Project description:Genome-wide association studies have identified 270 loci conferring risk for prostate cancer (PCa), yet the underlying biology and clinical impact remain to be investigated. Here we observe an enrichment of transcription factor genes including HNF1B within PCa risk-associated regions. While focused on the 17q12/HNF1B locus, we find a strong eQTL for HNF1B and multiple potential causal variants involved in the regulation of HNF1B expression in PCa. An unbiased genome-wide co-expression analysis reveals PCa-specific somatic TMPRSS2-ERG fusion as a transcriptional mediator of this locus and the HNF1B eQTL signal is ERG fusion status dependent. We investigate the role of HNF1B and find its involvement in several pathways related to cell cycle progression and PCa severity. Furthermore, HNF1B interacts with TMPRSS2-ERG to co-occupy large proportion of genomic regions with a remarkable enrichment of additional PCa risk alleles. We finally show that HNF1B co-opts ERG fusion to mediate mechanistic and biological effects of the PCa risk-associated locus 17p13.3/VPS53/FAM57A/GEMIN4. Taken together, we report an extensive germline-somatic interaction between TMPRSS2-ERG fusion and genetic variations underpinning PCa risk association and progression.
Project description:Here, we developed immunoprecipitation-mass spectrometry assays for the measurement of a low-abundance T1E4 TMPRSS2-ERG fusion protein, its isoforms and its interactome in VCaP prostate cancer cells.
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. ChIP_Seq examination of histone modifications and key transcription factors in LNCaP and VCaP prostate cancer cell lines in un-treated, vehicle treated or 10nM R1881 treated conditions. LNCaP ChIP-Seq experiments include samples GSM353609-GSM353618, GSM353625-GSM353628, GSM353633-GSM353635, GSM353641-GSM353644, and GSM353648. VCaP ChIP-Seq experiments include samples GSM353601-GSM353608, GSM353619-GSM353624, GSM353629-GSM353632, and GSM353645-GSM353647. In addition, we performed re-ChIP of AR and ERG in VCaP cells (GSM356767), and examined the effect of ERG knockdown on AR and ERG binding (samples GSM353636-GSM353639). To study ectopic ERG binding we performed ERG ChIP-Seq in stable RWPE+ERG or control cells (samples GSM353649-GSM353650). AR ChIP-Seq was also done in the AR-positive but ETS fusion-negative 22RV1 cells (GSM353640). To further study transcription factor binding and chromatin state we performed ChIP-Seq of AR, ERG, H3K4me3, H3K9me3, H3K27me3 and RNA Pol II in a metastatic prostate tumor tissue (samples GSM353651-GSM353656). To couple the ChIP-Seq experiments with gene expression, we have also done Illumian SAGE-tag profiling in LNCaP cells following androgen treatment for 0, 24 and 48hrs. These DGE experiments correspond to samples GSM353657-GSM353659.
Project description:The TMPRSS2-ERG fusion positive prostate cancer cell line VCaP was grown for 72h in steroid depleted media (RPMI 10% CDT FBS) prior to vehicle (ethanol) or androgen stimulation (1nM R1881). To allow detailed analysis of androgen regulated gene expression in the VCaP prostate cancer cell line total RNA was harvested every every hour up to 24h using trizol (Sigma), quantified using a Nanodrop spectrophotometer (ND-1000). RNA samples were prepared for analysis on Illumina Human 12 v3 BeadArrays. Raw bead-summary data were generated using GenomeStudio version 1.9.0 (Illumina Inc.). For integrative analysis expression array data were normalised in R using the beadarray software and BASH (see Supplementary Methods for details) (Cairns et al., 2008; Dunning et al., 2007).
Project description:The goal of this project was to analyze the global gene expression profiles of RWPE1 and VCAP cells following transfection of GFP, GFP-ERG at 48 and 72hrs time points and stable ERG shRNA, scramble shRNA, respectively. RWPE1 cells were transfected with GFP or GFP-ERG. VCAP cells were transfected with ERG lenti-shRNA or scramble shRNA. Transfections were performed in duplicate. Total cellular RNA was isolated with Trizol and quality analysed by the bioanalyser kit.
Project description:The goal of this project was to analyze the global gene expression profiles of RWPE1 and VCAP cells following transfection of GFP, GFP-ERG at 48 and 72hrs time points and stable ERG shRNA, scramble shRNA, respectively.
Project description:Chromosomal rearrangements involving ETS factors, ERG and ETV1, occur frequently in prostate cancer. We here examine human prostate cancer cells control VCaP and LNCaP cells with ERG- or ETV1-silenced VCaP or LNCaP cells, respectively, in hormone deprived and stimulated conditions.
Project description:Microarray studies was performed to analyze gene expression profiling in VCaP cells after ERG was silenced by two different siRNAs or VCaP cells were treated by WP1130.
Project description:Deregulation of the Androgen Receptor (AR) transcriptional network is a common hallmark in prostate cancers. To achieve its precise transcriptional role, AR needs to co-operate specifically with a plethora of cofactors. In prostate cancers, AR transcription collaborators are frequently aberrantly over-expressed, altering the AR signaling pathway to one that promotes oncogenesis. Recently, the prostate cancer recurrent fusion gene, ERG, was shown to promote tumor progression by acting as a repressor of AR signaling. However, the exact mechanics and the functional consequences associated with this crosstalk between ERG and AR still remains relatively unknown. Interestingly, through chromatin immunoprecipitation coupled with massively parallel sequencing, we discover that ERG and other commonly over-expressed transcriptional co-repressors (HDAC1, HDAC2, HDAC3 and EZH2) are wired into an AR centric transcriptional network via a spectrum of distal enhancers and/or proximal promoters. We show that ERG represses several AR target genes involved in epithelial differentiation. Furthermore, we demonstrated that suppression of the androgen induced gene, Vinculin, by ERG and histone deacetylases increases cancer cell invasiveness. From our results, we propose that ERG, histone deactelyases and the histone methyltransferase, EZH2, could impede epithelial differentiation and contribute to prostate cancer progression, in part through modulating the transcriptional output of AR. Gene expression profiling of human prostate cancer VCaP cells with time course DHT stimulation using microarray.