X射线对体外培养星形胶质细胞增殖的影响及机制研究

目的：观察X射线照射对培养星形胶质细胞（AS）增殖的影响,为X射线的广泛应用提供理论依据。方法：将体外培养80%汇合的AS,在AS无血清培养基继续培养48h后分为对照组和放疗组,对照组更换含10%FBS的DMEM-F12培养基,放疗组更换含10%FBS的DMEM-F12培养基,并同时给与X射线照射,利用western印迹分析各组PCNA、p53、cyclinE的表达。结果：X射线照射后能降低S期细胞比率,呈剂量依赖性,但并不增加AS的凋亡率。通过对AS无血清培养48h后,大部分细胞周期同步于G0期,对照组更换培养基后12h出现PCNA、cyclinE表达水平增高;放疗组p53表达水平较对照组显著增高,PCNA、cyclinE表达水平较对照组显著降低。结论：X射线照射可以通过调控细胞周期有效抑制AS的增生。

The Effect of X-ray Irradiation on Proliferation of in Vitro Cultured Astrocytes and the Mechanism

Objective：To investigate the effect of X-ray on proliferation of cultured astrocytes （AS） and the action mechanism. Methods.. The 80% confluent cultured AS were irradiated by different doses of X-ray, and effects of irradiation on cell cycle and apoptosis were analyzed by flow cytometry. The 80% confluent cultured AS were synchronized by serum deprivation for 48 h, then the cultured AS were randomly divided into 2 groups., control group （10% FBS） and irradiation group （10 % FBS＋irradiation）. Western bolt was used to detect the expression of PCNA, p53 and cyclin E. Results：X-ray irradiation could reduce the percentage of cells in S phase in a dose-dependent manner, but not increase the apoptosis rate of AS. After the culture was serum-starved for 24 h, almost confluent AS remained at GO phase. As a response to FBS, the percent of S phase cells and the expression levels of PCNA and cyclin E were increased in control group; In irradiation group, the percent of S phase cells was decreased dose-dependently. The expression of PCNA and cyclin E was also inhibited significantly, and the expression of p53 increased significantly in irradiation group as compared with control group. Conclusion： X-ray can effectively inhibit proliferation of AS by regulating cell cycle of AS.