NOX家族在X射线诱导PC-3细胞损伤中的作用

目的:研究NOX家族在X射线诱导人雄激素非依赖性前列腺癌PC-3细胞损伤中的作用,寻找放疗增敏的潜在靶点。方法:采用噻唑蓝(MTT)比色法检测0、1、2、4和12 Gy X射线照射后24、48和96 h PC-3细胞存活率;采用DCFH-DA法检测0、1和4 Gy X射线照射后15、30、60和120 min时PC-3细胞中ROS的生成量;采用Western blot方法检测0、1和4 Gy X射线照射后PC-3细胞中NOX1～NOX5 5个亚型蛋白的表达情况。结果:1、2、4和12 Gy X射线照射PC-3细胞后96 h,与未照射组比较,PC-3细胞的存活率明显下降(P0.05)。1和4 Gy X射线照射PC-3细胞60 min后,细胞内ROS水平最高,NOX抑制剂DPI及抗氧化剂N-乙酰半胱氨酸(NAC)预处理可以减少ROS的生成。1和4 Gy X射线照射后PC-3细胞中NOX1、NOX2和NOX5蛋白表达显著增加。结论:X射线诱导NOX1、NOX2和NOX5蛋白过表达,细胞内产生过量的ROS是X射线诱导PC-3细胞损伤的机制之一。

Role of NOX family in PC-3 cell damage induced by X-ray irradiation

OBJECTIVE：To study the role of NOX（NADPH oxidase） in X-ray-induced damage of human androgen-independent prostate cancer PC-3 cells damage,search for potential targets for radiation sensitization. METHODS：The viability of human androgen-independent prostate cancer PC-3 cells induced by 0,1,2,4 and 12 Gy of X rays after 24,48 and 96 h was detected by the MTT assay.The level of ROS after X-ray irradiation for 15,30,60 and 120 min,and the expression of NOX 1-5 protein in PC-3 cells induced by 0,1 and 4 Gy of X rays was analyzed by using DCFH-DA as a probe and by Western blot,respectively.RESULTS：Compared with nonirradiated, the viability of human prostate cancer PC-3 cells induced by 1,2,4 and 12 Gy of X rays was significantly decreased（P0.05）.The level of ROS reached a maximum at 60 min after 1 and 4 Gy of X-ray irradiation.NOX inhibitor DPI and antioxidant NAC pretreatment could reduce the generation of ROS.Western blotting showed the expressions of N0X1,NOX2 and NOX5 were increased after irradiation.CONCLUSION：X-ray-induced the homologs NOX1,NOX2 and NOX5 of the catalytic subunit gp91~（phox） of NADPH oxidase over-expression,resulting in excessive intracellular ROS which is a new mechanism of X-ray-induced damage of prostate cancer cells.