Polybromo 1 (PBRM1)

Polybromo 1 (PBRM1) is a subunit of the PBAF (Polybromo-associated–BRG1-associated factor) SWI/SNF chromatin-remodeling complex and plays a critical role in chromatin remodeling and transcriptional regulation by affecting DNA-nucleosome topology[1][3]. It contains multiple bromodomains and participates in regulating gene expression, cell proliferation, and cell adhesion, affecting cellular processes such as apoptosis, metabolism, and response to hypoxia[2][3]. PBRM1 functions as a tumor suppressor, most notably in clear cell renal cell carcinoma, where mutations or deletions of the gene are highly prevalent and may serve as early drivers of carcinogenesis[1][2][6]. Loss of PBRM1 is associated with distinct gene expression and immune signatures in cancers and is explored as a prognostic and predictive biomarker, particularly regarding responses to immune-based therapies[4][8]. There are currently no drugs that directly target PBRM1, but its status is important for the stratification and management of cancer patients, especially in kidney cancers.

Other names

BRG1-associated factor 180BAF180PB1SMARCH1

Loss of PBRM1 sensitizes tumors to immune checkpoint blockade by modulating tumor microenvironment and immune signaling