| AIM: To investigate the effect of inducing apoptosis and inhibiting proliferation on hepatoma cell lines by UDCA, and mechanisms of the effect. METHODS: UDCA effect of cell proliferation, apoptosis, cell cycle and the expression of bax, bcl-2 , c-myc, N-ras, P21 and P53 genes on two human hepatoma cell lines HepG2 and BEL7402, and normal human hepatic cell line L-02 in vitro was detected by MTT assay, flow cytometry, TUNEL assay, Wright-Giemsa staining, electron microscopy ,western blot,RT-PCR and immunocytochemistry. RESULTS: UDCA could strongly inhibit the proliferation of HepG2 and BEL7402 cell lines, and with the density of UDCA increasing, the effect of inhibiting proliferation would become more obvious. (r2=0.96, P<0.01; r2=0.97, P<0.01; 48h) . The IC50 to HepG2 and BEL7402 were 0.92 mmol.L-1, 0.86 mmol.L-1, respectively. The apoptosis rates (UDCA/1.0mmol.L-1) of HepG2 and BEL7402 were 42 ± 6% and 44 ± 4%, respectively, the rates were significantly higher than that of L-02 (P<0.01) , and UDCA could arrest cell cycle to S phase. Treated HepG2 with UDCA (0.8mmol.L-1), the expression of bcl-2 decreased from 24.3 ± 2.4% to 10.1 ±1.6%, the expression of Bax increased from 43 ±5% to 59 ± 3% (P<0.01); treated BEL7402, the expression of bcl-2 decreased from 21.6 ± 1.8% to 11.6 ± 2.1%, the expression of Bax increased from 44 ± 4% to 59 ± 3%(P<0.01) .The results of RT-PCR and western blot suggested that, UDCA can increase the expression of bax, P21 and P53, decrease the expression of bcl-2, c-myc, N-ras. UDCA had no obvious effect on L-02 cell line.CONCLUSIONS: UDCA Maybe selectively inhibit proliferation and induce apoptosis of HepG2 and BEL7402 cell lines by blocking cell cycle and regulating the expression of Bax/bcl-2 genes. |
