Effect of Melatonin combined with cisplatin on proliferation and apoptosis of human esophageal carcinoma 109 cells

Objective:To explore the effects of melatonin combined with cisplatin on the proliferation and apoptosis of Eca109 cell and study the molecular mechanism.Methods:Eca109 cells were con-cultured with different concentrations of melatonin with or without cisplatin for 24 h.The inhibitory rate of Eca109 cells were examined using MTT assay, and the cell apoptosis was analyzed using flow cytometry with propidium iodide staining.Western blot for apoptosis-related protein Bcl-2 and Bax were used to analyze possible mechanisms of the synergistic anti-proliferation effect of melatonin in combination with cisplatin.Results:Different concentrations of melatonin combined with cisplatin showed an obviously enhanced inhibitory effect on colony formation of Eca109 cells.When melatonin combined with cisplatin, the cell apoptosis rate increased to 29%, significantly higher than that in cells with cisplatin treatment alone(9.7%)(P<0.01).The expression of Bcl-2 was high but Bax was low in Eca109 cells, after stimulating with melatonin and cisplatin, the expression of Bcl-2 decreased but expression of Bax increased.Conclusions:Melatonin can enhance the anti-proliferative effect of cisplatin on Eca109 cell and can enhance cisplatin-induced apoptosis.The possible mechanism may related to the downregulation of Bcl-2 and upregulation of Bax protein expression.