Polypeptide A28 enhances cytotoxic effect of cisplatin on colon cancer cell line HCT-116

Objective To study the effect of polypeptide A28,which was designed by computer aided drug designing system,on the cytotoxic effect of cisplatin against colon cancer cells.Methods: Colon cancer cell line HCT-116 and human umbilical vein endothelial cells(HUVEC) were used in the present study.The concentration of polypeptide A28 was 20 μmol /L and those of cisplatin were 10,30 and 90 μmol/L.The effects of polypeptide A28 combined with cisplatin on the growth of HCT-116 and HUVEC cells were measured by MTT;their effects on the apoptosis of HCT-116 cells were examined by flow cytometry.Results:Cisplatin dose-dependently inhibited proliferation of HCT-116 cells;A28 further enhanced the inhibitory effect of cisplatin on HCT-116 cells and increased apoptosis induction effect of cisplatin on HCT-116 cells,with the growth inhibition rate of the combination group being(43.3±0.03)%,which was significantly higher than that of the cisplatin single group(15.6±0.10)%(P0.01).In combination group,when cisplatin concentrations(30,90 μmol/L) were increased,the inhibitory effects on HCT-116 cells were not increased compared with the 10 μmol/L cisplatin combination group(P0.05).A28 combined with cisplatin(1.1,3.3,10,30,or 90 μmol/L) induced apoptosis of more HCT-116 cells than cisplatin single group did(P0.01).Csplatin at 10 μmol/L combined with A28 at 20 μmol/L effectively killed HCT-116 cells,whereas with less toxic effect on HUVEC cells.Conclusion:Polypeptide A28 can enhance the cytotoxic effect of cisplatin on colon cancer cell line HCT-116 and decrease its lethal effect on HUVEC.