SOX2 promotes tumor metastasis by stimulating epithelial-to-mesenchymal transition via regulation of WNT/β-catenin signal network

SOX2 was reported to promote metastasis in various tumor tissues; however the underlying mechanisms remain elusive. Here, we disclosed that SOX2 improves metastasis of breast and prostate cancer cells by promoting epithelial-to-mesenchymal transition (EMT) through WNT/β-catenin, but not TGF-β or Snail1 signaling. Dual luciferase assay and chromatin immunoprecipitation revealed activation and binding of SOX2 on promoter region of β-catenin. In addition, SOX2 affects the protein expression levels of DKK3, DVL1 and DVL3, which are regulators or downstream molecules of WNT signaling. Taken together, our findings demonstrated β-catenin as one of vital downstream molecules that mediate the EMT induced by SOX2.