Novel contribution of acetylated histone variant H2A.Z in activation of neo-enhancers in prostate cancer [Microarray expression]
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE76335 | GEO | 2017/09/05
SECONDARY ACCESSION(S): PRJNA306941
REPOSITORIES: GEO
Similar Datasets
Project description:Acetylation of the histone variant H2A.Z (H2A.Zac) occurs at active promoters and is associated with oncogene activation in prostate cancer, but its role in enhancer function is still poorly understood. Here we show that H2A.Zac containing nucleosomes are commonly redistributed to neo-enhancers in cancer resulting in a concomitant gain of chromatin accessibility and ectopic gene expression. Notably incorporation of acetylated H2A.Z nucleosomes is a pre-requisite for activation of Androgen receptor (AR) associated enhancers. H2A.Zac nucleosome occupancy is rapidly remodelled to flank the AR sites to initiate the formation of nucleosome-free regions and the production of AR-enhancer RNAs upon androgen treatment. Remarkably higher levels of global H2A.Zac correlate with poorer prognosis. Together these data demonstrate the novel contribution of H2A.Zac in activation of newly formed enhancers in prostate cancer.
2017-09-05 | GSE76336 | GEO
Project description:Acetylation of the histone variant H2A.Z (H2A.Zac) occurs at active promoters and is associated with oncogene activation in prostate cancer, but its role in enhancer function is still poorly understood. Here we show that H2A.Zac containing nucleosomes are commonly redistributed to neo-enhancers in cancer resulting in a concomitant gain of chromatin accessibility and ectopic gene expression. Notably incorporation of acetylated H2A.Z nucleosomes is a pre-requisite for activation of Androgen receptor (AR) associated enhancers. H2A.Zac nucleosome occupancy is rapidly remodelled to flank the AR sites to initiate the formation of nucleosome-free regions and the production of AR-enhancer RNAs upon androgen treatment. Remarkably higher levels of global H2A.Zac correlate with poorer prognosis. Together these data demonstrate the novel contribution of H2A.Zac in activation of newly formed enhancers in prostate cancer.
2017-09-05 | GSE76334 | GEO
Project description:We report the high-throughput profiling of histone modifications in prostate cancer cells. By obtaining over 1 billion bases of sequence from chromatin immunoprecipitated DNA, we generated genome-wide chromatin-state maps of prostate cancer cells. we found androgen treatment dismisses a nucleosome over AR binding sites that are flanked by a pair of H3K4me2 marked nucleosomes. A novel quantitative model built on the behavior of such nucleosome pairs correctly identified regions bound by the regulators of the immediate androgen response including AR and FoxA1. More importantly this model also correctly predicted novel binding sites for other transcription factors present following prolonged androgen stimulation including Oct1 and NKX3.1. Thus quantitative modeling of enhancer structure provides a powerful predictive method to infer the identity of transcription factors involved in cellular responses to specific stimuli. Examination of 2 different histone modifications in prostate cancer cells with and without androgen (dihydrotestosterone, DHT) treatment.
2010-03-09 | E-GEOD-20042 | biostudies-arrayexpress
Project description:The discovery that enhancers are regulated transcription units, encoding eRNAs, has raised new questions about the mechanisms of their activation. Here, we report an unexpected molecular mechanism that underlies ligand-dependent enhancer activation, based on DNA nicking to relieve torsional stress from eRNA synthesis. Using dihydrotestosterone (DHT)-induced binding of androgen receptor (AR) to prostate cancer cell enhancers as a model, we show rapid recruitment, within minutes, of DNA topoisomerase I (TOP1) to a large cohort of AR-regulated enhancers. Furthermore, we show that the DNA nicking activity of TOP1 is a prerequisite for robust eRNA synthesis and enhancer activation and is kinetically accompanied by the recruitment of ATR and the MRN complex, followed by additional components of DNA damage repair machinery to the AR-regulated enhancers. Together, our studies reveal a linkage between eRNA synthesis and ligand-dependent TOP1-mediated nicking - a strategy exerting quantitative effects on eRNA expression in regulating AR-bound enhancer-dependent transcriptional programs. Genome-wide binding analysis of AR, TOP1, MRE11 in prostate cancer cell line LNCaP with or without 5alpha-dihydrotestosterone (DHT) treatment. Nascent RNA analysis by global nuclear run-on (GRO-seq) in LNCaP cells transfected with siRNA with or without DHT treatment. Distribution of transcriptionally engaged RNA Pol II in LNCaP cells with or without DHT treatment by precision nuclear run-on and sequencing (PRO-seq).
2015-01-22 | E-GEOD-63202 | biostudies-arrayexpress
Project description:We report the high-throughput profiling of histone modifications in prostate cancer cells. By obtaining over 1 billion bases of sequence from chromatin immunoprecipitated DNA, we generated genome-wide chromatin-state maps of prostate cancer cells. we found androgen treatment dismisses a nucleosome over AR binding sites that are flanked by a pair of H3K4me2 marked nucleosomes. A novel quantitative model built on the behavior of such nucleosome pairs correctly identified regions bound by the regulators of the immediate androgen response including AR and FoxA1. More importantly this model also correctly predicted novel binding sites for other transcription factors present following prolonged androgen stimulation including Oct1 and NKX3.1. Thus quantitative modeling of enhancer structure provides a powerful predictive method to infer the identity of transcription factors involved in cellular responses to specific stimuli.
2010-03-09 | GSE20042 | GEO
Project description:Reactivation of androgen receptor (AR) may drive recurrent prostate cancer in castrate patients. Ack1 tyrosine kinase is overexpressed in prostate cancer and promotes castrate resistant xenograft tumor growth and enhances androgen target gene expression and AR recruitment to enhancers. Ack1 phosphorylates AR at Tyr-267 in the N-terminal transactivation domain. In this study, the role of this phosphorylation site was investigated by characterizing the phosphorylation site mutant in the context of full length and truncated AR lacking the ligand-binding domain. The Y267F mutant showed decreased transactivation of reporters. Expression of wild type full length and truncated AR in LNCaP cells increased cell proliferation in androgen-depleted conditions and increased colony formation. However, the Y267F mutant of full length and truncated AR was defective in stimulating cell proliferation. The full length AR Y267F mutant was defective in nuclear translocation induced by androgen or Ack1 kinase. The truncated AR was constitutively localized to the nucleus. Chromatin immunoprecipitation analysis showed that it was recruited to the target enhancers without androgen. The truncated Y267F AR mutant did not exhibit constitutive nuclear localization and androgen enhancer binding activity. Expression of AR responsive genes in cells expressing truncated AR wt and AR-Y267F mutant under androgen deprived conditions was assessed by microarray gene expression analysis. The AR pathway score was increased in cells expressing truncated AR wt and decreased in cells expressing truncated AR-Y267F. These results support the concept that phosphorylation of Tyr-267 is required for AR nuclear translocation and recruitment and DNA binding and transcription of AR responsive genes. Gene expression profiling was performed using RNA samples from LNCaP cells expressing truncated AR-wt and truncated AR-Y267F growing in androgen deprived conditions. The RNA sample from vector control cells were used as reference sample. Two biological replicates were used per each cell line.
2015-06-10 | E-GEOD-69712 | biostudies-arrayexpress
Project description:Mammalian genomes are populated with thousands of transcriptional enhancers that orchestrate cell type-specific gene expression programs; however, the potential that there are pre-established enhancers in different functional classes that permit alternative signal-dependent transcriptional responses has remained unexplored. Here we present evidence that cell lineage-specific factors, such as FoxA1, can simultaneously facilitate and restrict key regulated transcription factors, exemplified by the androgen receptor (AR), acting at structurally- and functionally-distinct classes of pre-established enhancers, thus licensing specific signal-activated responses while restricting others. Consequently, FoxA1 down-regulation, an unfavorable prognostic sign in advanced prostate tumors, causes a massive switch in AR binding from one functional class of enhancers to another, with a parallel switch in levels of enhancer-templated non-coding RNAs (eRNAs) revealed by the global run-on assay (GRO-seq), which documents the dramatic reprogramming of the hormonal response. The molecular basis for this switch lies in the release of FoxA1-mediated restriction of AR binding to the new enhancer class with no apparent nucleosome remodeling, which is required for stimulating their eRNA transcription and/or enhancing enhancer:promoter looping and gene activation. Together, these findings reveal a large repository of pre-determined enhancers in the human genome that can be dynamically tuned to induce their transcription and activation of alternative gene expression programs, which may underlie many sequential gene expression events in development or during disease progression. ChIP-Seq, Gro-Seq, and gene expression profiling was performed in LNCaP cells with hormone treatment and siRNA against FoxA1. Gene expression profiling data presented here.
2011-05-15 | E-GEOD-27682 | biostudies-arrayexpress
Project description:Androgen receptor (AR) is required for castration resistant prostate cancer (CRPC) progression, but the function and disease relevance of AR-bound enhancers remain poorly understood. Here, we identify a group of AR-regulated enhancer RNAs (e.g. PSA eRNA) that are upregulated in CRPC cells, patient-derived xenografts (PDX) and patient tissues. PSA eRNA binds to CYCLIN T1, activates P-TEFb and promotes in cis and trans gene transcription by increasing serine-2 phosphorylation of RNA polymerase II (Pol II-Ser2p). To avoid the total Pol II changing by PSA eRNA. We measured the total Pol II using N20 and 8WG16 antibodies with or without PSA eRNA knocking down. To avoid the AR binding changes by PSA eRNA, we also measured the AR binding using AR N20 antibodies with or without PSA eRNA knocking down. Androgen receptor (AR) binding sites in human prostate cancer cell lines, C4-2, were studied using ChIP-seq. Total Pol II Ser-2p and AR binding sites in human prostate cancer cell lines C4-2 with or without PSA eRNA knockdown, were studied using ChIP-seq. ChIP enriched DNA were sequenced using Illumina HiSeq 2500and input DNA were sequenced using Illumina HiSeq 2000.
2016-02-12 | E-GEOD-71704 | biostudies-arrayexpress
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 PYGO2 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 Control siRNA, -DHT Control siRNA, +DHT Pygo2 siRNA, -DHT Pygo2 siRNA, +DHT
2013-08-15 | E-GEOD-47805 | biostudies-arrayexpress
Project description:Mammalian genomes are populated with thousands of transcriptional enhancers that orchestrate cell type-specific gene expression programs; however, the potential that there are pre-established enhancers in different functional classes that permit alternative signal-dependent transcriptional responses has remained unexplored. Here we present evidence that cell lineage-specific factors, such as FoxA1, can simultaneously facilitate and restrict key regulated transcription factors, exemplified by the androgen receptor (AR), acting at structurally- and functionally-distinct classes of pre-established enhancers, thus licensing specific signal-activated responses while restricting others. Consequently, FoxA1 down-regulation, an unfavorable prognostic sign in advanced prostate tumors, causes a massive switch in AR binding from one functional class of enhancers to another, with a parallel switch in levels of enhancer-templated non-coding RNAs (eRNAs) revealed by the global run-on assay (GRO-seq), which documents the dramatic reprogramming of the hormonal response. The molecular basis for this switch lies in the release of FoxA1-mediated restriction of AR binding to the new enhancer class with no apparent nucleosome remodeling, which is required for stimulating their eRNA transcription and/or enhancing enhancer:promoter looping and gene activation. Together, these findings reveal a large repository of pre-determined enhancers in the human genome that can be dynamically tuned to induce their transcription and activation of alternative gene expression programs, which may underlie many sequential gene expression events in development or during disease progression. ChIP-Seq, Gro-Seq, and gene expression profiling was performed in LNCaP cells with hormone treatment and siRNA against FoxA1 ChIP-Seq and Gro-Seq data presented here. Supplementary file GroSeq.denovo.transcripts.hg18.bed represents analysis using GSM686948-GSM686950.
2011-05-15 | E-GEOD-27823 | biostudies-arrayexpress