SOX2 antagonizes WWC1 to drive YAP1 activation in esophageal squamous cell carcinoma

Whether SOX2 and ACTL6A/TP63 interact with the Hippo-YAP1 pathway in esophageal squamous cell carcinoma (ESCC) remains unclear. Here, we reveal that SOX2, ACTL6A, and TP63 are co-amplified and upregulated in ESCC samples. Multiple SOX2 binding peaks in the locus of WWC1, a Hippo-YAP1 regulator, and an inverse correlation between the expression of SOX2 and WWC1 are identified, suggesting direct repression of WWC1 by SOX2. Expression scores of SOX2 are higher in tumors than normal tissues and positively correlated with nuclear YAP1 staining in primary ESCC. Moreover, SOX2 gain-of-function significantly promotes nuclear YAP1 expression in ESCC cells while silencing of SOX2 expression inhibits YAP1 activation. SOX2 overexpression leads to a significant enhancement of cell migration and invasion as well as chemoresistance to cisplatin, whereas knockdown of SOX2 or ectopic expression of WWC1 suppresses the SOX2-induced migration ability and invasive potential. Disruption of this SOX2-WWC1-YAP1 axis could be a therapeutic strategy for SOX2-dependent tumors.