Hormone-Independence of Prostate Cancer Cells is Supported by the Androgen Receptor without Binding to Classical Response Elements
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ABSTRACT: Treatment of late passage (LP50) LNCaP cells with R1881 (androgen) and AR shRNA identified a gene program controlled by androgen receptor in the absence of androgen. Gene expression in late passage (LP50) LNCaP cells that had enhanced androgen-independent growth was determined in androgen-depleted medium in response to R1881 or AR knock down via AR shRNA
Project description:Treatment of late passage (LP50) LNCaP cells with R1881 (androgen) and AR shRNA identified a gene program controlled by androgen receptor in the absence of androgen.
Project description:Elk1 directs selective gene induction that is a substantial and critical component of growth signaling by AR in PC cells. Gene expression in LNCaP cells was determined in androgen-depleted medium in response to R1881 in ELK1 knock down (via AR shRNA) or in cells treated with control shRNA.
Project description:Androgen receptor (AR) is a key player in prostate cancer development and progression. Here we applied immunoprecipitation mass spectrometry of endogenous AR in LNCaP cells to identify components of the AR transcriptional complex. In total, 66 known and novel AR interactors were identified in the presence of synthetic androgen, most of which were critical for AR-driven prostate cancer cell proliferation. A subset of AR interactors required for LNCaP proliferation were profiled using chromatin immunoprecipitation assays followed by sequencing, identifying distinct genomic subcomplexes of AR interaction partners. Interestingly, three major subgroups of genomic subcomplexes were identified, where selective gain of function for AR genomic action in tumorigenesis was found, dictated by FOXA1 and HOXB13. In summary, by combining proteomic and genomic approaches we reveal subclasses of AR transcriptional complexes, differentiating normal AR behavior from the oncogenic state. In this process, the expression of AR interactors has key roles by reprogramming the AR cistrome and interactome in a genomic location-specific manner.
Project description:Transcriptional profiling of LNCaP prostasphere-forming cells, comparing control untreated sphere-forming cells with hormone treated sphere-forming cells. Both estrogen (estradiol) and androgen (R1881) promote the sphere formation of human prostate cancer cell LNCaP. Goal was to determine the effects of hormones on global gene expression of LNCaP sphere-forming cells. Five samples were analyzed. Control (ethanol 1hr), estradiol 1 hour, estradiol 24 hour, R1881 1 hour, R1881 24 hour.
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:Using DNase-seq, mRNA-seq and publicly available ChIP-seq data sets, we examined the role of chromatin accessibility (DNase-seq) in androgen receptor binding to the genome (ChIP-seq) and AR-mediated transcriptional changes (mRNA-seq). Our data reveals genome-wide changes in chromatin structure that correspond to AR binding and differential gene expression. A focused examination of DNase-seq data around androgen receptor motifs within androgen receptor ChIP-seq peaks reveals distinct patterns of protection from DNaseI cleavage. Examination of chromatin accessibility (DNase-seq), AR binding (AR ChIP-seq), and transcription (mRNA-seq) in LNCaP cells before and after 12 hours of 1 nM R1881 treatment This Series represents the RNA-Seq data only. Exon microarray data generated under the same conditions is available through GSE15805. The DNase-seq data is publicly available through GSE32970 as well as the UCSC genome browser (genome.ucsc.edu) under Regulation::ENCODE DNase/FAIRE::Duke DNaseI HS:LNCaP and LNCaP + Andro. The accession numbers for the ChIP-seq experiments used are GSE14097 and GSE28126.
Project description:Androgens are required for the development of normal prostate, and they are also linked to the development of prostate cancer. We used microarrays to understand the role of androgen in an androgen dependent, androgen receptor (AR) positive human metastatic cell line, LNCaP. LNCaP cells were grown in RPMI medium and they were subjected to stay in phenol-red free, RPMI with charcoal stripped serum for 48h. Synthetic androgen R1881 was added and the cells were allowed to grow for 48h. Control cells were given with corresponding amount of ethanol as vehicle which is used for the solubilization of R1881. Cells were harvested and RNA was isolated for microarray analysis.
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:Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. We identified a novel androgen-regulated long non-coding (lnc) RNA, SOCS2-AS1. In order to investigate the SOCS2-AS1 function in prostate cancer cells, we performed gene expression in AR-positive prostate cancer cell lines (LNCaP and LTAD) after siSOCS2-AS1 or siSOCS2 treatment. We also treated cells with vehicle or androgen to analyzed the effects of siSOCS2-AS1 on AR function. Observation of androgen dependent gene expression changes after treatmet with siSOCS2-AS1 with microarray.
Project description:The androgen receptor is considered as the key promoter of prostate cancer. It is a transcription factor that controls the transcription of hundreds of its target genes. In this project we focuses on how androgen receptor stimulation by the synthetic androgen R1881 can affect the proteome of peroxiosmes and the antioxidant enzymes in LNCaP cells.