OBJECTIVEOvarian cancer is the most deadly gynecologic malignancy worldwide. Since the pathogenesis of ovarian cancer is incompletely understood, and there are no available screening techniques for early detection, most patients are diagnosed with advanced, incurable disease. In an effort to develop innovative and effective therapies for ovarian cancer, we tested the effectiveness of Galecti-3C in vitro. This is a truncated, dominant negative form of Galectin-3, which is thought to act by blocking endogenous Galectin-3.METHODSWe produced a truncated, dominant-negative form of Galectin-3, namely Galetic-3C. Ovarian cancer cell lines and primary cells from ovarian cancer patients were treated with Galectin-3C, and growth, drug sensitivity, and angiogenesis were tested.RESULTWe show, for the first time, that Galectin-3C significantly reduces the growth, motility, invasion, and angiogenic potential of cultured OC cell lines and primary cells established from OC patients.CONCLUSIONSOur findings indicate that Galectin-3C is a promising new compound for the treatment of ovarian cancer.