Transcriptional addiction in cancer cells is mediated by YAP/TAZ through BRD4

October 1, 2018

... tected using the Fast Red detection reagent. RT-qPCR Total RNA extraction from cells and tissue was performed with NucleoSpin 8 RNA Core Kit (Macherey-Nagel, REF.740465.4) using an automated system (Freedom EVO, Tecan). Contaminant DNA was removed by rDNase Set (Macherey-Nagel, REF.740963). Pancreatic acini were harvested in TriPure (Roche) for total RNA extraction.cDNA synthesis was carried out ... e treated with different doses of JQ1 (1nM, 10nM, 0.1µM and 1µM). Cells were harvested after 24h of treatment (day2). Firefly luciferase activity was measured with an Infinite F200PRO plate reader (TECAN), using Luciferin (Sigma) as substrate. Data are presented as firefly/β-gal activity. Each sample was transfected in duplicate and each experiment was repeated at least three times independentl

Cancer cells rely on dysregulated gene expression. This establishes specific transcriptional addictions that may be therapeutically exploited. Yet, the mechanisms that are ultimately responsible for these addictions are poorly understood. Here, we investigated the transcriptional dependencies of transformed cells to the transcription factors YAP and TAZ. YAP/TAZ physically engage the general coactivator bromodomain-containing protein 4 (BRD4), dictating the genome-wide association of BRD4 to chromatin. YAP/TAZ flag a large set of enhancers with super-enhancer-like functional properties. YAP/TAZ-bound enhancers mediate the recruitment of BRD4 and RNA polymerase II at YAP/TAZ-regulated promoters, boosting the expression of a host of growth-regulating genes. Treatment with small-molecule inhibitors of BRD4 blunts YAP/TAZ pro-tumorigenic activity in several cell or tissue contexts, causes the regression of pre-established, YAP/TAZ-addicted neoplastic lesions and reverts drug resistance. This work sheds light on essential mediators, mechanisms and genome-wide regulatory elements that are responsible for transcriptional addiction in cancer and lays the groundwork for a rational use of BET inhibitors according to YAP/TAZ biology.

Zanconato, F; Battilana, G; Forcato, M; Filippi, L; Azzolin, L; Manfrin, A; Quaranta, E; Di Biagio, D; Sigismondo, G; Guzzardo, V; Lejeune, P; Haendler, B; Krijgsveld, J; Fassan, M; Bicciato, S; Cordenonsi, M; Piccolo, S;

Journal: Nat. Med. Pages: 1599-1610

Original article (30224758)