ARID1A restrains EMT and stemness of ovarian cancer cells through the Hippo pathway.

ABSTRACT

Genes encoding subunits of SWI/SNF (BAF) chromatin­remodeling complexes are recurrently mutated in a broad array of tumor types, and among the subunits, ARID1A is the most frequent target with mutations. In the present study, it was reported that ARID1A inhibits the epithelial­mesenchymal transition (EMT) and stemness of ovarian cancer cells, accompanied by reduced cell viability, migration and colony formation, suggesting that ARID1A acts as a tumor suppressor in ovarian cancer. Mechanistically, ARID1A exerts its inhibitory effects on ovarian cancer cells by activating the Hippo signaling pathway. Conversely, the overexpression of a gain­of­function transcriptional co­activator with PDZ­binding motif (TAZ) mutant (TAZ­Ser89) effectively reverses the effects induced by ARID1A. In addition, activation of Hippo signaling apparently upregulates ARID1A protein expression, whereas ectopic expression of TAZ­Ser89 results in the markedly decreased ARID1A levels, indicating a feedback of ARID1A­TAZ in regulating ovarian cancer cell EMT and stemness. Thus, the present study uncovered the role of ARID1A through the Hippo/TAZ pathway in modulating EMT and stemness of ovarian cancer cells, and providing with evidence that TAZ inhibitors could effectively prevent initiation and metastasis of ovarian cancer cases where ARID1A is lost or mutated.