整体照射后胸腺细胞和脾细胞p16基因转录和蛋白表达的变化

Changes in p16 mRNA level and protein expression in thymocytes and splenocytes after whole body irradiation

研究X射线全身照射对小鼠胸腺细胞和脾细胞p16基因转录及蛋白表达的影响。采用Northern blot检测p16基因转录水平的变化;采用流式细胞术检测蛋白表达的变化。时程结果表明,2.0Gy照射后4-24h,胸腺细胞p16mRNA水平明显增高,8-48h P16蛋白表达显著增高(p<0.05-p<0.01);照射后4-8h脾细胞p16mRNA水平明显增高,24h P16蛋白表达显著增高(p<0.05)。量效结果表明,0.5-6.0Gy照射后,胸腺细胞p16mRNA水平呈剂量依赖性增高,P16蛋白表达在1.0-4.0Gy组明显高于假照射组(p<0.05-p<0.01);脾细胞p16mRNA水平亦增高,但增幅远低于胸腺细胞,P16蛋白表达在1.0-4.0Gy组明显高于假照射组(p<0.05-p<0.01)。X射线全身照射可诱导胸腺细胞和脾细胞p16基因转录及蛋白表达增高。p16表达参与整体照射诱导细胞G1期阻滞的分子调控。

To investigate the effect of ionizing radiation on p16 gene transcription and protein expression of thymocytes and splenocytes in mice. Northern blot was applied to determine p16mRNA level. Flowcytometry (FCM) was employed to measure p16 protein expression. The time-course experiments showed that p16mRNA level was markedly increased at4-24h in thymocytes and at4-8h in splenocytes, and p16 protein expression increased significantly at 8-48h in thymocytes (p<0.05-p<0.01) at 24h in splenocytes (p<0.05) after 2.0Gy whole body irradiation with X-rays. The dose-effect experiments showed that p16mKNA level of thymocytes and splenocytes increased with increasing doses and the p16 protein expression increased significantly, too, when the dose increased from 1.0 to 4.0Gy for both thymocytes and splenocytes (p <0.05-p<0.01). p16 gene transcription and protein expression could be induced by X-rays irradiation, and tendency of the increase varied with the dose and cell type. The results suggested that p16 expression played a critical role in G1 arrest induced by ionizing radiations