Cell culture. Human Gallbladder carcinoma (GBC) cell line SGC-996 was purchased from the Cell Bank of the Chinese Academy of Science (Shanghai, China). The cells were cultured in complete H-DMEM medium in a humidified atmosphere with 5% CO2 at 37 C. Cells were digested with 0.25% (w/v) trypsin-EDTA (Sigma) for 2 min and centrifuged at 1200 rpm for 5 min.