Experimental Study On Apoptosis Induced By All-trans-retinoic Acid In Human Androgen-independent Prostate Cancer Cell Line PC-3

Objective To investigate the effects of all-trans-retinoic acid(ATRA) on the proliferation and the expression of bcl-2 and bax in human androgen-independent prostate cancer cell line PC-3.Methods Human prostate cancercell line PC-3 was cultured in medium containing in different of ATRA concentrations. Cell proliferating inhibition was tested by MTT assay. The morphological change was analyzed by optical microscopy. The Annexin V/PI flow cytometry method was used to study the apoptosis induced by ATRA in PC-3 cells. Flow cytometry(FCM) and immunocytochemistry were used to analyze the expression of bcl-2 and bax in PC-3 cells. The protein expressions of bcl-2 and bax affected by ATRA were determined by Western blot.Results ATRA (10-6～10-4)mol/L inhibited prostate cancer cell line PC-3 proliferation in a dose-dependent and time-dependent manner(P<0.01).Typical morphological changes could be observed by using normal microscope after treatment with ATRA, including nuclear chromatin condensation, fragmentation, cell shrinkage and formation of apoptosis bodies. Apoptosis rates of PC-3 cells treated with 10-7,10-6,10-4 mol/L ATRA were (1.02±0.05)%,(26.51±1.08)%,(48.33±0.85)%.ATRA down-regulated the expression of bcl-2 and up-regulated the expression of bax in PC-3 cells. With the increase of ATRA concentration, the ratio of bcl-2 to bax decreased gradually(P<0.05).The expression level of bcl-2 decreased and the expression level of bax increased gradually with the increase of ATRA concentration.Conclusion ATRA can significantly inhibit the proliferation of human androgen-independent prostate cancer cell line PC-3.The apoptosis in PC-3 cells could be induced by ATRA in this study. The molecular mechanism of apoptosis may be...