Synergistic Inhibitory Effect of 1,25-Dihydroxy Vitamin D_3 and All-trans Retinoic Acid on Growth of Human Ovarian Cancer Cell Line HO8910

To investigate the effects of 1,25-dihydroxy vitamin D3 [1,25(OH)2D3]and all-trans retinoic acid (ATRA)on growth and cell cycle and apoptosis of human ovarian cancer cells HO8910,and the expression of vitamin D receptor and the retinoic acid receptor α mRNA ,then explore the molecular mechanism, HO8910 human ovarian cancer cell line were cultured in vit ro and treaed with1,25(OH)2D3,ATRA,or the combination of both chemicals,cell proliferation was evaluated by MTT assay.Cell cycle and apoptosis were determined by flow cytometry (FCM).The expression of VDR and RARα mRNA were determined by reverse transcription-polymerase chain reaction (RT-PCR). It is resulted that 1,25(OH)2D3 and ATRA used alone or incombination, inhibited the growth of HO8910 cells in a time dependent manner (P0.05).FCM analysis indicated that 1,25(OH)2D3 and ATRA used alone or incombination could change cell cycle of HO8910 cells(P0.05),increased the rates of G1,induced apoptosis(P0.05). They could up-regulation of VDR and RARα(P0.05),then inhibit proliferation of HO8910 cells. All of the effects were more obvious in the combination group than in 1,25(OH)2D3or ATRA groups(P0.05). It is conclused that 1,25(OH)2D3 and ATRA could inhibit cell growth ,change the cell cycle and induced G1 phase arrest of HO8910 cells,induce apoptosis,they could up-regulation of VDR or RARα,then inhibit proliferation of HO8910 cells.Furthermore,the combination of 1,25(OH)2D3 and ATRA could exert synergistic inhibitory efect on the growth of HO8910 cells.