Project description:The spliced variant forms of androgen receptor (AR-Vs) have been identified recently in castration-resistant prostate cancer (CRPC) cell lines and clinical samples. Here we identified the cistrome and transcriptome landscape of AR-Vs in CRPC cell lines and determine the clinical significance of AR variants regulated gene.The AR variants binding sites can be identified in 22Rv1 cell line in the absence of androgen. Knocking down full-length AR (AR-FL) doesn't affect AR-Vs binding sites in genome-wide. A set of genes were identified to be regulated uniquely by AR-Vs, but not by AR-FL in androgen-depleted condition. Integrated analysis showed that some genes may be modulated by AR-Vs directly. Unsupervised clustering analysis demonstrated that AR variants gene signature can separate not only the benign and malignant prostate tissue, but also the localized prostate cancer and metastatic CRPC specimens. Some genes modulated uniquely by AR variants were also identified to correlate with the Gleason Pattern of prostate cancer and PSA failure. We conclude that AR spliced variants bind to DNA independent of full-length AR, and can modulate a unique set of genes which is not regulated by full-length AR in the absence of androgen. AR variants gene signature correlate with CRPC and prostate cnacer disease progress. Androgen receptor (AR) binding sites in human prostate cancer 22Rv1 cell lines were studied using ChIP-seq. ChIP enriched and input DNA were sequenced using Illumina HiSeq 2000.
Project description:In castration-resistant prostate cancer (CRPC), clinical response to androgen receptor (AR) antagonists is limited mainly due to AR-variants expression and restored AR signaling. The metabolite spermine is most abundant in prostate and it decreases as prostate cancer progresses, but its functions remain poorly understood. Here, we show spermine inhibits full-length androgen receptor (AR-FL) and androgen receptor splice variant 7 (AR-V7) signaling and suppresses CRPC cell proliferation by directly binding and inhibiting protein arginine methyltransferase PRMT1. Spermine reduces H4R3me2a modification at the AR locus and suppresses AR binding as well as H3K27ac modification levels at AR target genes. Spermine supplementation restrains CRPC growth in vivo. PRMT1 inhibition also suppresses AR-FL and AR-V7 signaling and reduces CRPC growth. Collectively, we demonstrate spermine as an anticancer metabolite by inhibiting PRMT1 to transcriptionally inhibit AR-FL and AR-V7 signaling in CRPC, and we indicate spermine and PRMT1 inhibition as powerful strategies overcoming limitations of current AR-based therapies in CRPC.
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.
Project description:We report the high-throughput profiling of histone modifications in prostate cancer cells. By obtaining over 1 billion bases of sequence from chromatin immunoprecipitated DNA, we generated genome-wide chromatin-state maps of prostate cancer cells. we found androgen treatment dismisses a nucleosome over AR binding sites that are flanked by a pair of H3K4me2 marked nucleosomes. A novel quantitative model built on the behavior of such nucleosome pairs correctly identified regions bound by the regulators of the immediate androgen response including AR and FoxA1. More importantly this model also correctly predicted novel binding sites for other transcription factors present following prolonged androgen stimulation including Oct1 and NKX3.1. Thus quantitative modeling of enhancer structure provides a powerful predictive method to infer the identity of transcription factors involved in cellular responses to specific stimuli. Examination of 2 different histone modifications in prostate cancer cells with and without androgen (dihydrotestosterone, DHT) treatment.
Project description:Androgen receptor (AR) and hypoxia inducible factor 1a (HIF1a) are transcription factors that promote prostate cancer progression. This study investigated the relationship between the AR and HIF1a signaling pathways. ChIP-seq analysis was performed on the LNCaP cell line to identify global HIF and AR binding sites within the genome, under hypoxia and normoxia and in the presence and absence of androgen treatment.
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. Gene expression profiling of LNCaP in response to ETOH (vehicle) or DHT (5α-dihydrotestosterone) stimulation across different treatment time-points using microarray.
Project description:We profiled androgen receptor (AR) genomic targets using high-throughput sequencing of chromatin-immunoprecipitated (ChIP) DNA from TMPRSS2-ERG fusion gene positive DUCaP prostate cancer cells. ChIp-seq and microarray gene expression profiling datasets were integrated with the NHGRI GWAS PCa risk SNPs catalog to identify disease susceptibility SNPs localized within functional androgen receptor binding sites (ARBSs). Eighty GWAS index or linked SNPs were found to be localized in ARBSs. Among these rs11891426:T>G in the 7th intron of the melanophilin gene was found located within a novel putative auxiliary AR binding motif, which we found enriched in the neighborhood of canonical androgen responsive elements. T→G exchange attenuated the transcriptional activity of the ARBS in an AR reporter gene assay of prostate cancer cell models. It went also in line with decreased melanophilin protein level in primary prostate tumors with G allele.These results unravel a hidden link between androgen receptor and a functional PCa risk SNP, whose allele alteration affects androgen regulation of its host gene melanophilin . Genomic profile of androgen receptor binding sites of androgen or vehicle treated DUCaP cells using ChIP-seq. IgG precipiated DNAs from both treatments served as controls.