Project description:Widespread alternative polyadenylation regulation reprograms the prostate cancer cell transcriptome upon androgen receptor inhibition
Project description:Although the vital role of the androgen receptor (AR) has been well demonstrated in primary prostate cancers, its role in the androgen-insensitive prostate cancers still remains unclear. Here, we used a small hairpin RNA approach to directly assess AR activity in prostate cancer cells. Reduction of AR expression in the two androgen-sensitive prostate cancer cell lines, LNCaP and LAPC4, significantly decreased AR-mediated transcription and cell growth. Intriguingly, in two androgen-insensitive prostate cell lines, LNCaP-C42B4 and CWR22Rv1, knockdown of AR expression showed a more pronounced effect on AR-induced transcription and cell growth than androgen depletion. Using cDNA microarrays, we also compared the transcriptional profiles induced by either androgen depletion or AR knockdown. Although a significant number of transcripts appear to be regulated by both androgen depletion and AR knockdown, we observed a subset of transcripts affected only by androgen depletion but not by AR knockdown, and vice versa. Finally, we demonstrated a direct role for AR in promoting tumor formation and growth in a xenograft model. Taken together, our results elucidate an important role for the AR in androgen-insensitive prostate cancer cells, and suggest that AR can be used as a therapeutic target for androgen-insensitive prostate cancers.
Project description:Although the vital role of the androgen receptor (AR) has been well demonstrated in primary prostate cancers, its role in the androgen-insensitive prostate cancers still remains unclear. Here, we used a small hairpin RNA approach to directly assess AR activity in prostate cancer cells. Reduction of AR expression in the two androgen-sensitive prostate cancer cell lines, LNCaP and LAPC4, significantly decreased AR-mediated transcription and cell growth. Intriguingly, in two androgen-insensitive prostate cell lines, LNCaP-C42B4 and CWR22Rv1, knockdown of AR expression showed a more pronounced effect on AR-induced transcription and cell growth than androgen depletion. Using cDNA microarrays, we also compared the transcriptional profiles induced by either androgen depletion or AR knockdown. Although a significant number of transcripts appear to be regulated by both androgen depletion and AR knockdown, we observed a subset of transcripts affected only by androgen depletion but not by AR knockdown, and vice versa. Finally, we demonstrated a direct role for AR in promoting tumor formation and growth in a xenograft model. Taken together, our results elucidate an important role for the AR in androgen-insensitive prostate cancer cells, and suggest that AR can be used as a therapeutic target for androgen-insensitive prostate cancers. Set of arrays organized by shared biological context, such as organism, tumors types, processes, etc. Keywords: Logical Set Computed
Project description:Prostate cancer (PC) onset and progression relies on the androgen receptor (AR) signaling. Anti-androgenic hormonal therapy (HT) is initially efficacious, but most patients evolve to a castration resistant stage (CRPC) for which no cure is currently available. Most proposed mechanisms of acquired resistance to HT focus on the transcriptional activity in CRPC cells. In this study, however, we have uncovered a new role of AR in alternative cleavage and polyadenylation (APA) regulation.
Project description:This SuperSeries is composed of the following subset Series: GSE30622: Dual Role of FoxA1 in Androgen Receptor Binding to Chromatin, Androgen Signaling and Prostate Cancer [Expression Array] GSE30623: Dual Role of FoxA1 in Androgen Receptor Binding to Chromatin, Androgen Signaling and Prostate Cancer [ChIP_seq, DHS_seq] Refer to individual Series
Project description:Prostate cancer is the most common cancer in men and androgen receptor (AR) downstream signalings promote prostate cancer cell proliferation. To investigate the AR signaling, we performed directional RNA sequence analysis in AR positive prostate cancer cell line, LNCaP and VCaP. Using Noncode and GENCODE data sets. We identified androgen-regulated long non-coding RNAs (lncRNAs) in prostate cancer cells. Directional RNA sequence analysis of androgen-regulated lncRNAs in prostate cancer cells
Project description:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. We identified androgen-regulated long non-coding RNA, CTBP1-AS, located in the antisese region of CTBP1 gene. CTBP1-AS activate AR signaling by epigenetically repress AR-associated cofactors such as CTBP1 by interactign with RNA-binding protein PSF and recruiting HDAC complex to the target promoters. In order investigated the PSF target genes, we performed ChIP-seq analysis of PSF binding sites in prostate cancer cell line, LNCaP cells. We identified androgen dependent PSF binding regions in prostate cancer cell genome. We observed PSF bindings around the promoters of androgen repressed genes such as CTBP1, p53 and SMAD3. ChIP-sequence analysis of PSF binding sites in prostate cancer cells
Project description:Androgen receptor (AR) orchestrates an intricate transcriptional regulatory network that governs prostate cancer initiation, development and progression. To understand this network in detail, we generated genome-wide maps of AR occupancy by ChIP-seq in LNCaP cells. We found NKX3-1, an androgen-dependent homeobox protein well-characterized for its role in prostate development and differentiation, being recruited to AR binding sites (ARBS) in response to androgen signaling. We identified 6,359 NKX3-1 binding sites, most of which overlapped with AR. In addition to its novel collaborative transcriptional role at well-known prostate cancer model genes, our binding and knockdown studies further suggested that NKX3-1 potentially regulates AR in a feed-forward manner. Integrative analysis of Oncomine molecular concepts showed that these androgen-regulated AR and NKX3-1 associated genes are significantly overexpressed in prostate carcinoma as well as advanced and recurrent prostate tumors. From our transcriptomic profiling and Gene Ontology analysis, we observed that AR and NKX3-1 co-regulate genes involved in "protein trafficking" processes, which are mandatory events in the integration of oncogenic signaling pathways leading to prostate cancer development and progression. Interestingly, we found that AR and NKX3-1 co-regulate several members of the RAB GTPase family of secretory/trafficking proteins via the involvement of FoxA1 in a ternary complex and we believe that these AR/NKX3-1/FoxA1 co-regulated RAB genes could serve as expression signatures in prostate carcinogenesis. More specifically, through functional analyses, we showed that NKX3-1, together with AR and FoxA1, could promote prostate cancer cell survival through activation of RAB3B expression. Collectively, our study has provided important insights into the hierarchical transcriptional regulatory network established between AR and NKX3-1 and sought to elucidate the important genetic-molecular-phenotypic paradigm in androgen-dependent prostate cancer. Genome-wide binding analyses of AR, NKX3-1 and FoxA1 in LNCaP with or without DHT (5alpha-dihydrotestosterone) stimulation using ChIP-Seq.