Project description:The androgen/androgen receptor (AR) signaling drives prostate development and prostatic carcinogenesis, whereas loss of the zinc finger homeobox 3 (ZFHX3) transcription factor attenuates prostate development and promotes prostatic tumorigenesis. The androgen/AR signaling upregulates the transcription of ZFHX3 in prostate cancer cells. However, whether and how ZFHX3 is involved in the function of AR signaling in prostate cancer cells is unknown. In this study, we first carried out RNA-seq analysis in C4-2B prostate cancer cells to detect what genes and signaling pathways are caused by the deletion of ZFHX3. Gene set enrichment analysis (GSEA) revealed that among the top altered hallmark gene sets after ZFHX3 deletion, only the one for androgen response was decreased, whereas those for TNFα, interferon γ, and inflammatory response were enriched. For the 27 genes indicative AR activities, as defined in a previous study, expression levels for 18 of the 27 genes were significantly changed by ZFHX3 loss. Fifteen of these 18 genes were downregulated, including classical AR target genes KLK3, FKBP5, and TMPRSS2.
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: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:Androgen receptor (AR) plays an important regulatory role during prostate cancer development. ARM-bM-^@M-^Ys transcriptional activity is regulated by androgenic ligands, but also by post-translational modifications. To study the role of the AR SUMOylation in genuine chromatin environment, we compared androgen-regulated gene expression and AR chromatin occupancy in PC-3 prostate cancer and HEK293 cell lines stably expressing wild-type (wt) or SUMOylation site-mutated AR (AR-K386R,K520R). Our genome-wide gene expression analyses reveal that the SUMOylation modulates the AR function in a target gene and pathway selective manner. The transcripts that are differentially regulated by androgen and SUMOylation are linked to cellular movement, cell death, cellular proliferation, cellular development and cell cycle. In line with these data, SUMOylation mutant AR cells proliferate faster and are more sensitive to apoptosis. Moreover, ChIP-seq analyses show that the SUMOylation modulates the chromatin occupancy of AR on many loci in a fashion that parallels with their differential androgen-regulated expression. De novo motif analyses show that other transcription factor-binding motifs are differentially enriched at the wtAR- and the AR-K386R,K520R-preferred genomic binding positions. Taken together, our data indicate that SUMOylation does not simply repress the AR activity, but it regulates ARM-bM-^@M-^Ys interaction with the chromatin and the receptorM-bM-^@M-^Ys target gene selection. Isogenic HEK293 cells stably expressing wild-type AR (wtAR) or SUMOylation-defective AR (AR-K2R) were treated 24 h with 10 nM R1881 or vehicle (EtOH). All conditions were performed in triplicate. The effect on gene expression was assessed by microarray.
Project description:We investigated the composition of chromatin protein network around endogenous androgen receptor (AR) in VCaP castration resistant prostate cancer cells using recently developed chromatin-directed proteomic approach called ChIP-SICAP . The androgen-induced AR chromatin protein network contained expected TFs, e.g. HOXB13, chromatin remodeling proteins, e.g. SMARCA4, and several novel candidates not previously associated with AR, e.g. prostate cancer biomarker SIM2. Based on these findings, the role of SMARCA4 and SIM2 was further characterized at AR chromatin domains . Silencing of SIM2 altered chromatin accessibility at a similar number of AR-binding sites as SMARCA4, an established ATPase subunit of the BAF chromatin remodeling complex, often aberrantly expressed in prostate cancer. Despite the wide co-occurrence on chromatin of SMARCA4 and AR, depletion of SMARCA4 influenced chromatin accessibility and expression of a restricted set of AR target genes, in particular those involved in cell morphogenetic changes in epithelial-mesenchymal transition. Silencing of SIM2, in turn, affected the expression of a much larger group of androgen-regulated genes, e.g. those involved in cellular responses to external stimuli and steroid hormone stimulus. The silencing also reduced proliferation of VCaP cells and tumor size in chick embryo chorioallantoic membrane assay, further suggesting the importance of SIM2 in the regulation 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 genes, CTBP2, FOXP1 and RUNX1. These factors interact with AR ligand dependently. In order to investigate androgen-regulated gene functions in prostate cancer cells, we performed gene expression in AR-positive prostate cancer cell lines after siRNA treatment. We also treated cells with vehicle or androgen to analyzed the effects of these genes on AR function. Observation of androgen dependent gene expression changes after treatment with siRNAs targeting FOXP1, CTBP2 and FOXA1 with microarray.
Project description:Androgen receptor (AR) plays an important regulatory role during prostate cancer development. ARM-bM-^@M-^Ys transcriptional activity is regulated by androgenic ligands, but also by post-translational modifications. To study the role of the AR SUMOylation in genuine chromatin environment, we compared androgen-regulated gene expression and AR chromatin occupancy in PC-3 prostate cancer and HEK293 cell lines stably expressing wild-type (wt) or SUMOylation site-mutated AR (AR-K386R,K520R). Our genome-wide gene expression analyses reveal that the SUMOylation modulates the AR function in a target gene and pathway selective manner. The transcripts that are differentially regulated by androgen and SUMOylation are linked to cellular movement, cell death, cellular proliferation, cellular development and cell cycle. In line with these data, SUMOylation mutant AR cells proliferate faster and are more sensitive to apoptosis. Moreover, ChIP-seq analyses show that the SUMOylation modulates the chromatin occupancy of AR on many loci in a fashion that parallels with their differential androgen-regulated expression. De novo motif analyses show that other transcription factor-binding motifs are differentially enriched at the wtAR- and the AR-K386R,K520R-preferred genomic binding positions. Taken together, our data indicate that SUMOylation does not simply repress the AR activity, but it regulates ARM-bM-^@M-^Ys interaction with the chromatin and the receptorM-bM-^@M-^Ys target gene selection. PC-3 cells stably expressing wild-type AR (wtAR) or SUMOylation-defective AR (AR-K2R) were treated 16 h with 10 nM R1881 or vehicle (EtOH). All conditions were performed in triplicate. The effect on gene expression was assessed by microarray.
Project description:Androgen receptor (AR) plays an important regulatory role during prostate cancer development. ARM-bM-^@M-^Ys transcriptional activity is regulated by androgenic ligands, but also by post-translational modifications. To study the role of the AR SUMOylation in genuine chromatin environment, we compared androgen-regulated gene expression and AR chromatin occupancy in PC-3 prostate cancer and HEK293 cell lines stably expressing wild-type (wt) or SUMOylation site-mutated AR (AR-K386R,K520R). Our genome-wide gene expression analyses reveal that the SUMOylation modulates the AR function in a target gene and pathway selective manner. The transcripts that are differentially regulated by androgen and SUMOylation are linked to cellular movement, cell death, cellular proliferation, cellular development and cell cycle. In line with these data, SUMOylation mutant AR cells proliferate faster and are more sensitive to apoptosis. Moreover, ChIP-seq analyses show that the SUMOylation modulates the chromatin occupancy of AR on many loci in a fashion that parallels with their differential androgen-regulated expression. De novo motif analyses show that other transcription factor-binding motifs are differentially enriched at the wtAR- and the AR-K386R,K520R-preferred genomic binding positions. Taken together, our data indicate that SUMOylation does not simply repress the AR activity, but it regulates ARM-bM-^@M-^Ys interaction with the chromatin and the receptorM-bM-^@M-^Ys target gene selection. Androgen receptor (AR) genomic binding was studied in wild-type AR (wtAR) or SUMOylation-deficient AR (AR-K2R) stably expressing cells HEK293 cells, in biological dublicates. Cells were treated 40 min either with 10 nM R1881 or EtOH (vehicle) and input was used as control (FRT_input GSM1176703).
Project description:Androgen receptor (AR) plays an important regulatory role during prostate cancer development. ARM-bM-^@M-^Ys transcriptional activity is regulated by androgenic ligands, but also by post-translational modifications. To study the role of the AR SUMOylation in genuine chromatin environment, we compared androgen-regulated gene expression and AR chromatin occupancy in PC-3 prostate cancer and HEK293 cell lines stably expressing wild-type (wt) or SUMOylation site-mutated AR (AR-K386R,K520R). Our genome-wide gene expression analyses reveal that the SUMOylation modulates the AR function in a target gene and pathway selective manner. The transcripts that are differentially regulated by androgen and SUMOylation are linked to cellular movement, cell death, cellular proliferation, cellular development and cell cycle. In line with these data, SUMOylation mutant AR cells proliferate faster and are more sensitive to apoptosis. Moreover, ChIP-seq analyses show that the SUMOylation modulates the chromatin occupancy of AR on many loci in a fashion that parallels with their differential androgen-regulated expression. De novo motif analyses show that other transcription factor-binding motifs are differentially enriched at the wtAR- and the AR-K386R,K520R-preferred genomic binding positions. Taken together, our data indicate that SUMOylation does not simply repress the AR activity, but it regulates ARM-bM-^@M-^Ys interaction with the chromatin and the receptorM-bM-^@M-^Ys target gene selection. Androgen receptor (AR) genomic binding was studied in wild-type AR (wtAR) or SUMOylation-deficient AR (AR-K2R) stably expressing cells PC-3 cells, in biological dublicates. Cells were treated 1h either with 10 nM R1881 or vehicle and inputs were used as controls.
Project description:BPTF, the scaffolding subunit of the nucleosome remodeling factor (NURF) complex, has been implicated in the progression of several malignancies, but its role in prostate cancer (PCa) remains unclear. Here, we demonstrate that BPTF is upregulated in castration-resistant prostate cancer (CRPC) and promotes disease progression. RNA-seq revealed that BPTF primarily enhances the expression of androgen receptor (AR) target genes. ChIP-seq showed that BPTF increases AR binding at promoters, enhancers and super-enhancers. ATAC-seq further demonstrated that BPTF increases chromatin accessibility to facilitate AR binding, in part through SMARCA1, a catalytic subunit of the NURF complex. Notably, BPTF/AR co-bound regions are highly enriched for FOXA1 motifs but only weakly enriched for AR motifs. We further show that BPTF forms a protein complex with AR and FOXA1, in which FOXA1 recruits the BPTF-AR complex to chromatin, while BPTF stabilizes the AR-FOXA1 interaction. Importantly, BPTF interacts with AR through its bromodomain, and a BPTF bromodomain inhibitor disrupts this interaction, impairs AR signaling and suppresses PCa cell growth. In summary, our findings establish BPTF as a critical regulator of AR activity by promoting chromatin accessibility and stabilizing the AR-FOXA1 complex, highlighting BPTF as a potential therapeutic target in prostate cancer.