BRD4

Overview

BRD4 (bromodomain-containing protein 4) is a member of the BET (bromodomain and extra-terminal domain) family of epigenetic reader proteins. It recognizes acetylated lysine residues on histones through its bromodomains and helps regulate chromatin-associated transcription, including RNA polymerase II–mediated gene expression. Because of this role, BRD4 is widely studied as a regulator of cell growth, survival, and oncogenic transcriptional programs.

In biomedical research, BRD4 is an important therapeutic target in cancer and other disease contexts where transcriptional control is dysregulated. Inhibition or degradation of BRD4 can suppress expression of tumor-driving genes, alter signaling pathways such as NF-κB signaling and Wnt/β-catenin pathway-related programs, and affect processes including proliferation, ferroptosis sensitivity, and viral latency-associated protein expression.

Focus of Latest Publications

Recent publications have continued to position BRD4 as a therapeutic target across diverse cancer and virology settings, with many studies focusing on bromodomain inhibition or degradation to disrupt oncogenic transcriptional programs. In pancreatic ductal adenocarcinoma, BRD4 was implicated in the DNA damage response downstream of histone deacetylase 1/2 activity: HDAC inhibition with entinostat redistributed H3K27ac away from DDR gene promoters, reduced BRD4 and RNA polymerase II occupancy, suppressed DDR gene expression, and increased sensitivity to DNA-damaging and DDR-targeting agents. In acute megakaryoblastic leukemia, BRD4 was investigated as a reader of super-enhancer-associated chromatin to identify therapeutic vulnerabilities linked to BRD4-regulated transcriptional dependencies. In metastatic castration-resistant prostate cancer, a dual BRD4/Akt1 inhibitor was developed to address c-MYC-associated resistance, with the lead compound showing nanomolar activity against both targets, suppressing proliferation and migration, inducing G0/G1 arrest and apoptosis, and inhibiting tumor growth in vivo.

Several studies explored BRD4-directed protein degradation as a strategy to overcome resistance or improve delivery. In KSHV-infected immortalized endothelial cells, BRD4 PROTAC degraders MZ-1 and SIM-1 inhibited cell growth, and the effects were linked to suppression of LANA translation through increased eIF2α phosphorylation; RNAi silencing of BRD2 or BRD4 produced similar LANA suppression. In prostate cancer, a nanoengineered PROTAC delivery system carrying ARV-771 was reported to enhance BRD4 degradation while also promoting ferroptosis, with the authors describing a dual mechanism in which BRD4 degradation sensitized tumor cells to ferroptotic death and improved antitumor efficacy with minimal systemic toxicity. Another study reported a short diyne linker that enabled the development of low-nanomolar BRD4 degraders recruiting CRL4CRBN, and the same diyne moiety allowed label-free visualization of intracellular uptake by stimulated Raman scattering microscopy.

BRD4 was also used as a molecular probe in methodological and biophysical studies. A YaxAB nanopore platform was shown to detect BRD4 interactions with histone peptides and diverse small-molecule drugs at the single-molecule level, and to discriminate BRD4-small-molecule drug complexes with mass differences as small as 2.5 Da. This work highlighted near-atomic resolution sensing of protein-ligand interactions and suggested applications in drug discovery and diagnostics. In colorectal cancer-related chemistry efforts, compounds derived from a BRD4-active marine natural product scaffold were optimized into 8-sulfonamidoquinolines with improved antiproliferative activity, although the reported mechanistic work in that study centered on P65, nuclear factor kappa B, and the Wnt/β-catenin pathway rather than BRD4 itself.

Overall, these publications underscore BRD4’s continued relevance as a target for transcriptional repression, targeted degradation, and combination therapy design. Across the studies, BRD4 was linked to DNA damage response control, super-enhancer-driven oncogenic programs, viral latency-associated protein translation, and resistance pathways involving MYC and Akt1, while new chemical and nanotechnological approaches were used to improve selectivity, potency, delivery, and even analytical detection of BRD4-binding events.

Key Publications

• NEWJun HDAC inhibition sensitizes pancreatic tumors to DNA damage by global redistribution of the transcriptional machinery. (Proceedings of the National Academy of Sciences of the United States of America, 2026, PMID 42348617): "HDAC1/2 direct the genomic distribution of H3K27ac, ensuring sufficient BRD4 and RNA polymerase II (Pol II) occupancy at DDR gene promoters."
• NEWJun BRD4 regulation of PIM1 identifies a novel therapeutic vulnerability in acute megakaryoblastic leukemia. (Cancer cell international, 2026, PMID 42310709): "we sought to investigate BRD4 - a key reader of SE-associated chromatin - as a potential therapeutic target in AMKL,"
• Jun Targeting BRD2 and BRD4 inhibit the growth of KSHV-infected immortalized endothelial cells through suppression of LANA translation. (PLoS pathogens, 2026, PMID 42224297): "Members of the bromodomain and extra-terminal domain (BET) family, especially bromodomain-containing protein 4 (BRD4), play important roles in RNA polymerase II-mediated transcriptional regulation and are required for the expression of many tumor-driving oncogenes in various cancer cells."
• Jun A new 4-atom linker enables PROTAC development and imaging. (RSC chemical biology, 2026, PMID 42094781): "Here, we report a series of diyne-bearing, low nanomolar BRD4 degraders recruiting the CRL4CRBN E3 ligase complex."
• May Nanopore Discrimination of Protein-Small-Molecule Drug Complexes at Near-Atomic Resolution. (ACS nano, 2026, PMID 42046448): "we demonstrate that a YaxAB nanopore with LiCl-modulated electrostatic potential enables detection of molecular interactions of the BRD4 protein with histone peptides, as well as diverse small-molecule drugs, at the single-molecule level."
• Apr Dual BRD4/AKT inhibition overcomes c-MYC-driven resistance in metastatic castration-resistant prostate cancer. (European journal of medicinal chemistry, 2026, PMID 41966583): "Bromodomain and extraterminal (BET) inhibitors, such as those targeting BRD4, can disrupt the interaction between BRD4 and chromatin, thereby attenuating c-Myc-driven oncogenic signaling."
• May Nanozyme-Mediated PROTACs Delivery for Targeted Protein Degradation and Ferroptosis Sensitization in Prostate Cancer. (Angewandte Chemie (International ed. in English), 2026, PMID 41870961): "Concurrently, ARV-771-mediated BRD4 degradation sensitizes tumor cells to ferroptosis, establishing a dual-action synergistic mechanism."
• Jun Discovery of 8-sulfonamidoquinolines as anti-proliferative agents against colorectal cancer: design, synthesis, and biological evaluation. (Bioorganic chemistry, 2026, PMID 41763019): "Derivatives based on the marine natural product (MNP) Ammosamide B (1) exhibited potent inhibitory activity against bromodomain-containing protein 4 (BRD4), yet their anti-proliferative effects in cellular assays remained unsatisfactory."