BRD4, a Bromodomain and Extraterminal (BET) protein family member, is a promising anti-cancer drug target. However, resistance to BET inhibitors targeting BRD4 is common in solid tumors. Here, we show that cancer-associated fibroblast (CAF)-activated stromal signaling, interleukin-6/8-JAK2, induces BRD4 phosphorylation at tyrosine 97/98 in colorectal cancer, resulting in BRD4 stabilization due to interaction with the deubiquitinase UCHL3. BRD4 phosphorylation at tyrosine 97/98 also displays increased binding to chromatin but reduced binding to BET inhibitors, resulting in resistance to BET inhibitors. We further show that BRD4 phosphorylation promotes interaction with STAT3 to induce chromatin remodeling through concurrent binding to enhancers and super-enhancers, supporting a tumor-promoting transcriptional program. Inhibition of IL6/IL8-JAK2 signaling abolishes BRD4 phosphorylation and sensitizes BET inhibitors in vitro and in vivo. Our study reveals a stromal mechanism for BRD4 activation and BET inhibitor resistance, which provides a rationale for developing strategies to treat CRC more effectively.
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http://dx.doi.org/10.1038/s41467-021-24687-4 | DOI Listing |
PLoS Genet
December 2024
Department of Biology of the Cell Nucleus, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic.
Mol Cell
November 2024
Science for Life Laboratory, Stockholm, Sweden; Department of Gene Technology, KTH Royal Institute of Technology, Stockholm, Sweden. Electronic address:
In this issue, Devaiah et al. identify JNK-catalyzed phosphorylation to convert bromodomain-containing protein 4 (BRD4) from a chromatin regulator to a transcription activator.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Department of Hematology, The First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China. Electronic address:
Ferroptosis has emerged as a critical mechanism in the development and progression of various tumors, particularly diffuse large B-cell lymphoma (DLBCL). However, the thorough characterization of ferroptosis-related genes in DLBCL remains inadequately explored. We retrieved datasets associated with DLBCL and ferroptosis gene sets from the Gene Expression Omnibus (GEO) database and the Ferroptosis Database (FerrDb), resulting in the identification of 27 differentially expressed ferroptosis-related genes (DE-FRGs) linked to DLBCL.
View Article and Find Full Text PDFMol Cell
November 2024
Experimental Immunology Branch, NCI, NIH, Bethesda, MD 20892, USA. Electronic address:
Bromodomain 4 (BRD4), a key regulator with pleiotropic functions, plays crucial roles in cancers and cellular stress responses. It exhibits dual functionality: chromatin-bound BRD4 regulates remodeling through its histone acetyltransferase (HAT) activity, while promoter-associated BRD4 regulates transcription through its kinase activity. Notably, chromatin-bound BRD4 lacks kinase activity, and RNA polymerase II (RNA Pol II)-bound BRD4 exhibits no HAT activity.
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