Although mammalian SWI/SNF chromatin remodeling complexes have been well established to play important role in transcription, their role in DNA repair has remained largely unexplored. Here we show that inactivation of the SWI/SNF complexes and downregulation of the catalytic core subunits of the complexes both result in inefficient DNA double-strand break (DSB) repair and increased DNA damage sensitivity as well as a large defect in H2AX phosphorylation (gamma-H2AX) and nuclear focus formation after DNA damage. The expression of most DSB repair genes remains unaffected and DNA damage checkpoints are grossly intact in the cells inactivated for the SWI/SNF complexes. Although the SWI/SNF complexes do not affect the expression of ATM, DNA-PK and ATR, or their activation and/or recruitment to DSBs, they rapidly bind to DSB-surrounding chromatin via interaction with gamma-H2AX in the manner that is dependent on the amount of DNA damage. Given the crucial role for gamma-H2AX in efficient DSB repair, these results suggest that the SWI/SNF complexes facilitate DSB repair, at least in part, by promoting H2AX phosphorylation by directly acting on chromatin.
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http://dx.doi.org/10.1038/sj.emboj.7601291 | DOI Listing |
J Med Chem
January 2025
Foghorn Therapeutics, 500 Technology Square, Suite 700, Cambridge, Massachusetts 02139, United States.
BRM (SMARCA2) and BRG1 (SMARCA4) are mutually exclusive ATPase subunits of the mSWI/SNF (BAF) chromatin remodeling complex. BAF is an attractive therapeutic target because of its role in transcription, and mutations in the subunits of BAF are common in cancer and neurological disorders. Herein, we report the discovery of compound () as a potent allosteric inhibitor of the dual ATPase subunits from a high-throughput screening hit with a BRM IC of ∼27 μM.
View Article and Find Full Text PDFMod Pathol
January 2025
Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, IL. Electronic address:
Deep penetrating nevi (DPNs) are characterized by activating mutations in the MAP kinase and Wnt/beta-catenin pathways that result in large melanocytes with increased nuclear atypia, cytoplasmic pigmentation, and often mitotic activity. Together with a lack of maturation, this constellation of findings creates challenges for pathologists to distinguish deep penetrating nevus (DPN) from DPN-like melanoma. To assess the utility of next generation sequencing (NGS) in resolving this diagnostic dilemma, we performed NGS studies on 35 lesions including 24 DPNs and 11 DPN-like melanomas to characterize the specific genomic differences between the two groups and elucidate the genetic events involved in malignant transformation of DPNs.
View Article and Find Full Text PDFEur J Cancer
November 2024
David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
Purpose: MAK683, a first-in-class and highly selective allosteric inhibitor of the embryonic ectoderm development subunit of polycomb repressive complex 2, has shown sustained antitumor activity in tumor xenograft models. This first-in-human phase 1/2 study evaluated the safety, pharmacokinetics (PK), and clinical activity of single-agent MAK683 in advanced malignancies.
Methods: MAK683 was administered fasted once daily or twice daily continuously in 28-day treatment cycles.
J Cell Mol Med
January 2025
Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi Zhuang Autonomous Region, China.
Bladder cancer originates from bladder tissues and is the ninth most common type of cancer worldwide. The SWI/SNF (SWItch/sucrose non- fermentable) complex plays a crucial role in regulating various biological processes, such as cell cycle control, DNA damage repair and transcription regulation. The purpose of this article is to examine the functional studies of the SWI/SNF complex in bladder cancer, highlighting new pathways for creating personalised treatment approaches for bladder cancer patients with mutations in the SWI/SNF complex.
View Article and Find Full Text PDFThe ARID1A gene, frequently mutated in cancer, encodes the AT-rich interactive domain-containing protein 1A, a key component of the chromatin remodeling SWI/SNF complex. The ARID1A protein features a conserved DNA-binding domain (ARID domain) of approximately 100 residues crucial for its function. Despite the frequency of mutations, the impact on ARID1A's stability and contribution to cancer progression remains unclear.
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