Targeting the Bcl-2 family and P-glycoprotein reverses paclitaxel resistance in human esophageal carcinoma cell line.

Paclitaxel (PTX) is one of the most effective drugs used in the treatment of esophageal cancer, however, paclitaxel resistance represents a key limitation during the treatment process. In this study, we investigated the changes of Bcl-2 family members in the moderate paclitaxel-resistance of esophageal carcinoma EC109/PTX cells both in vitro and in vivo. Moreover, we evaluated the reversal effect using siRNAs and the recombinant inhibitor TW37 targeting Bcl-2, Bcl-XL and Mcl-1. Our findings show that downregulation of Bcl-2, Bcl-XL and Mcl-1 can significantly promote EC109/PTX cell apoptosis and reduce the EC109/PTX cell resistance index (RI). Furthermore, TW37 in combination with a P-gp inhibitor can synergistically reverse the paclitaxel resistance in EC109/PTX cells. These results suggest that targeting of the Bcl-2 family and P-gp is capable of reversing the resistance in EC109/PTX cells and the two-inhibitor combination may be a novel treatment strategy for resistant esophageal cancer.