辐射对Jurkat细胞P21蛋白及ICR小鼠胸腺细胞p21基因表达的影响

Effects of ionizing radiation on expression of P21 protein in Jurkat cell line and p21 gene inthymocytes and splenocytes of mice

目的探讨电离辐射对Jurkat细胞P21蛋白和ICR小鼠胸腺细胞p21基因表达的影响。方法采用流式细胞术（FCM），检测0、0．5、1．0、2．0、4．0及6.0GyX射线照射后Jurkat细胞中P21蛋白表达的变化。采用实时定量PCR技术，分别检测0、0．5、1．0、2．0、4．0及6．0GyX射线照射后4和24h小鼠胸腺及脾细胞中p21基因表达的变化。结果不同剂量x射线照射后12和24h，Jurkat细胞中P21蛋白表达在0.5-4.0Gy范围内均随剂量的增大而升高（t=-24.23～-3.96，P〈0.05），6Gy时均出现表达下降（t=-11.19、-14.50，P〈0.05）；与假照射组相比，在0～6.0Gy照射后4和24h，小鼠胸腺及脾细胞中p21基因的相对表达量均随剂量增大逐渐增加（t=-29.96～8.80，P〈0.05）；并于6.0Gy时达最高（t=-11.84-3.42，P〈0.05），仅胸腺细胞1Gy照射后4h除外（t=-3.42，P〉0.05）。结论x射线能诱导P21蛋白及基因表达增加，并在一定剂量范围内存在良好的剂量-效应关系。

Objective To investigate the effects of ionizing radiation on the expression of P21 protein in Jurkat cell line and p21 gene in thymoeytes and splenocytes of mice. Methods Flow eytometry （FCM） was used to analyze the expression of P21 protein in Jurkat cells at 12 and 24 h after irradiation to 0, 0.5, 1.0, 2.0, 4.0, and 6.0 Gy. Real-time PCR was used to detect the expression of p21 gene in thymocytes and splenoeytes of mice at 4 and 24 h after irradiation to 0, 0.5, 1.0, 2. 0, 4.0, and 6. 0 Gy. Multi-staining was used to analyze the micronueleus rates of Rct in bone marrow. Results The expressions of P21 protein were increased in a dose-dependent manner during 0.5 -4.0 Gy（ t=-24.23-3.96, P〈0.05 ） , but decreased at 6.0 Gy at 12 and 24 h post-irradiation （ t=-11.19, -14.50, P〈0.05）. The expressions of p21 gene in both thymocytes and splenocytes of mice were increased in dose-dependent manner in the range of 0 - 6. 0 Gy（ including 6.0 Gy） （t =-29.96-8.80, P 〈 0.05 ） , and reached to the peak at 6.0 Gy at 4 and 24 h post-irradiation（t = - 11.84 - -3.42, P 〈0.05）, except thymocytes at 4 h and 1.0 Gy post-irradiation （ t =-3.42, P 〉 0.05 ）. Conclusions The expressions of P21 protein and p21 gene could be increased by X-ray irradiation, which shows good dose- deoendent manners in certain range of dose.