Dataset Information

BRD4 Chromatin immunoprecipitation and Sequencing

ABSTRACT: We report BET bromodomain inhibitors (BETi) as regulators of keratinocyte stem cell fate. BETi displace BET proteins, including BRD4 from chromatin, inducing acute transcriptional changes at selected target genes. To gain insight into the compound mechanism of action, we assayed BRD4 chromatin occupancy genome-wide in keratinocytes subjected to BETi treatment. Specifically, BRD4 chromatin binding was analyzed following two treatments [125nM (low) versus 1250nM (high)] and three time points (30min, 6h and 6h treatment followed by compound removal for 3h (6m3h)).

ORGANISM(S): Homo sapiens

PROVIDER: GSE130365 | GEO | 2020/10/15

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Targeting the epigenome to modulate gene expression programs driving cancer development has emerged as an exciting avenue for therapeutic intervention. Pharmacological inhibition of the bromodomain and extraterminal (BET) family of chromatin adapter proteins has proven effective in this regard, suppressing growth of diverse cancer types mainly through downregulation of the c-MYC oncogene and its downstream transcriptional program. While initially effective, resistance to BET inhibitors (BETi) typically occurs through mechanisms that reactivate MYC expression. We have previously shown that lung adenocarcinoma (LAC) is inhibited by JQ1 through suppression of FOSL1, suggesting that the epigenetic landscape of tumor cells from different origins and differentiation states influences BETi response. Here, we assessed how these differences affect mechanisms of BETi resistance through the establishment of isogenic pairs of JQ1 sensitive and resistant LAC cell lines. We found that resistance to JQ1 in LAC occurs independent of FOSL1 while MYC levels remain unchanged between resistant cells and their JQ1 treated parental counterparts. Furthermore, while epithelial-mesenchymal transition (EMT) is observed upon resistance, TGF- induced EMT did not confer resistance in JQ1 sensitive LAC lines, suggesting this is a consequence, rather than a driver of BETi resistance in our model systems. Importantly, siRNA knockdown demonstrated that JQ1 resistant cell lines are still dependent on BRD4 expression and we found that phosphorylation of BRD4 is elevated in resistant LACs, identifying casein kinase 2 (CK2) as a candidate protein mediating this effect. Inhibition of CK2, as well as downstream transcriptional targets of phosphorylated BRD4 - including AXL and activators of the PI3K pathway - synergize with JQ1 to inhibit BETi resistant LAC. Overall, this demonstrates that the mechanism of resistance to BETi varies depending on cancer type, with LAC cells developing JQ1 resistance independent of MYC re-activation, and identifying CK2 phosphorylation of BRD4 as a potential target to overcome resistance in this cancer.

Dataset Information

BRD4 Chromatin immunoprecipitation and Sequencing

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets