Bromodomain protein BRD4 is required for estrogen receptor-dependent enhancer activation and gene transcription.

ABSTRACT: The estrogen receptor ? (ER?) controls cell proliferation and tumorigenesis by recruiting various cofactors to estrogen response elements (EREs) to control gene transcription. A deeper understanding of these transcriptional mechanisms may uncover therapeutic targets for ER?-dependent cancers. We show that BRD4 regulates ER?-induced gene expression by affecting elongation-associated phosphorylation of RNA polymerase II (RNAPII) and histone H2B monoubiquitination. Consistently, BRD4 activity is required for proliferation of ER(+) breast and endometrial cancer cells and uterine growth in mice. Genome-wide studies revealed an enrichment of BRD4 on transcriptional start sites of active genes and a requirement of BRD4 for H2B monoubiquitination in the transcribed region of estrogen-responsive genes. Importantly, we demonstrate that BRD4 occupancy on distal EREs enriched for H3K27ac is required for recruitment and elongation of RNAPII on EREs and the production of ER?-dependent enhancer RNAs. These results uncover BRD4 as a central regulator of ER? function and potential therapeutic target.

SUBMITTER: Nagarajan S 

PROVIDER: S-EPMC4747248 | biostudies-literature | 2014 Jul

REPOSITORIES: biostudies-literature