Overexpression of Galectin-3 and its clinical significance in ovarian carcinoma

Background Galectin-3 (Gal-3) is a beta-galactoside-binding lectin involved in regulating cell growth, angiogenesis, and tumor progression. We investigated the clinical significance of Gal-3 expression including its possible use as a prognostic marker or therapeutic target in epithelial ovarian carcinoma (EOC). Methods Gal-3 expression was evaluated by immunohistochemistry in 71 patients with 54 serous, 13 endometrioid, and 4 mucinous ovarian carcinomas. We assessed the correlation of Gal-3 expression with clinical characteristics including histology, optimal debulking, chemosensitivity, and survival. In vitro, Gal-3 was inhibited using siRNA to evaluate its role in cell growth and sensitivity to chemotherapeutic agents in ovarian carcinoma cell lines. Results Gal-3 protein, which was mainly cytoplasmic in location, was observed in a majority (63/71, 88.7%) of the EOCs but not in normal ovarian tissues (P < 0.001). High Gal-3 expression in EOCs correlated with shorter progression-free survival (PFS) of patients (P = 0.039; 43.1 and 49.5 months, respectively). Moreover, cotreatment with Gal-3 siRNA and paclitaxel showed an enhanced cytotoxic effect compared with control siRNA in SKOV3 cells. Conclusion These findings suggest that Gal-3 expression can be a prognostic factor for PFS and may be involved in regulating the response to paclitaxel-based chemotherapy in the treatment of EOC.