Inhibitory effects of genistein on proliferation in human ovarian carcinoma cell line 3AO and related mechanism

AIM: To investigate the effects of genistein on proliferation inhibition and apoptosis induction in human ovarian carcinoma cell line 3AO and to explore its anti-cancer mechanism. METHODS: After cultured with different doses of genistein for different time periods, the cells were tested by MTT assay. Study on the ultrastructure of 3AO cells was performed by transmission electron microscope (TEM) after the administration of genistein. Apoptosis was detected by means of terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling (TUNEL) method. Apoptosis rate and cell cycle distribution of 3AO cells were measured by flow cytometry (FCM). The expression of estrogen receptor β protein was measured by immunocytochemical technique. RESULTS: After 3AO cells were treated with different concentrations of genistein, dose- and time-dependent growth inhibition was demonstrated. Inhibition percentage in cells exposed to 10 mg/L and 20 mg/L genistein for 72 h were, respectively, 54.24% and 65.99%. Also, genistein could block 3AO cells in the G2/M phase of cell cycle, and a typical sub-diploid apoptosis peak was demonstrated before G1/G2 phase. Moreover the apoptosis was time-dependent. The characteristic morphological changes of apoptosis in genistein-treated 3AO cells were observed by TEM. TUNEL staining revealed apoptosis-positive cells. Genistein could up-regulate the expression of ERβ. CONCLUSION: Genistein can dose- and time-dependently inhibit growth and induce apoptosis in ovarian carcinoma cell line 3AO the potential pathway of ERβ.