Galectin-3 regulates chemotherapy sensitivity in epithelial ovarian carcinoma via regulating mitochondrial function.

Galectin-3 (Gal-3) is a multifunctional carbohydrate-binding protein associated with cell migration, cell proliferation, cell adhesion, and cell-cell interaction in tumor cells. It has been implied to be involved in the tumor progression and chemoresistance of epithelial ovarian cancer (EOC). However, it is unclear whether the Gal-3-mediated regulation on the EOC chemosensitivity is associated with hypoxia or mitochondrial dysfunction. In the present study, we examined the regulation by Gal-3 overexpression on cisplatin-sensitivity or cisplatin-resistance in EOC cells in vitro. We manipulated Gal-3 via plasmid transfection and RNA interference in the cisplatin-resistant EOC cells, and re-evaluated the sensitivity of the cisplatin-resistant EOC cells to cisplatin, with CCK-8 assay, colony forming assay, apoptosis analysis and mitochondrial function examination. Results demonstrated that galectin-3 overexpression downregulated the cisplatin sensitivity in EOC OVCAR-3 cell clone, resulting in an upregulated growth and a reduced apoptosis in the cisplatin-treated OVCAR-3 cells. On the other hand, the Gal-3 knockdown with Gal-3-specific siRNA transfection aggravated cisplatin-induced apoptosis in OVCAR-3 cells. In conclusion, Galectin-3 reduces the sensitivity of ovarian cancer cells to cisplatin via regulating cisplatin-induced mitochondrial dysfunction. Galectin-3 knockdown inhibits the chemo-resistance of EOC cells. It implies that Galectin-3 might be a potential target to overcome the chemo-resistance in EOC cells.