Project description:The androgen receptor (AR) directs diverse biological processes through interaction with coregulators such as androgen receptor trapped clone-27 (ART-27). The impact of ART-27 on genome-wide transcription was examined. The studies indicate that loss of ART-27 enhances expression of many androgen-regulated genes, suggesting that ART-27 inhibits gene expression. Surprisingly, classes of genes that are upregulated upon ART-27 depletion include regulators of DNA damage checkpoint and cell cycle progression, suggesting that ART-27 functions to keep expression levels of these genes low. Keywords: LNCaP, cell type comparison, UXT, ART-27, androgen receptor, R1881, AR, androgen-regulated gene expression, prostate cancer
Project description:The androgen receptor (AR) directs diverse biological processes through interaction with coregulators such as androgen receptor trapped clone-27 (ART-27). The impact of ART-27 on genome-wide transcription was examined. The studies indicate that loss of ART-27 enhances expression of many androgen-regulated genes, suggesting that ART-27 inhibits gene expression. Surprisingly, classes of genes that are upregulated upon ART-27 depletion include regulators of DNA damage checkpoint and cell cycle progression, suggesting that ART-27 functions to keep expression levels of these genes low. Experiment Overall Design: Steroid-deprived LNCaP cells were transfected with control or ART-27 siRNA and stimulated with ethanol vehicle or 10 nM R1881 for 18 hrs. 8 samples, 4 conditions, 2 replicates per condition.
Project description:Androgen receptor (AR) signaling is a major driver and therapy target in prostate cancer. Several inhibitors of AR function are approved for different stages of the disease and their impact on downstream gene transcription has been described. However, the ensuing effects of androgen and anti-androgens at the protein level are less well understood. Here, we focused on the AR inhibitor darolutamide which has recently been approved for non-metastatic castration-resistant prostate cancer. Here we determined the impact of darolutamide, a recently approved AR antagonist which significantly extends progression-free and overall survival in non-metastatic CRPC (31, 32), on the prostate cancer proteome. We first determined the direct binding between darolutamide and the AR in living prostate cancer cells in a label-free context using the cellular high throughput thermal shift assay (CETSA HT). We then generated comprehensive proteomic profiles of prostate cancer cells treated with androgen and darolutamide, and compared them with transcriptomic profiles. We found a generally high concordance between proteomic and transcriptomic data, both on the level of detected expressed genes and their protein products, as well as in terms of the corresponding biological programs. However there were cases where protein and gene expression levels were not regulated in parallel, suggesting an additional post-transcriptional regulation step controlling protein abundance to occur in several instances.
Project description:Androgen receptor (AR) is a transcription factor that plays a central role in the growth and development of the normal prostate and its malignant transformation. More recently, a majority of prostate cancers have been shown to harbor recurrent gene fusions of the androgen-regulated gene, TMPRSS2, to the oncogenic ETS transcription factor ERG. Here we employed chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-Seq) to explore the genome-wide localization of these transcription factors in human prostate cancer cell lines as well as tissues. Unexpectedly, transcriptional networks emanating from AR and ERG were found to be highly overlapping. Furthermore, AR was found to regulate known 5’ fusion partners in prostate cancer including TMPRSS2, as well as negatively regulating its own expression. While induced by androgen through fusion to TMPRSS2, ERG itself was shown to inhibit AR expression and positively regulate the genomic locus of wild-type ERG, thus revealing multiple levels of molecular cross-talk between AR and ERG. Importantly, androgen-sensitive prostate cancer cells in which ERG is overexpressed are able to proliferate and invade in the absence of androgen. Thus, we dissected the intertwined genomic landscape of two master transcriptional regulators of prostate cancer and suggest a role for ERG in maintaining transcriptional networks necessary for androgen-independent prostate cancer growth. These studies may suggest that future therapies against prostate cancer should target both AR and ERG, rather than AR alone, in order to achieve maximum effectiveness. Keywords: Genetic modification
Project description:Androgen receptor (AR) is a transcription factor that plays a central role in the growth and development of the normal prostate and its malignant transformation. More recently, a majority of prostate cancers have been shown to harbor recurrent gene fusions of the androgen-regulated gene, TMPRSS2, to the oncogenic ETS transcription factor ERG. Here we employed chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-Seq) to explore the genome-wide localization of these transcription factors in human prostate cancer cell lines as well as tissues. Unexpectedly, transcriptional networks emanating from AR and ERG were found to be highly overlapping. Furthermore, AR was found to regulate known 5’ fusion partners in prostate cancer including TMPRSS2, as well as negatively regulating its own expression. While induced by androgen through fusion to TMPRSS2, ERG itself was shown to inhibit AR expression and positively regulate the genomic locus of wild-type ERG, thus revealing multiple levels of molecular cross-talk between AR and ERG. Importantly, androgen-sensitive prostate cancer cells in which ERG is overexpressed are able to proliferate and invade in the absence of androgen. Thus, we dissected the intertwined genomic landscape of two master transcriptional regulators of prostate cancer and suggest a role for ERG in maintaining transcriptional networks necessary for androgen-independent prostate cancer growth. These studies may suggest that future therapies against prostate cancer should target both AR and ERG, rather than AR alone, in order to achieve maximum effectiveness.
Project description:The transcription factor and RNA-interacting Y-box binding protein-1 (YB-1 protein, YBX1 gene) has gained interest as a prognostic biomarker and therapeutic target in various malignancies including prostate cancer. Using a custom prostate-cancer-focussed microarray platform, we have established a transcriptome-wide profile of YB-1 target transcripts in the androgen sensitive prostate cancer cell line LNCaP, including RNAs regulated by YB-1 at the transcriptional and post-transcriptional level; under standard culture conditions (FBS), in androgen deprived culture conditions (CSS) and following stimulation with dihydrotestosterone (DHT). This SuperSeries is composed of the SubSeries listed below.
Project description:The majority of the human genome is transcribed, yielding a rich repository of non-coding transcripts that are involved in a myriad of biological processes including cancer. However, how non-coding transcripts such as Long Non-coding RNAs (lncRNAs) function in prostate cancer is still unclear. In this study, we have identified a novel set of clinically relevant androgen-regulated lncRNAs in prostate cancer. Among this group, we found LINC00844 is a direct androgen regulated target that is actively transcribed in AR-dependent prostate cancer cells. In clinical analysis, the expression of LINC00844 is higher in normal prostate compared to malignant and metastatic prostate cancer samples and patients with low expression demonstrate poor prognosis and significantly increased biochemical recurrence suggesting LINC00844 may function in suppressing tumor progression and metastasis. From in-vitro loss-of-function studies, we showed LINC00844 prevents prostate cancer cell migration and invasion. Moreover, in gene expression studies we demonstrate LINC00844 functions in trans, affecting global androgen-regulated gene transcription. Mechanistically, we provide evidence to show LINC00844 is important in facilitating AR binding to the chromatin. Finally, we showed LINC00844 mediates its phenotypic effects in part by activating the expression of NDRG1, a crucial cancer metastasis suppressor. Collectively, our findings indicate LINC00844 is a novel coregulator of AR that plays an important role in the androgen transcriptional network and the development and progression of prostate cancer.
Project description:The majority of the human genome is transcribed, yielding a rich repository of non-coding transcripts that are involved in a myriad of biological processes including cancer. However, how non-coding transcripts such as Long Non-coding RNAs (lncRNAs) function in prostate cancer is still unclear. In this study, we have identified a novel set of clinically relevant androgen-regulated lncRNAs in prostate cancer. Among this group, we found LINC00844 is a direct androgen regulated target that is actively transcribed in AR-dependent prostate cancer cells. In clinical analysis, the expression of LINC00844 is higher in normal prostate compared to malignant and metastatic prostate cancer samples and patients with low expression demonstrate poor prognosis and significantly increased biochemical recurrence suggesting LINC00844 may function in suppressing tumor progression and metastasis. From in-vitro loss-of-function studies, we showed LINC00844 prevents prostate cancer cell migration and invasion. Moreover, in gene expression studies we demonstrate LINC00844 functions in trans, affecting global androgen-regulated gene transcription. Mechanistically, we provide evidence to show LINC00844 is important in facilitating AR binding to the chromatin. Finally, we showed LINC00844 mediates its phenotypic effects in part by activating the expression of NDRG1, a crucial cancer metastasis suppressor. Collectively, our findings indicate LINC00844 is a novel coregulator of AR that plays an important role in the androgen transcriptional network and the development and progression of prostate cancer.
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: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.