Galectin-3 accelerates the progression of oral tongue squamous cell carcinoma via a Wnt/β-catenin-dependent pathway.

The purpose of this study was to elucidate the clinicopathological significance and mechanism of action of galectin-3 in oral tongue squamous cell carcinoma (OTSCC). Here, the expression of galectin-3 was quantified in OTSCC (n = 68) and paired OTSCC and normal surrounding tissues (n = 10) using immunohistochemical staining. Tca8113 OTSCC cells were transfected with a plasmid expressing galectin-3 cDNA or siRNA against galectin-3. Cell proliferation, migration and invasion were measured using the MTT assay, Matrigel-coated Transwell migration assay and wound healing assay. The effect of galectin-3 on the Wnt/β-catenin signaling pathway and epithelial mesenchymal transition (EMT) were investigated using a plasmid expressing the Wnt antagonist dickkopf 1 (DKK1) and Western blotting. Galectin-3 was expressed at significantly higher levels in OTSCC than the normal adjacent tissues; galectin-3 expression correlated strongly with pathological stage, pathological grade and lymph node invasion in OTSCC. Overexpression of galectin-3 promoted Tca8113 cell proliferation, migration and invasion, upregulated Wnt protein expression, activated β-catenin and induced the EMT; knockdown of galectin-3 had the opposite effects. Co-transfection of Tca8113 cells overexpressing galectin-3 with the Wnt antagonist DKK1 reduced the ability of galectin-3 to increase cell proliferation, migration and invasion, reduced upregulation of Wnt, inhibited β-catenin activation and abrogated the EMT, demonstrating that the Wnt/β-catenin signaling pathway mediated the effects of galectin-3. Galectin-3 plays an important role in the progression of OTSCC via activation of the Wnt/β-catenin signaling pathway.