| Objective:To investigate the effects of Harmine on inhibition of proliferation and on apoptosis, and the underlying mechanisms in a human hepatoblastoma HepG2.Methods:The proliferation of HepG2 cells was determined by Cell Counting Kit-8 (CCK-8) assay and cloning formation test. The cellular morphology of HepG2 cells was observed by Hoechest 33258 staining using fluorescence microscopy. Annexin V-PI was performed to analyze cell apoptosis and PI was performed to analyze cell cycle contribution. Western blotting was used to detect the expression of apoptosis-regulated gene Bcl-2, Bax, Bcl-xl, Mcl-1, Caspase-3, Caspase-9. Mitochondrial transmembrane potential (Δψm) was determined by Mitochondrial membrane potential assay kit with JC-1.Results:Harmine inhibited the proliferation of HepG2 cell line in a dose dependent manner. Hoechest 33258 staining revealed that the nuclear fragmentation and chromosomal condensed, cells shrank and attachment loss appeared in the HepG2 treated with Harmine. The percentage of the sub/G1 fraction was increased in a concentration dependent manner, indicative of apoptotic cell death. PI staining showed that Harmine could change the cell cycle distribution of HepG2, decreased the proportion of cells in G0-G1 phase and increased the proportion of S phase cells and G2-M phase cells. Harmine induced apoptosis in a concentration dependent manner, with occurrence rates of apoptotic cells of 20.00%, 32.70% and 64.90%, respectively. JC-1 revealed a decrease in mitochondrial membrane potential. Apoptosis of HepG2 cells was associated with Caspase-3 and Caspase-9 activation, down-regulation of Bcl-2, Mcl-1, Bcl-xl, and no-change of Bax.Conclusion:Harmine exhibited an anti-proliferative effect in HepG2 cells by inducing apoptosis. Mitochondrial signal pathways involved in the apoptosis of HepG2. The cancer-specific selectivity shown in this study suggest that Harmine could be a promising novel drug for human hepatocellular carcinoma. |
PDF Full Text Request