A Review of ARID1A’s Role in Breast Cancer Progression: Context-Dependent Mechanisms and Therapeutic Implications

ARID1A, a key subunit of the SWI/SNF chromatin remodeling complex, plays a context-dependent function in cancer, acting both as a tumor suppressor and, in certain conditions, as an oncogene. ARID1A, as a tumor suppressor, maintains transcriptional regulation, genomic stability, and cellular differentiation. In breast cancer, ARID1A loss-of-function leads to dysregulation of cell cycle checkpoints and impaired DNA repair and promotes epithelial-to-mesenchymal transition (EMT), jointly accelerating tumor proliferation and increasing therapeutic resistance. Notably, context-dependent ARID1A loss-of-function often concurs with activation of the PI3K/AKT signaling pathway and corresponds with poor prognosis. On the contrary, aberrant ARID1A overexpression can provoke oxidative stress and agitate the cytochrome P450 system, potentially facilitating early tumorigenesis. Consequently, understanding ARID1A's dual and context-dependent role highlights its potential as a biomarker and therapeutic target in precision oncology.