Inhibition of autophagy by bafilomycin A1 promotes chemosensitivity of gastric cancer cells.

Autophagy is an intracellular degradation pathway that delivers organelles or protein to the lysosome and has been recently implicated in the resistance of gastric cancer to chemotherapy. This study aimed to investigate whether blocking autophagy is a new approach for the treatment of chemoresistant gastric cancer. SGC-7901 gastric cancer cell line was treated with 5-fluorouracil (5-FU) or/and autophagy inhibitor bafilomycin A1. Cell viability and growth were evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) and clonogenic assay. Apoptosis was evaluated by flow cytometry. Cell migratory and invasive ability were evaluated by migration and invasion assays. Autophagy was evaluated by scanning electron microscopic, acridine orange staining, and Western blot analysis. We observed that 5-FU induced autophagy in SGC-7901 cells. Bafilomycin A1 decreased the viability and clone formation, inhibited the invasive and migratory ability, and increased the apoptosis of SGC-7901 cells. Taken together, our data suggest that chemotherapy-induced autophagy contributes to gastric cancer chemoresistance, and the inhibition of autophagy is a promising strategy for gastric cancer therapy.