Project description:We report the dual role of FoxA1 in androgen receptor recruitment to the chromatin of androgen responsive prostate cancer cell line LNCaP-1F5 using ChIP-sequencing. Depletion of FoxA1 reprograms both androgen and glucocorticoid receptor recruitment and subsequent gene expression. The ChIP-seq has been performed using AR, FoxA1, GR, H3K4me2 antibodies. We have also mapped the DNaseI-hypersensitive sites (DHS) using deep sequencing. Examination of AR, FoxA1, GR, H3K4me2 binding sites and DHS sites in parental and FoxA1 depleted LNCaP-1F5 cells.
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:We report the dual role of FoxA1 in androgen receptor recruitment to the chromatin of androgen responsive prostate cancer cell line LNCaP-1F5 using ChIP-sequencing. Depletion of FoxA1 reprograms both androgen and glucocorticoid receptor recruitment and subsequent gene expression. The ChIP-seq has been performed using AR, FoxA1, GR, H3K4me2 antibodies. We have also mapped the DNaseI-hypersensitive sites (DHS) using deep sequencing.
Project description:We report the dual role of FoxA1 in androgen receptor recruitment to the chromatin of androgen responsive prostate cancer cell line LNCaP-1F5 using ChIP-sequencing. Depletion of FoxA1 reprograms both androgen and glucocorticoid receptor recruitment and subsequent gene expression. The ChIP-seq has been performed using AR, FoxA1, GR, H3K4me2 antibodies. We have also mapped the DNaseI-hypersensitive sites (DHS) using deep sequencing.
Project description:We report the dual role of FoxA1 in androgen receptor recruitment to the chromatin of androgen responsive prostate cancer cell line LNCaP-1F5 using ChIP-sequencing. Depletion of FoxA1 reprograms both androgen and glucocorticoid receptor recruitment and subsequent gene expression. The ChIP-seq has been performed using AR, FoxA1, GR, H3K4me2 antibodies. We have also mapped the DNaseI-hypersensitive sites (DHS) using deep sequencing. LNCaP-1F5 cells were depleted of FoxA1 using siRNAs. Parental cells and FoxA1 depleted cells (siFoxA1) were treated with vehicle or 100 nM DHT or (100 nM DEX) for 24 hours followed by RNA isolation and hybridization to Illumina arrays. All the experiments have been performed in biological duplicates. Parental cells treated with DHT (or DEX) were analyzed for differentially expressed genes compared to vehicle treated parental cells. Similarly siFoxA1 cells treated with DHT (or DEX) were analyzed for differentially expressed genes compared to vehicle treated siFoxA1 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: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:Treatment of prostate cancer relies predominantly on the inhibition of androgen receptor (AR) signaling. Despite the initial effectiveness of the AR-targeted therapies, the cancer often develops resistance to the AR blockade. One mechanism of the resistance is glucocorticoid receptor (GR)-mediated replacement of AR. Nevertheless, the mechanistic ways and means how the GR-mediated antiandrogen resistance occurs has remained elusive. Here, we have discovered several crucial features of GR action in prostate cancer cells through genome-wide techniques. We detected that the replacement of AR by GR in antiandrogen-exposed prostate cancer cells occurs almost exclusively at pre-accessible chromatin sites displaying FOXA1 occupancy. Counterintuitively to the classical pioneer factor model, silencing of FOXA1 potentiated the chromatin binding and transcriptional activity of GR. This was attributed to FOXA1-mediated repression of the NR3C1 (gene encoding GR) expression via the corepressor TLE3. In comparison to FOXA1, inhibition of coregulator activity efficiently restricted GR-mediated gene regulation and cell proliferation. Overall, we identified chromatin pre-accessibility and FOXA1-mediated repression as important regulators of GR action in prostate cancer, pointing out new avenues to oppose steroid receptor-mediated drug resistance.