BRIT1 (breast cancer susceptibility gene C terminus-repeat inhibitor of human telomerase repeat transcriptase expression), a tumor suppressor and early DDR factor, is recruited to DNA double-strand breaks (DSBs) by phosphorylated H2A histone family, member X (γ-H2AX), where it promotes chromatin relaxation by recruiting the switch/sucrose nonfermentable (SWI-SNF) chromatin remodeler to facilitate DDR.
BRG1, a core component of the SWI/SNF chromatin-remodeling complex, has been implicated in cancer development; however, the biological significance of BRG1 in breast cancer remains unknown.