ABSTRACT
AIM:TostudythechangeofradiosensitivityofU251cellsaftertreatedwithsodiumdichloroacetate ( DCA) and further to explore the possible mechanism .METHODS: The U251 cells were divided into 4 groups: control group, DCA group, X-ray irradiation without DCA pretreatment ( IR) group and X-ray irradiation with DCA pretreatment ( DIR) group.MTT assay was applied to determine the cell viability .The intracellular reactive oxygen species ( ROS) were detected by DHE fluorescence .The expression level of Bcl-2 was assessed by Western blot .The percentage of apoptosis of cells was determined by flow cytometry .RESULTS:No difference between control group and DCA group in cell viability (P>0.05) was observed.However, the cell viability of both IR group and DIR group was markedly reduced compared with control group ( P<0.05).Furthermore, the viability of DIR group was significantly decreased compared with IR group ( P<0.05 ) .The percentage of ROS positive cells was obviously increased in DIR group compared with IR group (P<0.05).The expression level of Bcl-2 was sharply decreased in DIR group (P<0.05) and the percentage of apoptosis of cells was significantly elevated ( P<0.05) in DIR group compared with IR group .CONCLUSION:The better antitu-mor effect was obtained by improving the radiosensitivity through pretreating the cells with DCA , and the possible mecha-nism was down-regulation of the Bcl-2 expression by developing the intracellular ROS .