Effects of genistein combined with cisplatin on drug-resistant ovarian carcinoma cell SKOV-3

AIM: To investigate the effects of genistein combined with cisplatin on the proliferation and apoptosis of drug- resistant ovarian carcinoma cell SKOV-3. METHODS: The growth inhibitory effect of genistein and cisplatin on SKOV-3 cells was studied by MTT growth assay, the morphological alterations of SKOV-3 cells were demonstrated by Hoechst 33342 staining under a fluorescence microscope and apoptosis and cell cycle distribution were detected by flow cytometry. RESULTS: Various concentrations of genistein in combination with cisplatin resulted in the reduction of IC_ 50 by 32.3%-79.8% in SKOV-3 cells. The combination index of genistein and cisplatin in SKOV-3 cells ranged from 0.586 to 0.869, which indicated that they acted in a slightly to highly synergistic pattern. The apoptotic rate was also significantly raised by combination of genistein and cisplatin, which showed a relationship with G2/M arrest and the disturbance of S phase because there was a negative correlation between apoptotic rate and G1 phase cell fraction(r_s=-0.953, P0.05). CONCLUSION: Genistein can significantly improve the growth inhibition and cytotoxicity effects of cisplatin on SKOV-3 cells and the two agents act in a synergistic way. These synergistic effects may be related to the G2/M arrest and the disturbance of S phase by genistein.