Autophagy Induced by Naftopidil Inhibits Apoptosis of Human Gastric Cancer Cells

Naftopidil is used to treat benign prostate hyperplasia. Moreover, previous studies have shown that naftopidil reduced viability of many types of cancer cells. Therefore, we investigated the antitumor mechanism of naftopidil in this study. We used the HGC27 human gastric cancer cell line. It was treated with naftopidil, pan-caspase inhibitor, and chloroquine diphosphate (CQ). Cell viability and cell death were investigated by the assay and annexin V/ propidium iodide assay. Phosphorylation of protein kinase B (AKT) (Ser473) was measured by western blotting. Alteration of light chain 3B (LC3B) was investigated by western blotting and immunofluorescence. Naftopidil reduced phospho-AKT (Ser473) and altered LC3B. Combination of naftopidil and CQ reduced cell viability and phospho-AKT (Ser 473). Naftopidil induces apoptosis and autophagy of HGC27 cells, however, autophagy is considered to inhibit apoptosis. We concluded naftopidil and CQ have a synergistic antitumor effect.