Objective:To investigate the regulatory effects of estradiol(E 2)

progesterone(P) and follicle-stimulating hormone(FSH) on proliferation and apoptosis in ovarian cancer cell line H0-8910 in vitro.Methods:Ovarian cancer cell line H0-8910 was cultured in vitro.Cell proliferation was measured by 3-(4

5-dimethylthiazol-z-yl)-2

5-dipheny tetrazolium blue(MTT) colorimetric assay.Cell cycle and apoptotic percentage were detected by flow cytometry;morphological changes of apoptotic cells were observed by electron microscopy

and apoptotic cells were quantitatively determined by terminal deoxynuclcotidyl transferase-mediated dUTP nick end labeling(Tunel).In addition

expression of intracellular bcl-2 protein was analysed by flow cytometric indirect immunofluorescent technique.Results:After incubation with 1×10 -12 mol/L E 2 or 10ng/ml FSH for 48 hours

cell proliferation increased significantly.E 2 and FSH increased the cells percentage in S phase and G 2/M phase of cell cycle respectively.Progesterone of 1×10 -7 ～1×10 -5 mol/L inhibited H0-8910 cell growth significantly in a dose-dependent manner after 24

48 and 72 hours.After treatment with progesterone

the enhanced G 0/G 1 arrest was accompanied with the enhanced apoptotic percentage

and apoptotic cells were found more than those in control group.By electron microscopy

there were many morphological characteristics of apoptosis.Analysis on expression of intracellular bcl-2 protein showed that progesterone could down-regulate bcl-2 protein.Conclusion:It is suggested that E 2 with low concentration and FSH with high concentration can stimulate the proliferation of epithelial ovarian cancer cell

while progesterone can inhibit cell growth and there is an accordant dose-response relationship.Its anticancer effect seems to be due to induction of apoptosis which may be a result of down-regulation of the anti-apoptotic protein bcl-2.