Objective:To investigate the effects of all-trans retinoic acid (ATRA) on prolifetation and differentiation in ovarian cancer cell line COC1 in vitro.Methods:Human ovarian cancer cell line COC1 was cultured in medium containing ATRA in different concentrations in vitro.Cell proliferation inhibition was tested by MTT assay.The cell cycle was analyzed by flow cytometry(FCM).Morphological changes of cell differentiation were observed by light and transmission electron microscopy

and the expression of Ki-67 in cancer cells were measured with SP immunohistochemistry.In addition

CA 125 expression in the culture medium was measured by ELISA.Results:ATRA of 10 -7 ～10 -5 mol/L inhibited COC1 cell proliferation significantly in a dose-dependent and time-dependent manner.With the increase of ATRA concentrations

the number of cells in G 0/G 1 phase were elevated

the number of cells in S phase were obviously decreased.COC1 cells after treated by ATRA showed striking morphological characteristics of differentiation.The expression of Ki-67 was decreased in COC1 after ATRA treatment.ATRA could also suppress the expression of CA125 tumor marker in COC1 cells.Conclusion:ATRA can both inhibit proliferation and induce differentiation of human ovarian cancer cell line COC1.These results may provide an effective and novel approach for clinical treatment of human ovarian cancer.