放射线对体外培养鼻咽癌细胞细胞周期阻滞、凋亡和抑癌基因p57kip2表达的影响

目的研究放射线对鼻咽癌CNE细胞细胞周期阻滞、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检测抑癌基因p57^kip2蛋白的表达。结果CNE细胞经照射后，G1期无明显阻滞，S期出现短暂堆积，G2／M期阻滞程度具剂量和时间依赖性，G2／M期阻滞在12h与24h时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；细胞凋亡发生率与照射剂量和照射后时间均呈正相关（P〈0．01）。照射后p57^kip2蛋白表达随照射剂量增加和照射后时间延长而上调（均P〈0．01）。结论G2／M期阻滞、细胞凋亡率和p57^kip2蛋白均能反映及预测鼻咽癌细胞的放射敏感性。

Effect of Radioactive Rays on Cell Cycle Retardation, Apoptosis and the Expression of Antioncogene p57kip2 in Cultured Nasopharyngeal Carcinoma Cell Line in vitro

Objective To study cell cycle retardation, apoptosis and the expression of antioncogene p57 kip2 in nasopharyngeal carcinoma cells. Methods Radioactive rays-induced cell cycle retardation and apoptosis were detected by flow cytometry, and the expression of antioncogene p57 kip2 by immunohistochemistry.Results After irradiation, G_ 1 phase had no obvious retardation and S phase showed transient delay. There was a positive correlation between irradiation dosage and retardation strength in G_ 2 /M phase (P<0.01). Peak value appeared at 24 h after 12 Gy irradiation, then decreased. There was a positive correlation between apoptosis incidence and irradiation dosage or after-irradiation time extention (P<0.01). The expression of p57 kip2 protein was up-regulated along with time prolongation and increased dosage after irradiation (P<0.01).Conclusion G_ 2 /M phase arrest, apoptosis and the expression of p57 kip2 protein may reflect and predict the radiosensitivity in nasopharyngeal carcinoma cells.