Modulating effects of 9-nitrocamptothecin and its liposomes to induce apoptosis and inhibit cell cycle in HepG2 and L02 cell lines / 中华肝胆外科杂志

ABSTRACT

Objective To investigate the modulating effects and explore their mechanism of 9-nitrocamptothecin and its liposomes to induce apoptosis and inhibit cell cycle in HepG2 and L02 cell lines. Methods Cells were incubated with 9-nitrocamptothecin(9NC) or with 9-nitrocamptothecin liposomes for 24 h, 48 h and 72 h, then, the cell viability was measured via MTT assay; cell cycle and apoptosis was evaluated by flow cytometry after stained by PI and Annexin V-PE/7AAD. Additional, Western Blot was used to evaluate the expression of cell cycle and apoptosis related protein. Results Both cells viability were apparently inhibited by the 9-nitrocamptothecin and 9-nitrocamptothecin liposomes, the inhibitory effect showed a time-dependent and dose-dependent manner. Both S and G2/M phases arrest were observed after incubated with drugs. HepG2 cell was completely arrested in S phase when 9NC concentration over than 0. 1 μmol/L after incubation for 24 h, while more than 95% cells arrested in G2/M phase when 9NC concentration is 0. 1 μmol/L after incubation for 72 h. Apoptosis induction effect also showed a time-dependent and dose-dependent manner. Western Blot results showed the expression of Bax and Caspase-3 were upregulated while Cyclin A, Cdk2, Cyclin E and Bcl-2 were downregulated. More importantly, the compounds were more cytotoxic to the cancer cell lines than to the normal liver cell. Conclusions 9-nitrocamptothecin and 9-nitrocamptothecin liposomes can potently inhibit cell growth via regulation of cell cycle and induction of apoptosis, and this effect was preferentially in cancer cell. Inhibitory of 9-nitrocamptothecin liposomes was slightly better than the 9-nitrocamptothecin.