Synergistic Effects of PectaSol-C Modified Citrus Pectin an Inhibitor of Galectin-3 and Paclitaxel on Apoptosis of Human SKOV-3 Ovarian Cancer Cells

Galectin-3 (Gal-3) is a carbohydrate-binding protein which is thought to be involved in cancer progressionbut its contribution to epithelial ovarian cancer (EOC) remains unclear. The present study sought to determinethe role of Gal-3 in chemoresistance of the human SKOV-3 ovarian cancer cell line to paclitaxel (PTX) usingrecombinant human Gal-3 (rhGal-3) and PectaSol-C modified citrus pectin (Pect-MCP) as a specific Gal-3competitive inhibitor. Our results showed 41% increased cell proliferation, 36% decreased caspase-3 activityand 33.6% increased substrate-dependent adhesion in the presence of rhGal-3 compared to the control case(p<0.001). Treatment of cells with a non-effective dose of PTX (100nM) and 0.1% Pect-MCP in combinationrevealed synergistic cytotoxic effects with 75% reduced cell viability and subsequent 3.9-fold increase in caspase-3activity. Moreover, there was 39% decrease in substrate-dependent adhesion compared to control (p<0.001).These results suggest that inhibition of Gal-3 could be a useful therapeutic tool for combination therapy ofovarian cancer.