Influences of Pretreating with 5-Aza-2'-dc on the Reactive Oxygen Level and the Expression of Protein Bcl-2 and Bax in Paraquat Sensitized V79 Cells / 昆明医科大学学报

ABSTRACT

Objective To study the reactive oxygen level and the expression of anti-apoptotic protein Bcl-2 and pro-apoptotic protein Bax after treatment of DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-Aza-2'-dc) and paraquat in V79 cells.Methods Cultured V79 cells were divided into 5-Aza-2'-dc treatment group (group A),paraquat treatment group (group B),5-Aza-2'-dc and paraquat treatment group (group C,V79 cells were pretreated with 5-Aza-2'-dc for 12h followed by exposure to paraquat for 12h) and control group (group D).Reactive oxygen level in V79 cells was measured by DCFH-DA flow cytometry and expression of Bcl-2 and Bax was detected by Western blot.Results Reactive oxygen levels and expression levels of Bcl-2 and Bax in V79 cells were significantly different (P＜0.05) in 5-Aza-2'-dc and paraquat treatment group (group C),compared with 5-Aza-2'-dc treatment group (group A),paraquat treatment group (group B) and control group (group D).Expression levels of Bcl-2 and the ratio of Bcl-2 and Bax were lower while reactive oxygen levels and expression levels of Bax were higher in group C than in groups A,B and D.Conclusion 5-Aza-2'-dc regulates DNA methylation by the imbalancing the reactive oxygen metabolism and apoptosis,thus up-regulating the toxic effect of paraquat on V79 cells.