Study on Antitumor Activity of Polyphyllin I with Hyperthermia on Human Gastric Cancer Cell Lines MKN-45 in Vitro

Objective:To evaluate the antitumor activity of PPⅠ with hyperthermia on human gastric cancer cell lines MKN-45 in vitro.Methods:Human gastric cancer MKN-45 cells were cultured and treated with different concentrations of PPⅠ with or without hyperthermia.Cell proliferation and apoptosis were measured by MTT assay and flow cytometry.The influence of hyperthermia on the antitumor effects of PPⅠ was measured by colony formation assay.The p21 protein levels were assessed by western blot analyses.Results:The survival rates of MKN-45 cells were significantly decreased after 24 and 48 hours culturing with different concentrations of PPⅠ,and this effect exhibited time-dose-dependent.Apoptosis rate was increased from(4.3±1.1)% to(37.8±3.5)% after culturing with PPⅠ for 24 hours.Compared with PPⅠ alone,when combined with hyperthermia,cell survival rate was decreased from(61.2±3.4)% to(40.7±3.1)%(P0.05).The expression of p21 protein can be upregulated by PPⅠ and this effect can be enhanced by hyperthermia.Conclusion:PPⅠ exhibits growth inhibition and apoptosis induction in human gastric cancer cell lines MKN-45,and the effects can be enhanced by hyperthermia.The antitumor mechanism may be related to upregulating the expression of p21 protein.