THE APOPTOTIC SUSCEPTIBILITY OF ESOPHAGEAL CELLS TO ARSENIC TRIOXIDE IS DETERMINED BY CELLULAR REACTIVE OXYGEN SPECIES LEVEL

Objective:To explore the relationship between the susceptibility to arsenic trioxide (As 2O 3) induced apoptosis of esophageal cells and the level of reactive oxygen species(ROS)of cells.Methods:Flow cytometry and electron microscopy were applied to identify apoptosis, and dihydrorhodamine123 and 2,7-dichlorodihydrofluorescein diacetate 2,7-dichlorodihydrofluorescein diacetate were used to display the ROS level of cells. As 2O 3 alone or in combination with 2,3-dimethoxy-1,4-naphthoquinone (DMNQ) were used to induce cell apoptosis. The results showed that EC/CUHK1 cells possessed higher level of ROS than EC/CUHK1(As-) cells.Results:DMNQ raised ROS levels of EC/CUHK1 and EC/CUHK1(As-) cells, sensitized EC/CUHK1(As-) cells to As 2O 3-induced apoptosis,and enhanced the efficacy of As 2O 3-induced apoptosis of EC/CUHK1 cells.Conclusion:Catalase reversed the effect of DMNQ on EC/CUHK1 and EC/CUHK1(As-) cells. It was concluded that the susceptibility of esophageal cells to arsenic trioxide-induced apoptosis is determined by ROS level in the cells.