HeLa cell culture

HeLa cells (gifted from Professor Liu Cong; West China Second University Hospital) were cultured in complete DMEM supplemented with 10% fetal bovine serum (both Gibco; Thermo Fisher Scientific, Inc.), 100 U/ml penicillin and 100 µg/ml streptomycin. Cells were harvested by trypsinization and an assessment was made of their density using a hemocytometer to a density of 1.0×10⁵ cells/ml and 5.0×10⁴ cells were added to each well of a 96-well tissue culture-treated plate (Costar; Sigma-Adrich). The cells were inoculated and then incubated at 37°C with 5% CO₂ for 14 days. The DMEM culturing medium was preheated at 37°C in a water bath for a minimum of 30–45 mins to ensure they were at the right temperature, and adherent cells were washed with new pre-warmed media and aspirated to remove any traces of the old media. The media was replaced daily. In the present study, the following groups were used: Control group, which included HeLa cells without any drug treatment; CDV-treated group, in which HeLa cells were treated with an appropriate concentration of CDV (2.5, 5, 10 and 20 µM); and DDP-treated group, in which HeLa cells were treated with an appropriate concentration of DDP (2.5, 5, 10 and 20 µM).