TALEN-Engineered AR Gene Rearrangements Reveal Endocrine Uncoupling of Androgen Receptor in Prostate Cancer
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Michael Nyquist
PROVIDER: E-GEOD-49196 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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2012-10-23 | E-GEOD-41784 | biostudies-arrayexpress
Project description:This experiment addressed the question of whether full length Androgen receptor and Androgen Receptor variant ARv567es have similar transciptional activities. The transcriptomes of R1-AD1, a AR full length expressing cell line, are compared in an AR on (1nM DHT) to an AR off (ethanol vehicle) state. R1-D567 was derived from R1-AD1 and modified with TALENs in such a way as to express only AR-V567es. The AR on and off states were induced with a control siRNA (AR on) or a siRNA targeting exon 1 (AR off).
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Project description:The goal of this experiment was to compare the gene expression programs mediated by androgen/AR vs. constitutively active, truncated AR variants in castration-resistant CWR-R1 prostate cancer cells. Because constitutive activity of truncated AR variants can mask androgen/AR target genes, the androgen/AR transcriptional program was assessed by silencing the trucnated AR 1/2/3/CE3 variant with siRNA targeting AR exon CE3 and treating cells with vehicle (ethanol) or 1nM DHT. Similarly, because full-length AR activity can mask truncated AR variant target genes, the AR variant transcriptional program was assessed under castrate conditions by selectively silencing full-length AR with siRNA targeting AR exon 7, and comparing this profile with CWR-R1 cells transfected wtih siRNA targeting AR exon 1, which silences all AR expression (full-length and truncated AR variants).
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Project description:Identifying the effect of the co-chaperone SGTA on global androgen receptor transcriptional activity in C4-2B prostate cancer cells with view to further elucidating the broader biological role of SGTA on other signaling pathways within prostate cancer cells Knockdown of SGTA for 72 hours in C4-2B cells significantly altered the expression of approximately 1900 genes in both vehicle and DHT treated cells. The effect of SGTA knockdown was to suppress the expression of approximately 60% of those transcripts. The regulation of 35% of DHT target genes was also affected by SGTA knockdown, with gene-specific effects on basal, or DHT-induced expression, or both. C4-2B cells were transfected with 5nM non-specific control siRNA (NS) or with a pool of three commercially avaliable SGTA specific siRNA (SGTA) for 72hrs. Cells were subsequently treated with either ethanol vehicle control or 1nM DHT for 16hr. Total RNA was extracted. Five independent vehicle and 2 DHT siNS and siSGTA samples were hybridized to Affymetrix Human Gene 1.0 ST array chips.
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2013-08-26 | E-GEOD-47203 | biostudies-arrayexpress
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Project description:While thousands of long non-coding RNAs (lncRNAs) are expressed in higher eukaryotes, the potential regulatory roles of lncRNAs in regulated gene transcription programs remain rather poorly understood. Here, we report that two lncRNAs highly overexpressed in aggressive prostate cancer, PRNCR1 and PCGEM1, bind successively to the androgen receptor (AR) and strongly enhance both ligand-dependent and ligand-independent AR-mediated gene activation programs and proliferation in prostate cancer cells. Binding of PRNCR1 to the C-terminally acetylated AR on enhancers and its association with DOT1L appear to be required for recruitment of the second lncRNA, PCGEM, to the N-terminally methylated AR. Unexpectedly, recognition of the H3K4me3 promoter mark by the PHD finger-domain of Pygopus2, recruited by PCGEM1, proves to enhance selective looping of AR-bound enhancers to target gene promoters in these cells, revealing a novel aspect of ligand-induced enhancer-promoter interactions. In “resistant” prostate cancer cells, these overexpressed lncRNAs can interact with, and are required for the robust activation of both truncated and full length AR, causing DHT-independent activation of the AR transcriptional program and cell proliferation. Conditionally-expressed short hairpin RNA (shRNA)-mediated targeting of these lncRNAs in these resistant cancer cell lines strongly suppressed xenograft growth in vivo. Together, these results suggest that these overexpressed lncRNAs can potentially serve as a required component of castration-resistance in prostatic tumors. Global Run On (GRO) assay followed by high throughput sequencing (GRO-seq); after knocking-down lincRNAs PCGEM1 and PRNCR1. LNCaP cells were grown to 30-50% confluence and siRNA/ASO transfections were carried out using Lipofectamine 2000 (Invitrogen) according to the manufacturer’s instructions. Control samples were transfected with scramble ASO and control siRNA, respectively. On the following day of transfection, the cells were cultured in UltraCULTURE (Phenol red free) + 5% Charcoal Dextran Stripped (CDS) serum for 48 hours. For androgen induction, we treat cells with DHT from a 100 uM stock in 70% ethanol to a final concentration of 100 nM for 1 hour Scramble ASO, -DHT Scramble ASO, +DHT PRNCR1 ASO, -DHT PRNCR1 ASO, +DHT PCGEM1 ASO, -DHT PCGEM1 ASO, +DHT
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2012-10-02 | E-GEOD-40050 | biostudies-arrayexpress
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