SMARCA4: Promises and challenges in the treatment of cancers

The SWI/SNF (switch/sucrose non-fermentable) related BAF (BRG1/BRM-related factor) chromatin remodeling complex subunit ATPase 4 (SMARCA4) is a gene with a high mutation frequency in the SWI/SNF complex. It plays a role as an ATP-dependent catalytic subunit, participates in remodeling chromatin structure and regulation of gene expression, and is closely related to the poor prognosis of malignant tumors. It is imperative to conduct a comprehensive investigation into the distinctive biological functions and mechanisms by which SMARCA4 contributes to cancer development and to devise targeted therapeutic strategies. Despite numerous studies associating SMARCA4 with the regulation of essential genes, ferroptosis, autophagy, lipid metabolism, and oxidative stress, the precise mechanisms of SMARCA4 in tumors remain unclear. Patients with SMARCA4 mutations exhibit a poor prognosis and demonstrate limited responsiveness to surgery, targeted therapies, immunotherapy, and chemotherapies. Thus, SMARCA4 emerges as a promising biomarker and therapeutic target. However, the development of more effective precision therapy tools remains an urgent unmet need. The unique molecular characteristics of SMARCA4 pose significant challenges for targeted drug development. Notably, the discovery of inhibitors targeting SMARCA4 synthetic lethal partners and associated pathways has marked a breakthrough in this field. Monotherapies directed against SMARCA4 face several limitations, including drug resistance, suboptimal objective response rates, and dose-limiting toxicities. Consequently, the exploration of combinatorial therapeutic strategies for SMARCA4 deficiency populations represents a critical direction for future clinical translation.