 1 promoter region or control region (d) Relative expression (TPM) of AR (Left) and FOXA1 (Right) across a panel of normal tissues in GTEx normal tissue RNA-seq cohost (n = 8,745 samples)

FIG. 13 shows a positive feedback loop between ARLNC 1 and AR signaling (a) Reproducibility of expression profiling following 10 nM DHT treatment in MDA-PCa-2b ceils (b) Overlap between genes differentially expressed upon AR knockdown and ARLNC 1 knockdown in MDA-PCa-2B cells (c) siRNA knockdown of ARLNC 1 in LNCaP cells impaired AR signaling by AR reposter gene assay (d) qRT-PCR analysis of KLK2, KLK3, and STEAP2, in MDA-PCa-2b cells transfected with siRNAs against ARLNC 1, AR, EZH2, or non-specific control (e) qPCR analysis of ARLNC 1 and AR signaling genes in LNCaP cells (Left panel) and MDA-PCa-2b cells (Right panel) transfected with ARLNC 1 expressing vector or control vector.

FIG. 14 shows post-transcriptional regulation of AR by ARLNC 1. (a) In siiico prediction of ARLNC 1 RNA-binding partners, with y-axis representing log2-absolute RNA binding energy between ARLNC I and various RNA species, while x-axis depicting log2- average expression level of these RNAs in prostate cancer (b) Stoichiometry of ARLNC1:AR colocalization (c) Representative pseudocolored images of U2-OS cells ectopically expressing ARLNC1 alone (green, left and right panels), or both ARLNC1 and AR (red, middle panel), and stained for the appropriate transcripts and DAPI (blue) (d-e) Representative pseudo-colored images of MDA-PCa- 2h cells or U2-OS cells stained for DAPI (nucleus, blue) and ARLNC1 (green) and AR transcripts (red), following treatment of blocking ASOs targeting the ARLNCLAR 3’UTR interaction. Quantification of

colocalization in U2-OS ceils are depicted in (e) as a box plot, whereas quantifications of colocalization MDA-PCa~2b cells are Fig. 6f. (f) qPCR analysis of ARLNC1, AR transcript and AR signaling gene (KLK2, KLK3, NKX3-1, TMPRSS2, FKBP5) expression in LNCaP cells transfected with control ASO or blocking oligos targeting the interaction sites between ARLNC1 and AR 3’UTR (g) Half-life of GAPDH, AR, ARLNC1, and MYC RNA transcripts in LNCaP cells (h-i) Quantification of ARLNC1 levels, as measured by smFISH, after treatment of MDA-PCa-2b cells with siRNA against AR (siAR), siRNA against ARLNC1 (siARLNCl-3), ASO against ARLNC1 (ASO-ARLNCl-1) or blocking ASO against AR-ARLNC1 colocalizing segment (A SO-B locking). Data were normalized to siNT (h) or ASO-Control (i). (j) Nucleo-cytoplasmic distribution of ARLNC1 after appropriate treatment of MDA-PCa-2b ceils with siRNA against AR (siAR), siRNA against ARLNC1 (siARLNCl-3), ASO against ARLNC1 (ASO-ARLNC 1-1) or blocking ASO against AR- ARLNC1 colocalizing segment (ASO-Blocking). (k-l) Quantification of AR levels, as measured by smFISH, after treatment of MDA-PCa-2b cells with siRNA against AR (si-AR), siRNA against ARLNC1 (si-ARLNCl-3), ASO against ARLNC1 (ASO-ARLNC 1-1) or blocking ASO against AR-ARLNC1 colocalizing segment (ASO-Blocking). Data were normalized to siNT (k) or ASO-Control (1). Mean ± s.e.m. are shown, n = 3 independent experiments and 60 cells analyzed for each sample (m-n) BrU-seq alignment track (m) and BrUChase-seq alignment track (n) at ARgene locus.

FIG. 15 shows evaluation of the phenotypic effect of ARLNC1 in vitro (a)

Knockdown efficacy of three independent siRNAs targeting ARLNC1 in MDA-PCa-2b cells (b) ARLNC1 siRNA transfection has no effect on cell proliferation in ARnegative prostate cancer cells, PCS. (c) Increased apoptosis observed in MDA-PCa~2b and LNCaP cells 48 hours after transfected with ARLNC1 siRNAs. (d) Positions of ARLNC1 antisense oligo (ASO)-targeting sites (1 to 6) is indicated on the schematic representation of the ARLNC1 transcript (e) MDA~PCa-2b cells were transfected with six independent ASOs targeting ARLNC1. (f) Correlation analysis of si RNA -mediated knockdown and A SO-mediated knockdown of ARLNC1 among replicated microarray experiments in MDA-PCa-2b ceils (n = 2 biological replicates per ASO treatment group and n = 3 biological replicates per siRNA treatment group) (g) Free-uptake efficacy of ARLNC1 ASOs was examined in MDA-PCa- 2B cells 72 hours post ASO addition to the culture medium (10 mM). (h) Free-uptake treatment of ASOs targeting ARLNC1 resulted in retarded growth of MDA-PCa-2b cells in vitro (i-j) ARLNC1 ASOs inhibit MDA-PCa-2b cell proliferation in 3D-sphere models.

FIG. 16 shows that knockdown of ARLNC 1 by ASOs inhibits tumor growth in vivo (a) Representative image of in situ hybridization for ARLNC 1 in MDA-PCa-2b cell line- derived xenograft (b) qRT-PCR analysis of ARLNC 1, NKX3-1 and AR transcripts in MDA- PCa-2b xenografts treated with control ASO (n = 15) or ASO targeting ARLNC 1 (n = 13).

(c) Left: Immunoblots of AR and GAPDH in MDA-PCa-2b xenografts treated with control ASO (n = 15) or ASO targeting ARLNC 1 (n = 13). Right: Relative intensity of the bands was quantified using Image! (d) Left: Immunohistochemistry staining for Ki67 in MDA-PCa-2b xenograft treated with control ASO or ASO against ARLN C 1. Right: Summary of Ki67 tumor staining for control (n = 15) or ARLNC 1 A SO-treated tumors (n = 13) show's significant difference in Ki67 staining intensity (e) Percent change in mice body weight over the time of ASO treatment in MDA-PCa-2b xenografts treated with control ASO (n = 15) or ASO targeting ARLNC 1 (n - 13). (i) ARLN Cl expression levels are not associated with Gleason score (g) Curated pathway signature analysis between ARLNC 1 high (top-quartile) and ARLNC 1 low (bottom-quartile) mCRPC samples (n = 100). (h) Signatures associated with prostate cancer and luminal differentiation were selected from the MSigDB and contrasted between ARLNC 1 high (top-quartile) and ARLNC 1 low (bottom-quartile) mCRPC samples (n = 100). (i) Cancer hallmark signature analysis between ARLNC 1 high expression (top-quartile) and ARLNC 1 low' expression (bottorn-quartile) mCRPC samples (n = 100 samples) (j) Tumor content estimated from whole-exome sequencing is compared between ARLNC 1 high (top-quartile) and ARLNC 1 low (bottom-quartile) expression in mCRPC samples (n = 100)

To facilitate an understanding of the present disclosure, a number of terms and phrases are defined below:

As used herein, the term“subject” refers to any animal (e.g., a mammal), including, but not limited to, humans, non-human primates, rodents, and the like, which is to be the recipient of a particular treatment. Typically, the terms“subject” and“patient” are used interchangeably herein in reference to a human subject. As used herein, the term“subject suspected of having cancer” refers to a subject that presents one or more symptoms indicative of cancer. A subject suspected of having cancer may also have one or more risk factors. A subject suspected of having cancer has generally not been tested for cancer. However, a“subject suspected of having cancer” encompasses an individual who has received a preliminary diagnosis but for whom a confirmatory test has not been done or for whom the level or severity of cancer is not known.

As used herein, the term“subject diagnosed with cancer” refers to a subject who has been tested and found to have cancer. As used herein, the term“initial diagnosis” refers to a test result of initial disease that reveals the presence or absence of disease.

As used herein, the term“non-human animals” refers to ail non-human animals including, but not limited to, vertebrates such as rodents, non-human primates, ovines, bovines, ruminants, lagomorphs, porcines, caprines, equines, canines, felines, aves, etc.

As used herein, the term“cell culture” refers to any in vitro culture of cells. Included within this tenn are continuous cell lines (e.g., w ith an immortal phenotype), primary cell cultures, transformed cell lines, finite cell lines (e.g., non-transformed cells), and any other ceil population maintained in vitro.

As used herein, the term“eukaryote” refers to organisms distinguishable from “prokaryotes.” It is intended that the term encompass all organisms with cells that exhibit the usual characteristics of eukaryotes, such as the presence of a true nucleus bounded by a nuclear membrane, within which lie the chromosomes, the presence of membrane-bound organelles, and other characteristics commonly observed in eukaryotic organisms. Thus, the tenn includes, but is not limited to such organisms as fungi, protozoa, and animals (e.g., humans).

As used herein, the term“in vitro” refers to an artificial environment and to processes or reactions that occur within an artificial environment. In vitro environments can consist of, but are not limited to, test tubes and cell culture. The tenn“in vivo” refers to the natural environment (e.g., an animal or a cell) and to processes or reaction that occur within a natural environment.

The temis“test compound” and“candidate compound” refer to any chemical entity, pharmaceutical, drug, and the like that is a candidate for use to treat or prevent a disease, illness, sickness, or disorder of bodily function (e.g. , cancer). Test compounds comprise both known and potential therapeutic compounds. A test compound can be determined to be therapeutic by screening using the screening methods of the present disclosure. As used herein, the term“sample ^” is used in its broadest sense. In one sense, it is meant to include a specimen or culture obtained from any source, as well as biological and environmental samples. Biological samples may he obtained from animals (including humans) and encompass fluids, solids, tissues, and gases. Biological samples include blood products, such as plasma, serum and the like. Environmental samples include environmental material such as surface matter, soil, water, and industrial samples. Such examples are not however to he construed as limiting the sample types applicable to the present disclosure.

As used herein, the term“effective amount” refers to the amount of a compound (e.g. , a compound described herein) sufficient to effect beneficial or desired results. An effective amount can be administered in one or more administrations, applications or dosages and is not limited to or intended to be limited to a particular formulation or administration route.

As used herein, the term“co-administration” refers to the administration of at least two agent(s) [e.g , ARlnci inhibitor described herein) or therapies to a subject. In some embodiments, the co-administration of two or more agents/therapies is concurrent. In other embodiments, a first agent/therapy is administered prior to a second agent/therapy. Those of skill in the art understand that the formulations and/or routes of administration of the various agents/therapies used may vary. The appropriate dosage for co-administration can be readily determined by one skilled in the art. In some embodiments, when agents/therapies are co administered, the respective agents/therapies are administered at lower dosages than appropriate for their administration alone. Thus, co-administration is especially desirable in embodiments where the co-administration of the agents/therapies lowers the requisite dosage of a known potentially harmful ( e.g ., toxic) agent(s).

As used herein, the term“pharmaceutical composition” refers to the combination of an active agent with a earner, inert or active, making the composition especially suitable for diagnostic or therapeutic use in vivo, or ex vivo.

As used herein, the temr“toxic” refers to any detrimental or harmful effects on a cell or tissue as compared to the same cell or tissue prior to the administration of the toxicant.

" Amelioration" or "ameliorate" or "ameliorating" refers to a lessening of at least one indicator, sign, or symptom of an associated disease, disorder, or condition. The severity of indicators may be determined by subjective or objective measures, which are known to those skilled in the art.

"Antisense activity" means any detectable or measurable activity attributable to the hybridization of an antisense compound to its target nucleic acid. In certain embodiments, antisense activity is a decrease in the amount or expression of a target nucleic acid or protein encoded by such target nucleic acid.

"Antisense compound" means an oligomeric compound that is capable of undergoing hybridization to a target nucleic acid through hydrogen bonding. Examples of antisense compounds include, but are not limited to, single-stranded and double -stranded compounds, such as, antisense oligonucleotides, siRNAs and shRNAs.

" Antisense inhi bition" means reducti on of target nucleic acid levels or target protein levels in the presence of an antisense compound complementary to a target nucleic acid compared to target nucleic acid levels or target protein levels in the absence of the antisense compound.

"Antisense oligonucleotide" means a single-stranded oligonucleotide having a nucleobase sequence that permits hybridization to a corresponding region or segment of a target nucleic acid.

"Base complementarity" refers to the capacity for the precise base pairing of nucleobases of an antisense oligonucleotide with corresponding nucleobases in a target nucleic acid (i.e., hybridization), and is mediated by Watson-Crick, Hoogsteen or reversed Hoogsteen hydrogen binding between corresponding nucleobases. "Bicyciic sugar moiety" means a modified sugar moiety comprising a 4 to 7 membered ring (including but not limited to a furanosyl) comprising a bridge connecting two atoms of the 4 to 7 membered ring to form a second ring, resulting in a bicyciic structure. In certain embodiments, the 4 to 7 membered ring is a sugar ring. In certain embodiments the 4 to 7 membered ring is a furanosyl. In certain such embodiments, the bridge connects the 2’-carbon and the 4'-carbon of the furanosyl.

"Oligonucleotide" means a polymer of linked nucleosides each of which can be modified or unmodified, independent one from another.

Provided herein are compositions and methods for treating cancer in particular, provided herein are compositions, methods, and uses of inhibitors of ARlncl for treating cancer.

Long non-coding RNAs (IncRNAs) are a class of transcripts with diverse and largely uncharacterized biological functions ^{1 3} . Through cross-talk with chromatin, DNA, RNA species, and proteins, IncRNAs function via chromatin remodeling, transcriptional and post- transcriptional regulation ^{4 9} . High-throughput RNA sequencing (RNA-Seq) has enabled the identification of IncRNAs with oncogenic and tumor suppressive roles, including

involvement in the pathogenesis of prostate cancer (PCa) ⁷ = ^lu . Primary PCa is often hormone-dependent and relies on signaling through the androgen receptor (AR); therefore, the majority of patients are responsive to front-line treatment with androgen deprivation therapy (ADT) ^{1 J 15} . However, approximately 20% of cases progress to an incurable stage of the disease known as castration-resistant prostate cancer (CRPC), which still critically relies on AR signaling ⁵⁶ · ¹⁷ , as evidenced by the clinical benefit afforded through the use of enzalutamide ⁵⁶ ·' ⁵ or abiraterone ^{22 24} . While substantial efforts have been undertaken to identify mechanisms of sustained AR signaling in CRPC (e.g., AR mutations, AR splice variants, and alternative activation pathways) ^{25 31} , few' studies have investigated the role of AR-regulated IncRNAs Therefore, described herein is a comprehensive RNA-Seq profiling investigation of AR-regulated, cancer-associated IncRNAs from prostate cancer cell lines and patient tissue samples. During such experiments, ARlncl w ^r as identified as a target in prostate cancer.

Accordingly, provided herein are compositions and methods for treating cancer by inhibiting the expression and/or function of ARlncl.

I. Inhibitors

In some embodiments, the ARlncl inhibitor is selected from, for example, a nucleic acid (e.g., siRNA, shRNA, miRNA or an antisense nucleic acid), a small molecule, a peptide, or an antibody.

In some embodiments, the ARlnc l inhibitor is a nucleic acid. Exemplar' nucleic acids suitable for inhibiting ARlncl (e.g., by preventing expression of ARlncl) include, but are not limited to, antisense nucleic acids and RNAi. In some embodiments, nucleic acid therapies are complementary to and hybridize to at least a portion (e.g., at least 5, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleotides) of ARlncl.

In some embodiments, compositions comprising oligomeric antisense compounds, particularly oligonucleotides are used to modulate the function of nucleic acid molecules encoding ARlncl, ultimately modulating the amount of ARlncl expressed. This is accomplished by providing antisense compounds that specifically hybridize with one or more nucleic acids encoding ARlncl. The specific hybridization of an oligomeric compound with its target nucleic acid interferes with the normal function of the nucleic acid. This modulation of function of a target nucleic acid by compounds that specifically hybridize to it is generally referred to as“antisense/’ The functions of DNA to be interfered with include replication and transcription. The functions of RNA to be interfered with include all vital functions such a , for example, translocation of the RNA to the site of protein translation, translation of protein from the RNA, splicing of the RNA to yield one or more mRNA species, and catalytic activity that may be engaged in or facilitated by the RNA. The overall effect of such interference with target nucleic acid function is decreasing the amount of ARlncl proteins in the cell.

In certain embodiments, antisense compounds have chemically modified subunits arranged in patterns, or motifs, to confer to the antisense compounds properties such as enhanced inhibitory activity, increased binding affinity for a target nucleic acid, or resistance to degradation by in vivo nucleases. Chimeric antisense compounds typically contain at least one region modified so as to confer increased resistance to nuclease degradation, increased cellular uptake, increased binding affinity for the target nucleic acid, and/or increased inhibitory activity. A second region of a chimeric antisense compound may confer another desired property e.g., serve as a substrate for the cellular endonuclease RNase H, which cleaves the RNA strand of an RNA:DNA duplex.

Antisense activity may result from any mechanism involving the hybridization of the antisense compound (e.g., oligonucleotide) with a target nucleic acid, wherein the hybridization ultimately results in a biological effect. In certain embodiments, the amount and/or activity of the target nucleic acid is modulated. In certain embodiments, the amount and/or activity of the target nucleic acid is reduced. In certain embodiments, hybridization of the antisense compound to the target nucleic acid ultimately results in target nucleic acid degradation. In certain embodiments, hybridization of the antisense compound to the target nucleic acid does not result in target nucleic acid degradation. In certain such embodiments, the presence of the antisense compound hybridized with the target nucleic acid (occupancy) results in a modulation of antisense activity. In certain embodiments, antisense compounds having a particular chemical motif or partem of chemical modifications are particularly sui ted to exploit one or more mechanisms. In certain embodiments, antisense compounds function through more than one mechanism and/or through mechanisms that have not been elucidated. Accordingly, the antisense compounds described herein are not limited by particular mechanism.

Antisense mechanisms include, without limitation, RNase H mediated antisense; RNAi mechanisms, which utilize the R.sub. iSC pathway and include, without limitation, siRNA, ssRNA and microRNA mechanisms; and occupancy based mechanisms. Certain antisense compounds may act through more than one such mechanism and/or through additional mechanisms.

In certain embodiments, antisense activity results at least in part from degradation of target RNA by RNase H. RNase H is a cellular endonuclease that cleaves the RNA strand of an RNA: DNA duplex. It is known in the art that single-stranded antisense compounds which are "DNA-like" elicit RNase H activity in mammalian cells. Accordingly, antisense compounds comprising at least a portion of DN A or DNA-like nucleosides may activate RNase H, resulting in cleavage of the target nucleic acid. In certain embodiments, antisense compounds that utilize RNase H comprise one or more modified nucleosides. In certain embodiments, such antisense compounds comprise at least one block of 1-8 modified nucleosides. In certain such embodiments, the modified nucleosides do not support RNase H activity. In certain embodiments, such antisense compounds are gapmers, as described herein. In certain such embodiments, the gap of the gapmer comprises DNA nucleosides. In certain such embodiments, the gap of the gapmer comprises DNA-like nucleosides. In certain such embodiments, the gap of the gapmer comprises DNA nucleosides and DNA-like nucleosides.

Certain antisense compounds having a gapmer motif are considered chimeric antisense compounds. In a gapmer an internal region having a plurality of nucleotides that supports RNaseH cleavage is positioned between external regions having a plurality of nucleotides that are chemically distinct from the nucleosides of the internal region. In die case of an antisense oligonucleotide having a gapmer motif, the gap segment generally serves as the substrate for endonuclease cleavage, while the wing segments comprise modified nucleosides. In certain embodiments, the regions of a gapmer are differentiated by the types of sugar moieties comprising each distinct region. The types of sugar moieties that are used to differentiate the regions of a gapmer may in some embodiments include .beta.-D- ribonucleosides, .beta.-D-deoxyribonucleosides, 2'-modified nucleosides (such 2'-modified nucleosides may include 2'-MOE and 2'-0— CH.sub.3, among others), and bicyclic sugar modified nucleosides (such bicyclic sugar modified nucleosides may include those having a constrained ethyl). In certain embodiments, nucleosides in the wings may include several modified sugar moieties, including, for example 2'-MOE and bicyclic sugar moieties such as constrained ethyl or LNA. In certain embodiments, wings may include several modified and unmodified sugar moieties. In certain embodiments, wings may include various combinations of 2'-MOE nucleosides, bicyclic sugar moieties such as constrained ethyl nucleosides or LNA nucleosides, and 2'-deoxynucleosides. Each distinct region may comprise uniform sugar moieties, variant, or alternating sugar moieties. The wing-gap-wing motif is frequently described as "X-Y-Z", where "X" represents the length of the 5 '-wing, "Y" represents the length of the gap, and "Z" represents the length of the 3'~wing. "X" and "Z" may comprise uniform, variant, or alternating sugar moieties. In certain embodiments, "X" and "Y" may include one or more 2'- deoxynucleosides. "Y" may comprise 2'-deoxynucleosides. As used herein, a gapmer described as "X-Y-Z" has a configuration such that the gap is positioned immediately adjacent to each of the 5'-wing and the 3' wing. Thus, no intervening nucleotides exist between the 5'-wing and gap, or the gap and die 3 '-wing. Any of die antisense compounds described herein can have a gapmer motif. In certain embodiments, "X" and "Z" are the same; in other embodiments they are different. In certain embodiments, "Y" is between 8 and 15 nucleosides. X, Y, or Z can be any of I, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30 or more nucleosides.

in certain embodiments, the antisense compound has a gapmer motif in which the gap consists of 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 linked nucleosides.

In certain embodiments, antisense compounds including those particularly suited for use as single -stranded RNAi compounds (ssRNA) comprise a modified S'-terminal end. In certain such embodiments, the 5'-terminal end comprises a modified phosphate moiety. In certain embodiments, such modified phosphate is stabilized (e.g., resistant to

degradation/cleavage compared to unmodified 5 '-phosphate). In certain embodiments, such 5 ^! ~terminai nucleosides stabilize the 5 '-phosphorous moiety. Certain modified 5'-terminaI nucleosides may be found in the art, for example in WO/201 1/139702

In certain embodiments, antisense compounds, including those particularly suitable for ssRNA comprise one or more type of modified sugar moieties and/or naturally occurring sugar moieties arranged along an oligonucleotide or region thereof in a defined pattern or sugar modification motif. Such motifs may include any of the sugar modifications discussed herein and/or other known sugar modifications.

in certain embodiments, the oligonucleotides comprise or consist of a region having uniform sugar modifications. In certain such embodiments, each nucleoside of the region comprises the same RNA-like sugar modification. In certain embodiments, each nucleoside of the region is a 2'-F nucleoside. In certain embodiments, each nucleoside of the region is a 2'-OMe nucleoside. In certain embodiments, each nucleoside of the region is a 2'-MOE nucleoside. In certain embodiments, each nucleoside of the region is a cEt nucleoside. In certain embodiments, each nucleoside of the region is an LNA nucleoside. In certain embodiments, the uniform region constitutes all or essentially all of the oligonucleotide. In certain embodiments, the region constitutes the entire oligonucleotide except for 1-4 terminal nucleosides.

In certain embodiments, oligonucleotides comprise one or more regions of alternating sugar modifications, wherein the nucleosides alternate between nucleotides having a sugar modification of a first type and nucleotides having a sugar modification of a second type. In certain embodiments, nucleosides of both types are RNA-like nucleosides. In certain embodiments the alternating nucleosides are selected from: 2'-OMe, 2'-F, 2'-MOE, LNA, and cEt. In certain embodiments, the alternating modifications are 2'-F and 2'-OMe. Such regions may be contiguous or may be interrupted by differently modified nucleosides or conjugated nucleosides.

In certain embodiments, the alternating region of alternating modifications each consist of a single nucleoside (i.e., the patern is (AB).sub.xA.sub.y wherein A is a nucleoside having a sugar modification of a first type and B is a nucl eoside having a sugar modification of a second type; x is 1-20 and y is 0 or 1). In certain embodiments, one or more alternating regions in an alternating motif includes more than a single nucleoside of a type.

In certain embodiments, oligonucleotides having such an alternating motif also comprise a modified 5' terminal nucleoside, such as those of formula lie or lie.

In certain embodiments, antisense compounds, including those particularly suited for use as ssRNA comprise modified temucleoside linkages arranged along the oligonucleotide or region thereof in a defined pattern or modified intemucleoside linkage motif. In certain embodiments, oligonucleotides comprise a region having an alternating intemucleoside linkage motif. In certain embodiments, oligonucleotides comprise a region of uniformly modified intemucleoside linkages. In certain such embodiments, the oligonucleotide comprises a region that is uniformly linked by phosphorothioate intemucleoside linkages. In certain embodiments, the oligonucleotide is unifonnly linked by phosphorothioate intemucleoside linkages. In certain embodiments, each intemucleoside linkage of the oligonucleotide is selected from phosphodiester and phosphorothioate. In certain

embodiments, each intemucleoside linkage of the oligonucleotide is selected from phosphodiester and phosphorothioate and at least one intemucleoside linkage is

phosphorothioate .

In certain embodiments, the oligonucleotide comprises at least 6 phosphorothioate intemucleoside linkages. In certain embodiments, the oligonucleotide comprises at least 8 phosphorothioate intemucleoside linkages. In certain embodiments, the oligonucleotide comprises at least 10 phosphorothioate intemucleoside linkages. In certain embodiments, the oligonucleotide comprises at least one block of at least 6 consecutive phosphorothioate intemucleoside linkages. In certain embodiments, the oligonucleotide comprises at least one block of at least 8 consecutive phosphorothioate intemucleoside linkages. In certain embodiments, the oligonucleotide comprises at least one block of at least 10 consecutive phosphorothioate intemucleoside linkages. In certain embodiments, the oligonucleotide comprises at least one block of at least one 12 consecutive phosphorothioate intemucleoside linkages. In certain such embodiments, at least one such block is located at the 3' end of the oligonucleotide. In certain such embodiments, at least one such block is located within 3 nucleosides of the 3' end of the oligonucleotide.

Additional modifications are described, for example, in U.S. Pat. No. 9,796,976, herein incorporated by reference in its entirety.

In some embodiments, nucleic acids are RNAi nucleic acids.“RNA interference (RNAi)” is the process of sequence-specific, post-transcriptional gene silencing initiated by a small interfering RNA (siRNA), shRNA, or microRNA (miRNA) During RNAi, the RNA induces degradation of target mRNA with consequent sequence-specific inhibition of gene expression.

In "‘RNA interference,” or“RNAi,” a“small interfering RNA” or“short interfering RNA” or“siRNA” or“short hairpin RNA” or“shRNA” molecule, or“miRNA” an RNAi (e.g., single strand, duplex, or hairpin) of nucleotides is targeted to a nucleic acid sequence of interest, for example, ARlncl.

An“RNA duplex” refers to the structure formed by the complementary' pairing between two regions of a RNA molecule. The RNA using in RNAi is“targeted” to a gene in that the nucleotide sequence of the duplex portion of tire RNAi is complementary to a nucleotide sequence of the targeted gene. In certain embodiments, the RNAi is are targeted to the sequence encoding ARlncl . In some embodiments, the length of the RNAi is less than 30 base pairs. In some embodiments, the RNA can be 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 1 1 or 10 base pairs in length. In some embodiments, the length of the RNAi is 1 to 32 base pairs in length. In certain embodiment, the length of the RNAi is 19 or 21 base pairs in length.

In some embodiments, RNAi comprises a hairpin structure (e.g., shRNA). In addition to the duplex portion, the hairpin structure may contain a loop portion positioned between the two sequences that fonn the duplex. Tire loop can ar' in length. In some embodiments the loop is 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26 or 27 nucleotides in length. In certain embodiments, the loop is 18 nucleotides in length. The hairpin structure can also contain 3' and/or 5' overhang portions. In some embodiments, the overhang is a 3' and/or a 5' overhang 0, 1, 2, 3, 4 or 5 nucleotides in length.

"miRNA" or "miR" means a non-coding RNA between 18 and 25 nucleobases in length which hybridizes to and regulates tire expression of a coding RNA. In certain embodiments, a miRNA is the product of cleavage of a pre-miRN A by the enzyme Dicer. Examples of miRNAs are found in the miRNA database known as miRBase

As used herein, Dicer-substrate RNAs (DsiRNAs) are chemically synthesized asymmetric 25-mer/27-mer duplex RNAs that have increased potency in RNA interference compared to traditional RNAi. Traditional 21-mer RNAi molecules are designed to mimic Dicer products and therefore bypass interaction with the enzyme Dicer. Dicer has been recently shown to be a component of RISC and involved with entry of the RNAi into RISC. Dicer-substrate RNAi molecules are designed to be optimally processed by Dicer and show increased potency by engaging this natural processing pathway. Using this approach, sustained knockdown has been regularly achieved using sub-nanomolar concentrations. (U.S. Pat. No. 8,084,599; Kim et ah, Nature Biotechnology 23:222 2005; Rose et al., Nucleic Acids Res., 33:4140 2005).

The transcriptional unit of a“shRNA” is comprised of sense and antisense sequences connected by a loop of unpaired nucleotides. shRNAs are exported from the nucleus by Exportm-5, and once in the cytoplasm, are processed by Dicer to generate functional RNAi molecules.“miRNAs” stem-loops are comprised of sense and antisense sequences connected by a loop of unpaired nucleotides typically expressed as part of larger primary transcripts (pri-miRNAs), which are excised by the Drosha-DGCR8 complex generating intermediates known as pre-miRNAs, which are subsequently exported from the nucleus by Exportin-5, and once in the cytoplasm, are processed by Dicer to generate functional miRNAs or siRNAs.

“Artificial miRNA” or an“artificial miRNA shuttle vector”, as used herein interchangeably, refers to a primary miRNA transcript that has had a region of the duplex stem loop (at least about 9-20 nucleotides) which is excised via Drosha and Dicer processing replaced with the siRNA sequences for the target gene while retaining the structural elements within the stem loop necessary for effective Drosha processing. The term“artificial” arises from the fact the flanking sequences (e.g., about 35 nucleotides upstream and about 40 nucleotides downstream) arise from restriction enzyme sites within the multiple cloning site of the RNAi. As used herein the term“miRNA” encompasses both the naturally occurring miRNA sequences as well as artificially generated miRNA shuttle vectors. The RNAi can be encoded by a nucleic acid sequence, and the nucleic acid sequence can also include a promoter. The nucleic acid sequence can also include a polyadeny ation signal. In some embodiments, the polyadenylation signal is a synthetic minimal polyad n certain embodiments, provided herein are compounds comprising a modified oligonucleotide consisting of 12 to 30 linked nucleosides and comprising a nucleobase sequence comprising a portion of at least 8, at least 10, at least 12, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19, or at least 20 contiguous nucleobases complementary to an equal length portion of ARlncl .

In some embodiments, hybridization occurs between an antisense compound disclosed herein and an ARlncl nucleic acid. The most common mechanism of hybridization involves hydrogen bonding (e.g , Watson-Criek, Hoogsteen or reversed Hoogsteen hydrogen bonding) between complementary nucleobases of the nucleic acid molecules.

Hybridization can occur under varying conditions. Stringent conditions are sequence- dependent and are determined by the nature and composition of the nucleic acid molecules to be hybridized.

An antisense compound and a target nucleic acid are complementary to each other when a sufficient number of nucleobases of the antisense compound can hydrogen bond with the corresponding nucleobases of the target nucleic acid, such that a desired effect will occur (e.g., antisense inhibition of a target nucleic acid, such as an ARlncl nucleic acid).

Non-complementary nucleobases between an antisense compoimd and an ARlncl nucleic acid may be tolerated provided that the antisense compound remains able to specifically hybridize to a target nucleic acid. Moreover, an antisense compound may hybridize over one or more segments of an ARLNC1 nucleic acid such that intervening or adjacent segments are not involved in the hybridization event (e.g., a loop structure, mismatch or hairpin structure).

In certain embodiments, the antisense compounds provided herein, or a specified portion thereof, are, or are at least, 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% complementary _' to an ARlncl nucleic acid, a target region, target segment, or specified portion thereof. Percent complementarity of an antisense compound with a target nucleic acid can be determined using routine methods.

For example, an antisense compoimd in which 18 of 20 nucleobases of the antisense compound are complementary to a target region, and would therefore specifically hybridize, would represent 90 percent complementarity. In this example, the remaining

noncomplementary nucleobases may be clustered or interspersed with complementary' nucleobases and need not be contiguous to each other or to complementary rmcieobases. As such, an antisense compound which is 18 nucleobases in length having 4 (four)

noncomplementary nucleobases which are flanked by two regions of complete

complementarity with the target nucleic acid would have 77.8% overall complementarity with the target nucleic acid and would thus fall within the scope of tire present invention. Percent complementarity of an antisense compound with a region of a target nucleic acid can he determined routinely using BLAST programs (basic local alignment search tools) and PowerBLAST programs known in the art (Altschul et ah, J. Mol Biol., 1990, 215, 403 410; Zhang and Madden, Genome Res., 1997, 7, 649 656). Percent homology, sequence identity or complementarity, can be determined by, for example, the Gap program (Wisconsin Sequence Analysis Package, Version 8 for Unix, Genetics Computer Group, University Research Park, Madison Wis.), using default settings, which uses the algorithm of Smith and Waterman (Adv. Appl. Math., 1981, 2, 482 489).

In certain embodiments, the antisense compounds provided herein, or specified portions thereof, are fully complementary (i .e., 100% complementary) to a target nucleic acid, or specified portion thereof. For example, an antisense compound may be fully complementary to an Alncl nucleic acid, or a target region, or a target segment or target sequence thereof. As used herein, "fully complementary" means each nucleobase of an antisense compound is capable of precise base pairing with the corresponding nucleobases of a target nucleic acid. For example, a 20 nucleobase antisense compound is fully

complementary to a target sequence that is 400 nucleobases long, so long as there is a corresponding 20 nucleobase portion of the target nucleic acid that is fully complementary to the antisense compound. Fully complementary can also be used in reference to a specified portion of the first and/or the second nucleic acid. For example, a 20 nucleobase portion of a 30 nucleobase antisense compound can be "fully complementary _' " to a target sequence that is 400 nucleobases long. The 20 nucleobase portion of the 30 nucleobase oligonucleotide is fully complementary' to the target sequence if the target sequence has a corresponding 20 nucleobase portion wherein each nucleobase is complementary to the 20 nucleobase portion of the antisense compound. At the same time, the entire 30 nucleobase antisense compound may or may not be fully complementary to the target sequence, depending on whether the remaining 10 nucleobases of the antisense compound are also complementary to the target sequence.

The location of a non-complementary nucleobase may be at the 5' end or 3’ end of the antisense compound. Alternatively, the non-complementary' nucleobase or nucleobases may be at an internal position of the antisense compound. When two or more non -complementary nucleobases are present, they may be contiguous (i.e., linked) or non-contiguous. In one embodiment, a non-complementary nudeobase is located in the wing segment of a gapmer anti sense ol igonucl eotide .

In certain embodiments, antisense compounds that are, or are up to 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleobases in length comprise no more than 4, no more than 3, no more than 2, or no more than 1 non-complementary nucleobase(s) relative to a target nucleic acid, such as an ARlncl nucleic acid, or specified portion thereof.

In certain embodiments, antisense compounds that are, or are up to 12, 13, 14, 15, 16,

17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleobases in length comprise no more than 6, no more than 5, no more than 4, no more than 3, no more than 2, or no more than 1 non-complementary nucleobase(s) relative to a target nucleic acid, such as an Alncl nucleic acid, or specified portion thereof.

The antisense compounds provided herein also include those which are

complementary to a portion of a target nucleic acid. As used herein, "portion" refers to a defined number of contiguous (i.e. linked) nucleobases within a region or segment of a target nucleic aad. A "portion" can also refer to a defined number of contiguous nucleobases of an antisense compound. In certain embodiments, the antisense compounds, are complementary to at least an 8 nudeobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 12 nudeobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 15 nudeobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least an 18 nudeobase portion of a target segment. Also contemplated are antisense compounds that are complementary to at least a 9, 10, 11, 12, 13, 14, 15, 16, 17,

18, 19, 20, or more nudeobase portion of a target segment, or a range defined by any two of these values.

The present disclosure contemplates the use of any genetic manipulation for use m modulating the expression of ARlncl . Examples of genetic manipulation include, but are not limited to, gene knockout (e.g., removing the ARlncl gene from the chromosome using, for example, recombination), expression of antisense constructs with or without inducible promoters, and the like. Delivery of nucleic acid construct to cells in vitro or in vivo may be conducted using any suitable method. A suitable method is one that introduces the nucleic acid construct into the cell such that the desired event occurs (e.g., expression of an antisense construct). Introduction of molecules carrying genetic information into cells is achieved by any of various methods including, but not limited to, directed injection of naked DNA constructs, bombardment with gold particles loaded with said constructs, and macromolecule mediated gene transfer using, for example, liposomes, biopolymers, and the like. Exemplar} _' methods use gene delivery vehicles derived from viruses, including, but not limited to, adenoviruses, retroviruses, vaccinia viruses, and adeno-associated viruses. Because of the higher efficiency as compared to retroviruses, vectors derived from adenoviruses are the preferred gene deliver}' vehicles for transferring nucleic add molecules into host cells in vivo. Adenoviral vectors have been shown to provide very efficient in vivo gene transfer into a variety of solid tumors in animal models and into human solid tumor xenografts in immune-deficient mice. Examples of adenoviral vectors and methods for gene transfer are described in PCX publications WO 00/12738 and WO 00/09675 and U.S. Pat. Appl. Nos. 6,033,908, 6,019,978, 6,001,557, 5,994,132, 5,994,128, 5,994,106, 5,981,225, 5,885,808, 5,872,154, 5,830,730, and 5,824,544, each of which is herein incorporated by reference in its entirety.

Vectors may be administered to subject in a variety of ways. For example, in some embodiments of the present disclosure, vectors are administered into tumors or tissue associated with tumors using direct injection. In oilier embodiments, administration is via tire blood or lymphatic circulation (See e.g., PCX publication 1999/02685 herein incorporated by reference in its entirety). Exemplary dose levels of adenoviral vector are preferably 10 ^s to 10 ^u vector particles added to the perfusate.

In some embodiments, CRISPR/Cas9 systems are used to delete or knock out genes. Clustered regularly interspaced short palindromic repeats (CRISPR) are segments of prokaryotic DNA containing short, repetitive base sequences. These play a key role in a bacterial defence system, and form the basis of a genome editing technology known as CRISPR/Cas9 that allows permanent modification of genes within organisms.

In some embodiments, the present disclosure provides antibodies that inhibit ARlncl. Any suitable antibody (e.g., monoclonal, polyclonal, or synthetic) may be utilized m the therapeutic methods disclosed herein. In some embodiments, the antibodies are humanized antibodies. Methods for humanizing antibodies are well known in the art (See e.g., U.S Patents 6,180,370, 5,585,089, 6,054,297, and 5,565,332; each of which is herein incorporated by reference).

In some embodiments, candidate ARlncl inhibitors are screened for activity (e.g., using the methods described herein or another suitable assay). The present disclosure further provides pharmaceutical compositions (e.g., comprising the compounds described above). The pharmaceutical compositions of the present disclosure may be administered in a number of ways depending upon whether local or systemic treatment is desired and upon the area to be treated . Administration may be topical (including ophthalmic and to mucous membranes including vaginal and rectal delivery), pulmonary (e.g., by inhalation or insufflation of powders or aerosols, including by nebulizer; intratracheal, intranasal, epidermal and transdermal), oral or parenteral. Parenteral administration includes intravenous, intraarterial, subcutaneous, intraperitoneal or intramuscular injection or infusion; or intracranial, e.g., intrathecal or intraventricular, administration.

Pharmaceutical compositions and formulations for topical adm inistration may include transdermal patches, ointments, lotions, creams, gels, drops, suppositories, sprays, liquids and powders. Conventional pharmaceutical carriers, aqueous, powder or ody bases, thickeners and the like may be necessary or desirable.

Compositions and formulations for oral administration include powders or granules, suspensions or solutions in water or non-aqueous media, capsules, sachets or tablets.

Thickeners, flavoring agents, diluents, emulsifiers, dispersing aids or binders may be desirable.

Compositions and formulations for parenteral, intrathecal or intraventricular administration may include sterile aqueous solutions that may also contain buffers, diluents and other suitable additives such as, but not limited to, penetration enhancers, carrier compounds and other pharmaceutically acceptable carriers or excipients.

Pharmaceutical compositions of the present disclosure include, but are not limited to, solutions, emulsions, and liposome -containing formulations. These compositions may be generated from a variety of components that include, but are not limited to, preformed liquids, self-emulsifying solids and self-emulsifying semisolids.

Hie pharmaceutical formulations of the present disclosure, which may conveniently be presented in unit dosage form, may be prepared according to conventional techniques well known in the pharmaceutical industry. Such techniques include the step of bringing into association the active ingredients with the pharmaceutical carrier(s) or excipient(s). In general the formulations are prepared by uniformly and intimately bringing into association the active ingredients with liquid carriers or finely divided solid carriers or both, and then, if necessary, shaping the product. The compositions of the present disclosure may be formulated into any of many possible dosage forms such as, but not limited to, tablets, capsules, liquid syrups, soft gels, suppositories, and enemas. The compositions of the present disclosure may also he formulated as suspensions in aqueous, non-aqueous or mixed media. Aqueous suspensions may further con tain substances that increase the viscosity of the suspension including, for example, sodium carboxymethylceiluiose, sorbitol and/or dextran. The suspension may also contain stabilizers.

Agents that enhance uptake of oligonucleotides at the cellular level may also be added to the pharmaceutical and other compositions of the present disclosure. For example, cationic lipids, such as lipofectin (U.S. Pat. No. 5,705, 188), cationic glycerol derivatives, and polycationic molecules, such as polylysine (WO 97/30731), also enhance the cellular uptake of oligonucleotides.

The compositions of the present disclosure may additionally contain other adjunct components conventionally found in pharmaceutical compositions. Thus, for example, the compositions may contain additional, compatible, pharmaceutical ly-active materials such as, for example, antipruritics, astringents, local anesthetics or anti-inflammatory agents, or may contain additional materials useful in physically formulating various dosage forms of the compositions of the present di sclosure, such as dyes, flavoring agents, preservatives, antioxidants, opacifiers, thickening agents and stabilizers. However, such materials, when added, should not unduly interfere with the biological activities of the components of tire compositions of the present disclosure. The formulations can be sterilized and, if desired, mixed with auxiliary agents, e.g. , lubricants, preservatives, stabilizers, wetting agents, emulsifiers, salts for influencing osmotic pressure, buffers, colorings, flavorings and/or aromatic substances and the like which do not deleteriously interact with the nucleic acid(s) of the formulation.

Dosing is dependent on severity and responsiveness of the disease state to be treated, with the course of treatment lasting from several days to several months, or until a cure is effected or a diminution of the disease state is achieved. Optimal dosing schedules can be calculated from measurements of drug accumulation in the body of the patient. Tire administering physician can easily determine optimum dosages, dosing methodologies and repetition rates. Optimum dosages may vary depending on the relative potency of individual oligonucleotides, and can generally be estimated based on ECS 0s found to be effecti ve in in vitro and in vivo animal models or based on the examples described herein. In general, dosage is from 0.01 pg to 100 g per kg of body weight, and may be given once or more daily, weekly, monthly or yearly. The treating physician can estimate repetition rates for dosing based on measured residence times and concentrations of the drug in bodily fluids or tissues. Following successful treatment, it may be desirable to have the subject undergo maintenance therapy to prevent the recurrence of the disease state, wherein the oligonucleotide is administered in maintenance doses, ranging from 0.01 pg to 100 g per kg of body weight, once or more daily, to once every 20 years.

II. Methods of treating cancer

Provided herein are methods of treating cancer (e.g., prostate cancer). In some embodiments, a sample of tumor or cancerous tissue from the subject is first tested for expression of ARlnel . In some embodiments, treatment is administered to individuals with expression of ARlnc 1 and/or individuals with levels of expression of ARlnc 1 greater than the levels in non-cancerous tissue. In some embodiments, samples of tumor or cancer tissue are tested during treatment in order to determine whether or not to continue treatment.

In some embodiments, the compounds and pharmaceutical compositions described herein are administered in combination with one or more additional agents, treatment, or interventions (e.g., agents, treatments, or interventions useful in the treatment of cancer).

In some embodiments, ARlnel inhibitors are co-administered with an anti-cancer agent (e.g., chemotherapeutic). The present disclosure is not limited by type of anti-cancer agent co-administered.

The following examples are provided in order to demonstrate and further illustrate certain preferred embodiments and aspects of the present disclosure and are not to be construed as limiting the scope thereof.

Example 1

Methods

Cell lines. Cell lines were purchased from the American Type Culture Collection (ATCC) and maintained using standard media and conditions. VCaP cells were maintained in DMEM (Invitrogen) supplemented with 10% fetal bovine serum (FBS). LNCaP cells were maintained in RPMI 1640 (Invitrogen) supplemented with 10% FBS. MDA-PCa-2b cells were maintained in ATCC-formulated F-12K medium, supplemented with 20% FBS, 25 ng/ml cholera toxin, 10 ng/m! mouse epidermal growth factor, 100 pg/ml hydrocortisone, 0.005 mM phosphoethanolamine, 45nM selenous acid, and 0.005 mg/ml bovine insulin. All cell lines were grown at 37°C in 5% CO2 cell culture incubators, genotyped by DNA fingerprinting analysis, and tested for mycoplasma infection ever ' two weeks. All cell lines used in this study were mycoplasma-negative.

DHT treatment was performed to identify AR-regulated genes. DHT was purchased from Sigma-Aldrich and used at a final concentration of 10 11M. VCaP and LNCaP cells were grown in charcoal -stripped serum containing media for 48 hours and then stimulated with 10 nM DHT for six or 24 hours.

RNA-Seq. Total RNA was extracted from LNCaP and VCaP cells following DHT treatment using the miRNeasy kit (QIAGEN). RNA quality' was assessed using the Agilent Bioanalyzer. Each sample was sequenced using the Illumina HiSeq 2000 (with a 100-nt read length) according to published protocols ⁵² .

RNA-Seq data analysis to identify AR-regulated genes. RNA-Seq data were analyzed as previously described ⁵³ . Briefly, the strand-specific paired-end reads were inspected for sequencing and data quality (e.g. insert size, sequencing adapter contamination, rRNA content, sequencing error rate). Libraries passing QC vrere trimmed of sequencing adapters and aligned to the human reference genome, GRCh38 Expression was quantified at the gene level using the“intersection non-empty” mode ⁵⁴ as implemented in featureCounts ⁵⁵ using the Gencode v22 ⁵⁶ and/or MiTranscriptome assemblies ¹⁰ . All pairwise differential expression analyses were carried out using the voom-limma approach ⁵⁷ · ⁵⁸ with all default parameters. Relative expression levels (FPKMs, fragments per kilobase of transcript per million mapped reads) 'ere normalized for differences in sequencing depth using scaling factors obtained from the calcNormFactors (default parameters) function from edgeil ⁵⁹ .

AR-regulated genes (ARGs) were identified from expression data of VCaP and LNCaP cells treated with DHT after six and 24 hours using three linear models: separate models for each of the cell lines treating the two time -points as biological replicates, and a merged model with all treated samples as replicates. ARGs were defined as genes that were significant (P value < 0.1 and absolute log fold-change > 2) in both separate models and/or the merged model .

Identification of prostate cancer associated protein-coding genes and IncRNAs. Raw RNA-Seq data for primary and metastatic patients were obtained from the TCGA/PRAD and PCF/SU2C projects, respectively. External transcriptome samples were re-analyzed using in-house pipelines (see above) to facilitate direct comparisons of expression levels and identification of DEGs. Pan-cancer analyses based on the MiTranscriptome assembly ⁵⁰ were leveraged as FPKMs and enrichment scores (SSEA) computed as part of that project. To visualize data, fold changes were computed relative to median expression levels estimated across the combined (normal, primary, metastat ) cohorts and subjected to unsupervised hierarchical clustering separately within each cohort. Tissue lineage (prostate) and prostate cancer-specific genes were identified using the sample set enrichment analysis (SSEA) method as previously described ¹⁰ . Briefly, the SSEA test was used to determine whether each gene was significantly associated with a set of samples (e.g. prostate cancer), or cancer progression in a given lineage (e.g. prostate normal to prostate cancer). The genes were ranked according to their strength of association.

On comine concept analysis of the ARlncl signature. Genes with expression levels significantly correlated with ARlncl w¾re separated into positively and negatively correlated gene lists. These two lists were then imported into Oncomine as custom concepts and queried for association (similarity) with other prostate cancer concepts housed in Oncomine. All the prostate cancer concepts with odds ratio> 2.0 and p-va!ue <1 ^c 10 ^-4 were selected. For simplicity, top concepts (based on odds ratios) were selected for representation. We exported these results as the nodes and edges of a concept association network and visualized the network using Cytoscape version 3.3.0. Node positions were computed using the Edge- weighted force directed layout in Cytoscape using the odds ratio as the edge weight. Node positions were subtly altered manually to enable better visualization of Mode labels ⁶⁰ .

Chromatin immunoprecipitation (ChlP)-Seq data analysis, ChIP-Seq data from published external and in-house data sets, GSE56288 and GSE55064, were reanalyzed using a standard pipeline. Briefly, groomed reads (vendor QC, adapter removal) w¾re aligned to the GRCh38 reference genome using STAR settings that disable spliced alignment:

outFilterMismatchNoverLmax: 0.05, outFilterMatchNmin: 16, outFilterScoreMinOverLread: 0, outFilterMatchNminOverLread: 0, alignlntronMax: 1 . Improperly paired alignments and non-primary alignments were discarded. Peaks were called using MACS2 (cailpeak—broad -- qvalue 0.05—broad-cutoff 0.05 and cailpeak—call-summits— qvalue 0.05) ⁶² and Q (~n !OOOOO) ⁶⁷ . ChIP enrichment plots were computed from alignment coverage files (BigWig ⁶³ ) as trimmed (trim=0.05) smooth splines (spar=0.05). The baseline (non-specific) ChIP signal w ^r as estimated from genomic windows furthest from the center of the queried region (peak summit, transcription start site) and subtracted from each signal before plotting.

AR binding motif search. Unsupervised motif search was carried out using

MEME ⁵⁹ . For each AR ChIP-Seq dataset, the 10,000 most significant AR-binding sites were identified, pruned of likely artifacts, and reduced ⁶⁴ to a set of most Significant, recurrent“uni” AR peaks. DNA sequences (GRch38) from the uni-peak regions overlapping promoters (5 kb upstream, 1 kb downstream of the assembled or known TSS) of ARGs were used as input to MEME (default parameters).

ChIP-qPCR analysis. AR ChIP was performed following a previous protocol ³² . Antibodies: AR, Millipore Cat# 06-680; FOXA1, Thermo Fisher Cat# PA5-27157; NKX3-1, CSX Cat# 83700S.) Quantitative PCR (qPCR) analysis was performed using primers listed in Table 1. Primers targeting CYP2B7 promoter were purchased from CST, Cat #84846

RNA in situ hybridization (RNA ISH) on tissue microarray. In situ hybridization assays were performed on tissue microarray sections from Advanced Cell Diagnostics, Inc. as described previously ⁷ . In total, 133 tissue samples were included, including 11 from benign prostate, 85 from localized prostate cancer, and 37 from metastatic prostate cancer. ARlncl ISH signals were examined in morphologically- tact cells and scored manually by a study, using a previously described expression value scoring system ⁶⁵ . For each tissue sample, the ARLNC1 product score was averaged across evaluable TMA tissue cores. Mean ARLNC1 product scores were plotted in Fig. 2e.

RACE. 5 ^‘ and 3’ RACE were performed to determine the transcriptional start and termination sites of ARlncl, using the GeneRacer RLM-RACE kit (Invitrogen), according to the manufacturer’s instructions.

Northern blot analysis. To validate the presence of ARlncl in MDA-PCa-2b ceils, Northern blotting was performed using the NorthemMax Kit (Ambion) following the manufacturer’s protocol. Briefly, 20 mg of total RNA was extracted from MDA-PCa-2b or DU145 cells, denatured with formaldehyde loading dye solution for 10 minutes at 70°C, and separated on a 1% agarose formaldehyde gel. The RNA w¾s then transferred to nylon membrane (Roche), cross-linked to the membrane (UV Stratalinker 1800; Stratagene), and the membrane was pre-hybridized in ultrahybridization solution at 68°C for 1 hour.

Hybridization followed at 68°C overnight with the ARlncl- specific biotinylated nboprobe added to the ultrahybridization solution. The membrane was washed, and the bound biotinylated probe was detected with the CDP-Star Chemiluminescent Substrate (Sigma- Aldrich). For the synthesis of ARlncl -specific biotinylated riboprobe, biotin was randomly incorporated into the ARlncl antisense RNA upon transcription using ARlncl full-length PCR product as template (Roche). The primer sequences used for generating the probes are given in Table 1 . RNA isolation and cDNA synthesis. Total RNA from cell lines was isolated using QIAzol Lysis reagent (QIAGEN) and miRNeasy kit (QIAGEN) with DNase I digestion according to manufacturer’s instructions. cDNA was synthesized using Superscript III (Invitrogen) and random primers (Invitrogen).

qRT-PCR analysis. Relative RNA levels determined by qRT -PCR were measured on an Applied Biosystems 7900HT Real-Time PCR System, using Power SYBR Green MasterMix (Applied Biosystems). All of the primers were obtained from integrated DNA Technologies (IDT), and gene-specific sequences are listed in Table 1. GAPDH , HMBS, or ACTB were used as internal controls for quantification of gene targets. Tie relative expression of RNAs was calculated using AACt method.

Cytoplasmic and nuclear RNA purification Cytoplasmic and nuclear fractionation was performed using the NE-PER nuclear extraction kit (Thermo Scientific) according to manufacturer’s instructions. RNA was extracted using the previously mentioned protocol. siRNA-mediated knockdown. siRNA oligonucleotides targeting ARLNC1, AR, FOXA1 BRPJ4 NKX3-1, LSD l, IRFl POU1 FI or EZH2 and a non -targeting siRNA were purchased from Dhamiacon. (si-AR-pool, Cat# L-003400-00-0005; si -FOXAJ, Cat# LU- 010319-00-0005; si -BRD4, Cat# LU-004937-00-0002; si -NKX3-1, Cat# LU-015422-00- 0005; si-LSDl, Cat# LU-009223-00-0002; si -IRFl, Cat# LU-011704-00-0005; si -POU1FL Cat# LU-012546-00-0005; ύ-EZH2, Cat# L-004218-00-0005; si-NT, Cat# D-001810-01-05.) siRNA sequences for ARLNC1 knockdown are listed in Table 1. For AR knockdown, two more siRNAs were purchased from Life Technologies (#HSS 179972, #HSS179973).

Transfections with siRNA (50 nM) were performed with Lipofectamine RNAiMAX according to the manufacturer’s instructions. RNA and protein were harvested for analysis 72 hours after transfection.

ASO-mediated knockdown. Antisense oligos targeting ARlnci were obtained from Tonis Pharmaceuticals. Transfections with ASOs (50 nM) were performed with

Lipofectamine RNAiMAX according to the manufacturer’s instructions. RNA and protein were harvested for analysis 72. hours after transfection.

Gene expression profiling. Total RNA was extracted following the aforementioned protocol. RNA integrity was assessed using the Agilent Bioanalyzer. Microarray analysis was carried out on the Agilent Whole Human Oligo Microarray platform, according to the manufacturer’s protocol. siRNA-mediated knockdown experiments were ran in technical triplicates, comparing knockdown samples treated with two independent ARlnci siRNAs to samples treated with non-targeting control siRNA. ASO-mediated knockdown experiments were run in technical replicates, comparing knockdown samples treated with two ARlncl ASOs to samples treated with non-targeting control. An AR signature was generated using MDA-PCa-2b cells treated with 10 nM DHT, in technical triplicates.

Analysis of Agilent 44k microarrays was carried out using limma and included background subtraction (bc.method= ^’ ¾alf olT ci 100) and within-array normalization (method ^: =”loess”). Between array quantile normalization of average expression le vels (but not log-fold changes) was performed using the function normalizeBetweenArrays

(method=”Aquantile”). Control probes and probes with missing values were excluded from further analyses. Probes were annotated to Gencode v22 genes using the mapping

downloaded from Ensembl (efg agilent wiiolegenome 4x44k v2). Probes originally annotated as AK093002 were used to detect ARlncl . Differentially-expressed genes following ARlncl knock-down in MDA-PCA-2b cells were identified from triplicate biological repeats using adj.P.Val < 0.1 and absolute log fold-change > 0.6 cut-offs.

Consensus targets of ARlncl knockdown using siRNA and ASOs were identified using a merged linear model (all 10 samples treated replicates) and a P value < 0.001 cut-off.

Gene Set Enrichment Analysis. Enrichment analyses for custom and

experimentally -derived signatures (i.e. AR targets, genes up- and down-regulated following DHT treatment) were carried out using the nonparametrie GSEA software with all default settings. For Gene Ontology (GO) term enrichment, we applied the parametric randomSet ⁶⁶ enrichment statistic to voom-limma estimated fold-changes (see above).

Overexpression of ARlncl. Full-length ARlncl was amplified from MDA-PCa-2b cells and cloned into the pCDH clone and expression vector (System Biosciences). Insert sequences w¾re validated by Stinger sequencing at the University of Michigan Sequencing Core. Full-length ARlncl sequence is listed in Table 2.

Single molecule fluorescent in situ hybridization (smFISH). smFISH and image analysis was performed as described ⁶⁷ · ⁶⁸ · Probe sequences targeting AR, ARlnd, PC A TI, DANCR, EZH2 and FOXA1 were designed using the probe design software in

https://www.biosearchtech.com/stellaris-desxgner and are listed in Table 3. TERRA probes were designed as described ⁶⁹ . Other probes were purchased directly from the LGC-Biosearch . U2-OS cells were seeded in 6-well dishes and transfected with ARlncl alone or in combination with AR expression vector using Fugene-HD (Promega) according to the manufacturer’s protocol. Cells were incubated for 24 hours, reseeded into 8-well chambered coverglasses, and formaldehyde-fixed for smFISH (as described above) after 24 hours.

smFISH was carried out according to the above protocol. Number of molecules within large foci was calculated based on the scaled intensity of individual molecules of the appropriate RNA.

RNA in vitro transcription. Linearized DNA templates for full-length ARlncl, ARlncl fragments, ARlncl deletion, antisense ARlncl, LacZ, SCHLAP1-AS, THOR, and .di?- 3 ^' UTR-1-980 were synthesized using T7-containing primers. Sequences were confirmed by Sanger sequencing at the University of Michigan Sequencing Core. In vitro transcription assays were performed with T7 RNA polymerase (Promega) according to the manufacturer’s instructions. For BrU-!abeled RNA synthesis, 5-Bromo-UTP was added to the incubation system. At the end of transcription, DNA templates were removed by Turbo DNase

(ThermoFisher), and RNA was recovered using RNA Clean and Concentrator Kit (Promega). RNA size and quality was further confirmed by the Agilent Bioanalyzer.

RNA-RNA in vitro interaction assay. For each interaction assay, 25 mΐ of Protein A/G Magnetic Beads (Pierce) were washed twice with RIP Wash Buffer (Millipore, Cat# CS203177) before incubating with BrU antibody for one hour at room temperature. After antibody conjugation, beads were washed twice with RIP Wash Buffer and then resuspended in Incubation Buffer containing RIP Wash Buffer, 17.5 mM EDTA (Millipore, Cat#

CS203175), and RNase Inhibitor (Millipore, Cat# CS203219). For validation of ARlncl and AR 3’UTR binding in vitro , equal amounts (5 pinol) of BrU-labeled RNAs (ARlncl , A Rlnc l - AS, LacZ, SCHLAP 1 -AS, THOR) were incubated with beads in Incubation Buffer for two hours at 4°C. Following incubation, 2.5 pmol of AR 3’UTR-l-980 RNA fragment w¾s added into individual tubes and incubated overnight at 4°C. After incubation, beads were washed six times with RIP Wash Buffer To recover RNA, beads were digested with proteinase K buffer containing RIP Wash Buffer, 1% SDS (Millipore, Cat# CS203174), and 1.2 pg/pL proteinase K (Millipore, Cat# CS203218) at 55°C for 30 minutes with shaking. After digestion, RNA was extracted from supernatant using the miRNeasy kit (QIAGEN), and reverse transcription was performed using the Superscript III system (Invitrogen). The amount oiAR 3’ UTR- 1-980 recovered in each interaction assay was quantified by qPCR analysis. Data were normalized to ARlncl -AS control, using ACt method.

To identify the sites in ARlncl that mediate interaction with AR 3’UTR, an RNA- RNA interaction assay was performed following the aforementioned protocol, using BrU- labeled RNAs: ARlncl, ARlncl -AS, ARlncl fragments (ARlncl ARlncl- 1301-2786, ARlncl '-1-700, ARlncl- 701-1300), and ARlncl deletion (Ai?/«c/-del-701 -1300).

To further validate the interaction, antisense oligos blocking the interaction sites (blocking ASO, Ionis Pharmaceuticals) were used. In-vitro interaction assays between ARlncl and AR 3’UTR were performed following the aforementioned protocol, with the addition of control ASO or blocking ASO pool. Data were normalized to the control ASO, using the ACt method.

RNA stability assay. LNCaP cells were treated with 5 pg/mL of actinomycin D for various times as indicated in the figure. RNA was extracted at different time points using QIAzol Lysis reagent (QLAGEN) and the miRNeasy kit (Q1AGEN). Real-time RT-PCR was carried out as described above. RNA half-life (ti/2) was calculated by linear regression analysis (GraphPad Prism ^® software).

Ceil proliferation assay. To test the effects of knocking down ARlncl on cell proliferation, MDA-PCa-2b or LNCaP ceils were seeded into 24-well plates in quadruplicate and allowed to attach. Cells were then transfected with siRNAs or ASOs using Lipofectamine RNAiMAX. Cell proliferation was determined by IncuCyte live-cell imaging system (Essen Biosciences).

Apoptosis analysis. MDA-PCa-2b, LNCa,P and PNT2 cells were grown in 6-well plates and transfected with nonspecific siRNA or siRNAs targeting ARlncl . Apoptosis analysis as performed 48 hours after transfection, using Dead Ceil Apoptosis Kit

(Molecular Probes #¥13241) according to manufacturer’s instructions.

Immunoblot analysis. Cells were lysed in RIP A lysis and extraction buffer (Thermo Scientific #89900) supplemented with protease inhibitor cocktail (ROCHE #1 1836170001). Protein concentrations were quantified using the DC protein assay (BIO-RAD), and protein lysates were boiled in sample buffer. Protein extracts were then loaded and separated on SDS-PAGE gels. Blotting analysis was performed with standard protocols using

polyvinylidene difluoride (PVDF) membrane (GE Healthcare). Membranes w'ere blocked for 60 minutes in blocking buffer (5% milk in a solution of 0.1% Tween-20 m Tris-buffered saline (TBS-T)) and then incubated overnight at 4°C with primary antibody. After three washes with TBS-T, membranes were incubated with HRP -conjugated secondary antibody. Signals were visualized with an enhanced chemiluminescence system as described by the manufacturer (Thermo Scientific Pierce ECL Western Blotting Substrate). Primary antibodies used in this study were: Androgen Receptor (1 : 1000 dilution, Millipore, #06-680, rabbit), GAPDH (1 :5000 dilution, Cell Signaling, #3683, rabbit), PSA (1 :5000 dilution, Dako, #AG562, rabbit), and cleaved PARP (1: 1000 dilution, Cell Signaling, #9542, rabbit)

Androgen receptor reporter gene assay. Dual luciferase reporter assays were performed using Cigna! Androgen Receptor Reporter Kit (Qiagen) according to the manufacturer’s instructions. Briefly, MDA-PCa-2b cells and LNCaP cells were co- transfected with siRNAs (nonspecific, targeting AR or ARlncl) and reporter vectors (negative control or AR reporter), using Lipofectamine 2000 transfection reagent (Thermo Fisher Scientific) 40 hours after transfection, DHT (or ethanol vehicle control) was added to induce AR signaling. The Dual Luciferase assay was conducted eight hours after DHT stimulation, using the Dual Luciferase Reporter Assay System from Promega (Cat #1910). Reporter activity was analyzed based on ratio of Firefly /Renilla to normalize for cell number and transfection efficiency.

In vivo experiments. For tumor generation with shRNA-mediated knockdown, shRNA targeting ARLNC1 was cloned in pSIHl-Hl -copGFP-T2A-Puro (System

Biosciences). Lenti viral particles were generated at the University of Michigan Vector Core. LNCaP-AR cells were infected with lentivirus expressing ARLNC1 shRNA for 48 hours. Knockdown of ARLNC1 was confirmed by qPCR analysis. Male athymic nude mice were randomized into two groups at six to eight weeks of age. 5 million cells expressing sh- ARLNC1 or sh-vector were injected into bilateral flanks of mice. Caliper measurements were taken in two dimensions twice a week by an investigator blinded to the study objective and used to calculate tumor volume. The study was terminated when the tumor volume reached 1000 mm ³ . For ASO treatment in vivo, six to eight week old male athymic nude mice were inoculated subcutaneously with MDA-PCa-2b cells suspended in matrigel scaffold in the posterior dorsal flank region (5 million ceils/site, two sites/animal). When the mean tumor volume reached approximately 150 mm ³ , mice were randomized into two groups, respectively treated with ARLNC 1 -specific or control ASO ASOs, dosed 50 mg/kg, were subcutaneously injected between the scapulae once daily for three periods of five days on/two days off. Tumor size was measured twice per week using a digital caliper by a researcher blinded to the study design. Mouse body weights were monitored throughout the dosing period. When average tumor size in the control group reached 1500 mm ³ , mice were sacrificed and the primary tumors were excised for weight determination. One-third of the resected specimen was placed in 10% formalin buffer, and the remaining tissue was snap frozen.

BrU-seq and BrUChase-seq. BrU-seq and BrUChase-seq assays were performed as previously described ⁶³ _’ '”’ with MDA-PCa-2b cells treated with either siNT or sL4 Rlncl. BrU- labeiing w¾s performed for 30 minutes, and chase experiments were performed for 6h.

Statistical analysis. Statistical analysis was performed using Graphpad Prism 6 software. Data were presented as means ± s.e.m. All experimental assays were performed in triplicate unless otherwise specified. Statistical analyses shown in figures represent two-tailed /-tests, one-way ANOVA, two-w¾y ANOVA or Kruskal -Wallis rank sum test, as indicated. p<0.()5 were considered significant. Details regarding the statistical methods employed during microarray, RNA-Seq and ChIP-Seq data analysis were included in aforementioned methods for bioinformatic analyses.

Data availability. RNA-seq and Microarray data will be deposited into Gene Expression Omnibus upon manuscript acceptance.

Analysis of androgen receptor-regulated Iranscriptome in prostate cancer

To nominate AR-regulated genes (ARGs), RNA-Seq was performed on AR- dependent VCaP and LNCaP prostate cancer cell lines, stimulated with an AR ligand, dihydrotestosterone (DHT), for six and 24 hours (Figure 9a). 1702 genes were identified that were concordantly induced or repressed in VCaP and LNCaP at both time points (Figure la, Figure 9b~c), including over 500 IncRNAs (Figure la, Figure 9d); these data indicate that a large portion of the AR iranscriptome remains uncharacterized, specifically considering that the molecular heterogeneity of prostate cancer cannot be fully reflected by a small number of ceil lines.

To differentiate between direct and indirect ARGs, previously published AR chromatin immunoprecipitation (ChlP)-Seq data from LNCaP and VCaP cells were analyzed ³² . For direct AR targets, increased levels of AR binding at transcription start sites (TSS) in both LNCaP and VCaP cells was observed (Figure 9e). The binding levels were decreased following treatment with an AR antagonist (enzalutamide) (Figure 9f), and the binding sites revealed a de novo motif identical to the canonical AR response element ³³ (Figure 9h). A total of 987 genes were categorized as direct ARGs, including 341 IncRNAs (IncARG). Within these genes, an enrichment of chromatin marks associated with“open” chromatin (H3K27ac, H3K4mel ), active promoters (H3K4me3), and transcription

(H3K36me3) was observed, which together with Pol-11 occupancy are recognized as manifestations of active gene expression (Figure 9i). BET family proteins, such as BRIM, recognize acetylated histones and have been shown to promote AR transcriptional activity ³² . Consistently, the co-localization of BRD4 and AR at promoters of direct AR responsive genes and the loss of AR following treatment with a bromodomain inhibitor (JQ1) was observed (Figure 9f, i). It was determined whether ARGs identified from cell lines were also targeted by AR in normal prostate tissues and primary tumors. The dataset from Pomerantz el. al was queried for the presence of AR peaks within ARG promoters ³⁴ . Remarkably, tire majority of ARG promoters were TSS-proximally bound by AR in both tissues and cell lines (Figure 9j,k); conversely, AR-independent genes were distal to AR binding sites (Figure 91).

Finally, it was confirmed that the AR-regulated genes were also expressed in human prostate tissues. RNA-Seq data from normal prostate, clinically-localized PCa (The Cancer Genome Atlas, TCGA) ³⁵ , and me tastatic CRPC (Stand Up to Cancer- Prostate Cancer Foundation, SU2C-PCF) ³⁵ were interrogated (Figure lb). This revealed remarkable heterogeneity in the expression of ARGs during prostate cancer progression to metastatic disease. Compared to protein-coding genes, non-coding ARGs were detected at lower overall levels (Figure lc), although -10% of them showed robust expression of over 10 FPKM on average across prostate cancer samples.

ARLNC1 is a prostate lineage-specific !ncRNA with elevated expression in cancer

It was hypothesized that incRNAs associated with PCa progression and castration- resistance should either he up regulated if they enhance AR signaling or, conversely, downregulated if they attenuate AR signaling. Their expression is also expected to be AR- dependent and lineage-restricted if they are part of bona fide physiological feedback loops. Accordingly, a top-down strategy was developed in order to establish and prioritize dmically-relevamt, prostate cancer and lineage-specific incARGs. First, genes were identified that were both directly regulated by AR in VCaP/LNCaP cell lines and upregulated in primary (Figure 2a) or metastatic cancer (Figure 2b) compared to normal tissue. Canonical AR targets, including KLK3, KLK2, and TMPRSS2, were among the most differentially expressed protein coding genes. Importantly, this approach highlighted several novel IncARGs, including ARlncl (ENSG00000260896, PRCAT47 ¹⁰ ), and validated previously- identified IncARGs, such as CTBP1-AS ³⁶ (Figure 2a-b). ARlncl was found to be one of the most differentially expressed AR-regulated genes in both localized and metastatic PCa (Figure 2a~b, Figure lOa-b).

Next, the prostate lineage and cancer specificity of prostate cancer-associated IncRNAs was identified by leveraging the MiTranscriptome assembly ¹⁰ , an online resource to interrogate IncRNA expression across a multitude of tissue and tumor types, and Sample Set Enrichment Analysis (SSEA), which indicates the strength of cancer and lineage

association ¹⁰ . After applying an expression level filter (10 FPKM at the 95 ^th percentile), 12 of the most prostate lineage and prostate cancer-specific IncRNAs were identified (Figure 2c, Figure l Oc-d); five of these IncRNAs were regulated by AR. Across these analyses, ARlncl was the top prioritized transcript, warranting further investigation. Expression of ARlncl was interrogated across cancer and normal tissue RNA-Seq samples from TCGA and the Genotype-Tissue Expression (GTEX) project ³⁷ · ³⁸ , respectively in the TCGA cohort, ARlncl exhibited a highly prostate cancer-specific expression pattern, with little to no expression in other tumor types (Figure 2d). Similarly, in the GTEX normal tissue cohort, its expression was limited to the prostate (Figure lOe). Within prostate tissue, ARlncl expression, as assessed by RNA-Seq and in situ hybridization was significantly higher in localized and metastatic prostate cancers compared to benign ti ssues (Figure 2d inset, Figure 2e) In an extensive differential expression analysis using MiTranscriptome, ARlncl was found to be among the top 1% of genes most upregulated in prostate cancer and specific to the prostate lineage, with no significant associations in other tissues (Figure 1 Of) . Additionally, the protein-coding genes that were most correlated -with ARlncl were found to be associated with prostate cancer progression in multiple ONCOMINE clinical datasets ³⁹ (Figure lOg). Together, these results confirm Oast ARlncl expression is restricted to prostate cancer and associated with AR signaling throughout prostate cancer progression.

To functionally characterize ARlncl, appropriate prostate cancer cell lines with moderate to high levels of ARlncl expression were identified using in house RNA-Seq data (Figure 11a). Supporting the association of AR with ARlncl, ARlncl expression was highly enriched in AR-positive cell lines, with the highest expression in MDA-PCa-2b and LNCaP cells. In addition, qPCR analysis for the ARLNC1 transcript also demonstrated that this gene was expressed highest in MDA-PCa-2b and LNCaP cell lines (Fig. 1 lb). According to existing annotations, ARlncl is located on chromosome 16 and has several isoforms that differ in exon and TSS usage. Random amplification of cDNA ends (RACE) was performed in MDA-PCa-2b and LNCaP cells to determine the exact structure of ARlncl . A dominant TSS for ARlncl was found MDA-PCa-2b ceils, and tire 2.8 kb ARlncl isoform was further confirmed by northern blot analysis (Figure l ie). Single molecule fluorescent in situ hybridization (smFISH) revealed approximately 100 molecules of ARlncl transcripts existed per MDA-PCa-2b cell (Figure 1 Id-e). Using smFISH and qPCR, it was also found that ARLNC1 molecules were distributed equally between the nuclear and cytoplasmic cellular compartments (Fig. l !f-g).

ARLNC1 transcription is directly regulated by AR

Since ARlncl was identified as an AR-regulated IncRNA, AR ChIP-Seq data from DHT-stimulated VCaP and LNCaP cells w¾s interrogated for AR binding sites. An androgen- induced AR peak directly at the annotated promoter of ARlncl was identified in both VCaP and LNCaP cells (Figure 3a). This AR binding site was also observed in prostate tissue samples and contained a canonical AR binding motif (ARE) ³³ (Figure 3a). These observations were corroborated in MDA-PCa-2b cells, which showed the highest level of ARlncl expression, by ChIP-qPCR (Figure 3b). Considering the observation that ARlncl expression is prostate tissue-specific, while AR expression is not as much, other transcription factors and epigenetic modifiers that control ARlncl expression were identified (Figure 12a). Motif analysis of ARlncl promoter region identifies several transcription factor binding motifs, including a FOXA 1 -responsive motif. To further validate A RLNC1 gene regulation by AR and FOXA1, ARLNC1 transcript levels were evaluated following AR or FOXA1 knockdown. AR or FOXA1 loss resulted in decreased expression of ARLNCL along with other canonical AR target genes that served as positive controls (Fig. 3c, Fig. 12b). ChIP-seq and ChIP-PCR analysis additionally confirmed the putative FOXAl binding motif on the ARLNC1 promoter (Fig. 12c). Together, these observations indicate that ARLNCl is directly regulated by AR and modestly regulated by FOXAl , which, partially explains the tissue- specific expression pattern of ARLNC!, as expression of these two factors overlaps nearly exclusively in prostate tissue ³⁷ · ³⁸ (Fig. 12d).

To determine the function of ARlncl in prostate cancer, gene expression profiling of MDA-PCa-2b cells transfected with siRNAs targeting ARlncl was performed (Figure 4a). Enrichment analysis of the gene expression data revealed the deregulation of four main biological activities: apoptosis, cell proliferation, DNA damage response, and androgen signaling (Figure 4a). A significant decrease in AR target gene expression was particularly interesting given the fact that ARlncl is regulated by AR, indicating a positive feedback loop between ARlncl and AR signaling. To confirm this observation, an AR target gene signature was generated from MDA-PCa-2b cells stimulated with DHT (Figure 13a) and GSEA analysis was performed using tins gene signature (Figure 4b). Knockdown of ARlncl led to suppression of genes positively regulated by AR and upregulation of genes negatively regulated by AR in MDA-PCa-2b cells (Figure 4b-c, Figure 12b). This was further confirmed by AR reporter activity assay (Fig. 4d, Fig. 13c), as well as qPCR analysis of AR target genes (Fig. 13d). ARlncl knockdown also had a significant effect on the mRNA and protein levels of AR (Figure 4e-f), indicating direct regulation of AR by ARlncl. However, it was found that ARlncl overexpression did not have any effect on AR and its signaling cascade (Figure 13e). In situ co-localization of ARLNC1 and AR transcripts

Non-coding RNAs have been shown to target mRNAs via direct or indirect RNA- RNA interaction ⁹ · ⁴⁰ · ⁴² . To identify target mRNAs that could interact with ARlncl , an unbiased prediction of RNA-RNA interactions was performed using IntraRNA ⁴³ · ⁴⁴ . The 3’ UTR of the AR transcript was identified as a target of ARlncl (Figure 5a, Figure 14a). An in vitro RNA-RNA interaction assay between the 3’ UTR of AR and full-length ARlncl confirmed this in silica prediction (Figure 5b). To evaluate this interaction in the context of cellular environment, multiplexed smFISH for AR and ARLNC 1 transcripts was performed m MDA-PCa-2b cells. Upon co-staining MDA-PCa-2b cells with AR and a panel of

IncRNAs, or ARlnc l and a panel of mRNAs, specific colocalization was observed between AR and ARlncl transcripts in the nucleus within foci that were typically larger than individual molecules (Figure 5c-e). The extent of colocalization was much higher than that expected from co-incidental colocalization with an abundant transcript, such as MALAT1 or GAPDH (Figure 5c-e). More specifically, colocalization typically occurred at a stoichiometry' of 2: 1 ARlncl AR, accounting for -10-20% of all AR and ARlncl transcripts in the cell (Figure 14b). Furthermore, AR- ARlncl colocalization is observed in ARlncl -positive prostate cancer tissues.

Using in vitro RNA-RNA binding assay, nucleotides (nt) 700-1300 of ARlncl were identified as critical for binding to the AR 3’ UTR (Figure 6a-b). To confirm this observation within the cellular context, different fragments of ARlncl were ectopically overexpressed together with AR in U20S osteosarcoma cells, In this exogenous system, colocalization between AR and ARlncl was additionally demonstrated, wherein colocalization was dependent on the presence of 700-1300 nt of ARlncl (Figure 6c-d, Figure 14c). Furthermore, incubation with antisense oligos blocking the interaction site led to a significant reduction in ARlncl -AR interaction in vitro and in situ (Figure 6e-f Figure 14d~e). Decreased AR signaling was also observed following blocking of this interaction (Figure 6g, Figure 14f).

ARLNC1 regulates the cytoplasmic levels of AR transcripts

The mechanism of ARlncl -mediated AR regulation was investigated. The stability of these two transcripts was monitor and it was found that AR and ARlncl have similar half- lives of approximately 9 hours (Figure 14g). As ARlncl depletion resulted in a striking reduction of AR protein levels, much more than that explained by AR transcript reduction, it was hypothesized that ARlncl affects AR post-transcriptionally. To test this hypothesis, sub- cellular localization of AR transcripts was performed using smFISH after depleting ARlncl. Successful in situ knockdown of ARlncl was confirmed using siRNAs, antisense oligos (ASOs) and the blocking oligos targeting ARlncl -AR interaction (Blocking -ASOs) in MDA- PCa~2b cells (Figure 14h-i) Quantification of the sub-cellular distribution of ARlncl indicated that the nuclear fraction of ARlncl was enriched only in the -ARlncl condition (Figure 14j), as expected for siRNAs that are typically more functional m the cytosol ⁴⁵ . ARlncl knockdown or blocking AR-ARlncl interaction mediated a drastic reduction in cytoplasmic levels of AR transcript, but did not affect nuclear AR transcript levels, thereby resulting in an increased nuclear AR fraction (Figure 7a-b, Figure 14k -1). This observation was further supported by BrU-seq and BrU-chase-seq, high-throughput tools that monitors transcript synthesis and stability. Upon ARlncl knockdown, while synthesis rate of AR transcript remains the same (Figure 14m), while the stability of the transcript decreases, preferentially through the 3’UTR region (Figure 14h). Taken together, the data indicate that ARlnc l regulates the cytoplasmic levels of AR transcripts and that transcriptional coupling between AR and ARlncl transcripts is mediated by direct interactions which are encoded in their sequences.

Inhibition of ARLNC1 delays prostate cancer growth in vitro and in vivo

Having established a role for ARlncl in the regulation of AR signaling, the biological effects of ARlncl were further evaluated in prostate cancer cell lines. GO analysis of the knockdown microarray data showed that ARlncl -regulated genes were involved in cell proliferation and apoptosis (Figure 4a). Knockdown of ARlncl had a significant effect on the proliferation of AR-dependent MDA-PCa-2b and LNCaP cells, while no effect in AR- negative Du 145 and PCS cells (Figure 8a, Figure 15a-b). Knockdown of ARlncl also led to an increase in apoptosis in AR-positive prostate cancer cells (Figure 8b, Figure 15c). These results translated to effects in vivo, as cells expressing shRNA targeting ARlncl formed smaller tumors in mice compared to cells expressing non-targeting shRN A (Figure 8c), indicating that AR, mcl is an important survival factor for AR-dependent prostate cancer.

Since modulation of ^' ARlncl levels resulted in a striking proliferation phenotype, it was contemplated that ARlncl inhibition finds use therapeutically for the treatment of prostate cancer. Antisense oligos (ASOs) have recently been shown to be effective in targeting RNA in v/vo ^{46 49} , thus, ASOs targeting ARlnc l (Figure 15d) were generated .

Transfection of ASOs exhibited strong knockdown efficiency (Figure I5e), and ASO- mediated knockdown resulted in similar effects on gene expression profiling as siRNA (Figure 8d~e, Figure 15†) Furthermore, AR-positive cells transfected with ARlncl ASOs exhibited retarded growth, similar to siRNA (Figure 8f). To evaluate the therapeutic use of ARlncl ASOs in vivo , the cellular free uptake efficiency of ARlncl ASOs, a prerequisite for ASO therapeutic use, was evaluated. Several ASOs significantly reduced ARlncl levels through free uptake (Figure 15g). Free uptake of ARlncl ASOs led to a significant decrease in the proliferation capacity of MDA-PCa-2b cells in both normal cell culture and 3D sphere conditions (Figure 15h~j). Treatment of mice bearing MDA-PCa-2b xenografts with ARlncl - targeting ASO led to significant decreases in tumor growth compared to control ASO (Figure 8g-h, Figure 16a-e). Taken together, these data demonstrate that ARlncl plays a critical role m the proliferation of AR-dependent prostate cancer and can be effectively exploited as a therapeutic target, especially considering the association of this lncRNA with aggressive androgen signaling (Figure 16f-j).

As AR signaling remains a significant driver of CRPC pathogenesis, it is imperative to generate novel strategies for targeting of the pathway. Even with the addition of enzalutamide or abiraterone to CRPC treatment regimens, progression invariably occurs. Exploiting players other than AR itself that are pivotal to maintaining the magnitude of the androgen response is an alternative approach. This example describes a comprehensive profiling of AR-regulated, prostate cancer-associated IncRNAs and functionally characterized the top-ranking candidate, ARlncl . A positive feedback loop between ARlncl and AR that maintains the androgen transcriptional program in AR-positive prostate cancer cells, specifically through regulating the cellular levels of AR, was identified (Figure 8i). As a non-coding regulator of AR signaling, ARlncl provides a mechanistic biomarker and a therapeutic target for prostate cancer; acting upstream of AR signaling also presents the possibility that targeting of ARlncl may afford an additional option to patients that have de novo or acquired resistance to therapies targeting AR itself (e.g., enzalutamide or abiraterone). Furthennore, specific antisense nucleotides targeting ARlncl, which are shown to be only expressed in the prostate, can circumvent undesirable side effects that occur in other tissues with exposure to androgen synthesis inhibitors or antiandrogens.

Table 1

Table 2 (SEQ ID NO:73)

TTTTCAGTCTTTATTTTTCCCAAATTATCCTTCCCCTCTCTTAATTTGAATGAATAG

AAGGTTCTAGATTTATGGGTTTTTTTTTTTTTAATCTTTTTCTTTTTTGAGACAGAC

TCTCACTCTCGGGCTGGAGTGCAGCGGCATGATCTCGGCTCACTGCAACCTCTGC

CTCCCGGGTTCATGTAATTCTCATGCCTCAGCCTCCCAAGTAGCTGGGATTACAG

GCACACGCCACCATGCCTGGCTGATTTAAGATTATTTTTTTCACAAAACTTTGAA

GACATATCTTCTTATCTrCTGGCTTCTGTTGTTGTTCATTTACAGGTTTTCAGGTGC

TGGTTCCATGGCTCTTCCTGAGCCGAAAATAAGGAAACTCCATAGACCTTGTCCA

CTGGAACTCGTTCCCATCTACCCTCCACTCTATCCAGCCCCATGAGGACAAGGAA

CATGATTGGTTTTGCTCACTGCCGTATCTTCCGTACCTAGTACGTAACAGGACATC

AATAAATATTAGTTGAATGGAAGATTAAATCAACAAAATGGGTGATGGATCTCT

GCAGTAAGTGGAAGAGTTCTTCATGGCCCCCAAGGTTATATCCATCTAGAACTTC

AGCACGTAATTTCATCTGGAAATAGTGCCTTTGCGGATATAAGTTAGGTAAAACT

GAAGATGAGATCATACTGGATTAGGATGGGATCTAAATCCAATGAAAATGTCTT

CATAAAAAACAGGAAAGAACCCATAGAAACACAAGGAAGAAGGTCATGTGAAG

ATGGAGGCAGAGATTGGAGGGATGCAGCCACCGGCCCAGGAATGCCAGCAGCC

ACCCAGAAGCTGGAAGGAAATGAGGGATTCTCTCCTAGAACCTTTAGAGAGAAC

ATGGTCCTGTGAACAGCTTGATTTTGGACTTGCCCATAGCTTGTATACTCTTACTT

TGGATACAATTTTATCCAAACTTGGCTAAACAGTTTCTCAGCCTATGGAAAATTT

AAAATGGAGAAGATTCAACTCGATTCTTACAGATTCAAAGCAAGAAAATGATGG

GAACATAGGAGGAGACCAAGAAAGCCTA rAAAAAGCA AAATATGAAGTGAAC

ATTGTGGTAGCTTTAAGATGTTTAGTGTAGCTGCAGGCACCCTATACACATGAAA

ACCCCCAAGGGGAATCCCCATATCACAGTGTAGTGTGATATTTGACATTCGTGAT

CATCTAGAGATGTACAGAAAAGGTGAATCTGTGTTCTGTATATTCTGCCTAAGGC

AAAGAAATGTTTAGCTCTCTTTAAAATAGTTCCATAATTTTTTCTAAAAAGCTTTG

CTTGAAAACTGTAAGCTTCCCATATCTGGAGCATTTCACTTTAAATATTTGGATA

AATATGTTATCTTCTTACTTGGACATTTCATGTGTTTAGGGATTGTCTTCTAAATT

CTTCCTAATTCATATAGCTGCTAACACTTCCCGCAGAGCTAAACCATTACAGATA

CCTGGTACGGGGAGGAACAGAGTCCCTCCTTTACTTCTCCATTAGAAAGAATGAG

ATGGCAAGACAATGAAACAGGCAAAGTGAACAGAGATGCAAGACAAAATTCAG GTGAGAGAGCCAGAGCATCACTCAGCCATTCCTGACA FGI AAA AC AGGCAAC TA

GAAGTATTTGGAGACAATTCAGTGTTACATAAAATCTGCAAATCTCTGGATAAAG

AAGCAGAGATCCCAGCATGGGACAAATGGAGCCTCAAAAGTGGGAAGAAGACA

GAGAAGACCAGGGCAGAATGCATCTCTTCCTTTCTCTTGGCTTTCCTGGATAAGG

ACTGCATCATTCCTGTGGAAGGACAGGCCATCAGCTCCGAAACACTGTATGTATT

TTCCAGTATATACTGCTAGCTGTGTGATGTTGGGAAAATTTGTTACCCTGTCTAAC

CCCCACTTCCCTCATCTGTAAAATGGAAATAATGATAGTACCTACCTATCTCATA

GG FGGCAACT ACAAGGGGC AGCAC ACT C AGGGA A GG AAGGAAGT GT CAG fGAAC

ATCAACTTTATGAACACAGTGTTCATAAAGGCAGGTCAGTGCAGTGGTTTGGGAG

CCAGGAGAAGCACGTGGGCCGGAGTGTGCCTGCAGGAGACAAGGTCAGAGATGT

TGCTAATAATGGAGAATAAAGGATGCATTCTCATTACTGACCTTGGAGTCGTTCA

AGGTTTTGTTTATTATAGATACTAGGACTTAGTGGACCCAAGGTTAATGACATCC

AGAGTAGACAAACATCAAGTGTGTACTGCTTCTGTGCCAA

Table 3

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All publications and patents mentioned in the above specification are herein incorporated by reference. Various modifications and variations of the described method and system of the disclosure will be apparent to those skilled in the art without departing from the scope and spirit of the disclosure. Although the disclosure has been described in connection with specific preferred embodiments, it should be understood that the disclosure as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carr ing out the disclosure that are obvious to those skilled relevant fields are intended to be within the scope of the following claims.