SUMMARY
Proinflammatory stimuli elicit rapid transcriptional responses via transduced signals to master regulatory transcription factors. To explore the role of chromatin-dependent signal transduction in the atherogenic inflammatory response, we characterized the dynamics, structure and function of regulatory elements in the activated endothelial cell epigenome. Stimulation with tumor necrosis factor alpha prompted a dramatic and rapid global redistribution of chromatin activators to massive de novo clustered enhancer domains. Inflammatory super enhancers formed by NF-κB accumulate at the expense of immediately decommissioned, basal endothelial super enhancers, despite persistent histone hyperacetylation. Mass action of enhancer factor redistribution causes momentous swings in transcriptional initiation and elongation. A chemical genetic approach reveals a requirement for BET bromodomains in communicating enhancer remodeling to RNA polymerase and orchestrating the transition to the inflammatory cell state, demonstrated in activated endothelium and macrophages. BET bromodomain inhibition abrogates super enhancer mediated inflammatory transcription, atherogenic endothelial responses and atherosclerosis in vivo.
SUMMARY
Clear cell renal cell carcinoma (ccRCC) is the most common form of kidney cancer and is often linked to loss of chromosome 3p, which harbors the VHL tumor suppressor gene, loss of chromosome 14q, which includes HIF1A, and gain of chromosome 5q. The relevant target(s) on chromosome 5q is not known. Here we show that 5q amplification leads to overexpression of the SQSTM1 oncogene in ccRCC lines and tumors. Overexpression of SQSTM1 in ccRCC lines promoted resistance to redox stress and increased soft agar growth while downregulation of SQSTM1 decreased resistance to redox stress, impaired cellular fitness, and decreased tumor formation. Therefore the selection pressure to amplify 5q in ccRCC is driven, at least partly, by SQSTM1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.