放射线对鼻咽癌细胞周期阻滞、凋亡和抑癌基因p57^kip2表达的影响

目的：研究放射线对鼻咽癌细胞（CNE）周期阻滞、凋亡和抑癌基因p57^kip2蛋白表达的影响。方法：运用流式细胞术检测放射线诱导的细胞周期阻滞、凋亡；运用免疫组织化学法和Westernblot法检测抑癌基因p57^kip2蛋白的表达。结果：照射后，CNE细胞G1期无明显阻滞，S期出现短暂堆积，G2／M期阻滞强度具剂量和时间依赖性，随照射剂量增加，其阻滞程度增强，阻滞时间延长，G2／M期阻滞在12、24h与照射剂量呈正相关（P〈0．01），随照射后时间延长而增强，峰值出现于12Gy24h；凋亡发生率与照射剂量和照射后时间均呈正相关（P〈0．01）。p57^kip2蛋白表达在照射后随照射剂量的增加和照射后时间的延长均呈现上调（P〈0．01）。结论：放射线对鼻咽癌细胞G2／M期阻滞、凋亡率和抑癌基因p57^kip2蛋白表达均有明显的增强作用。

Research on cell cycle arrest,apoptosis and the expression of tumor suppressor gene p57kip2 by radiation in nasopharyngeal carcinoma cell line in vitro

Objective:To investigate the effect of radiation on cell cycle arrest,apoptosis and the expression of antioncogene p57kip2 of nasopharyngeal carcinoma cells.Methods:Flow cytometry was used to detect the cell cycle arrest and apoptosis induced by radioation.Immunohistochemistry and western blot were used to detect the expression of antioncogene p57kip2 protein.Results:After radiation,cells at G1 phase had no obvious arrest.Cells in S phase showed transient delay.The retardation of cells at G2/M phase were dose and time dependent.The intensity time length of retardation increased along with irradiation dose.The peak appeared at 12Gy at hours.There was a positive correlation between retardation of cells at G2/M phase and irradiation dosage at 12 and 24 hours(P<0.01).The incidence of apoptosis showed a positive correlation with irradiation dosage and time length after irradiation(P<0.01).The expression of p57kip2 protein arose along with irradiation dose and time length after irradiation(P<0.01).Conclusion:Radiation has obviously positive effect on G2/M retardation,apoptosis incidence and the expression of antioncogene p57kip2 protein of nasopharyngeal carcinoma cells.