Abstract: Objective To investigate the effects of manganese ion (Mn²⁺) on the proliferation and apoptosis of liver cancer cells. Methods Hepatoma Huh7 and HepG2.2.15 cells were treated with different concentrations (1, 4, 16, 64, 256  and 1 024 μmol/L, respectively) of Mn²⁺ solutions, and the corresponding cells without Mn²⁺ solution treatment were used as the control group. The cell proliferation was detected by CCK⁃8 assay and colony formation assay, and the apoptosis rate was detected by flow cytometry. Results The results of CCK⁃8 assay showed that compared with the control group, the cell proliferation activity of Huh7 cells was decreased under the treatment of all the conentrations of Mn²⁺ solution except the one of 1 μmol/L (all P<0.05); the proliferation activity of HepG2.2.15 cells was significantly decreased under the treatment of all the conentrations of  Mn²⁺ solutions except those of 1 μmol/L and 4 μmol/L (all P<0.0001), and with the increase of Mn²⁺ concentration, the inhibition of cell proliferation in both groups was more and more significant. The results of colony formation assay showed that the colonies number of Huh7 cells was decreased under the treatment of all the Mn²⁺ solution except those of 1 μmol/L and 4 μmol/L (all P<0.01); the colonies number of HepG2.2.15 cells was decreased under the treatment of all the Mn²⁺ solution except the one of 1 μmol/L (all P<0.0001), and with the increase of Mn²⁺ concentration, the colonies number of cell decreased significantly. The results of apoptosis experiment showed that the apoptosis rates of Huh7 cells and HepG2.2.15 cells treated with 64 μmol/L and 1 024 μmol/L Mn²⁺ solution (respectively) were significantly different (all P<0.01), and the apoptosis rates increased with the increase of Mn²⁺ concentration. Conclusion Mn²⁺ can inhibit the proliferation and colony formation of liver cancer cells and induce apoptosis.

Key words: Liver cancer')">Liver cancer, Manganese ion, Cell proliferation, Cell apoptosis