中文摘要：

目的：探讨CDKN1A基因的表达与鼻咽癌放射敏感性的关系。方法构建慢病毒表达载体LV-CDKN1A-RNAi并转染鼻咽癌放射抗拒性CNE-2R细胞，设转染LV-CDKN1A-RNAi慢病毒的CNE-2R细胞为实验组，转染阴性对照慢病毒的CNE-2R细胞为阴性对照组，未转染的CNE-2R细胞为空白对照组。用CCK-8法、细胞克隆形成实验及流式细胞术分别检测各组细胞增殖、放射敏感性及细胞周期的变化。结果成功构建了CDKN1A基因沉默的CNE-2R细胞，CCK-8法检测显示实验组CNE-2R细胞在照射6 Gy后生长受到抑制，且随时间延长其抑制作用更为明显。细胞克隆形成实验显示实验组CNE-2R细胞放射敏感性增强（放射增敏比为SER=1.24）。流式细胞术检测显示实验组与对照组细胞相比， G0/G1期和G2/M期细胞分布在X射线照射6 Gy前后明显改变（P约0.05）。结论 CDKN1A基因沉默能增强鼻咽癌放射抗拒性CNE-2R细胞的放射敏感性，CDKN1A基因的表达可能与鼻咽癌放射敏感性相关，有望成为鼻咽癌治疗的新靶点。

英文摘要：

Objective To investigate the relationship between the CDKN1A gene expression and the change of radiosensitivity of human nasopharyngeal carcinoma. Methods Lentiviralvector-mediated RNA interference（LV-CDKN1A-RNAi）targeting was constructed and transfected it to CNE-2R cells.CNE-2R cells transfected with LV-CDKN1A-RNAi were taken as experimental group,those transfectedwith control virus and without any treatment were taken as control group and blank group.The proliferation inhibitory rate was measured by CCK-8 assay.Colony formation assay was performed to determine the radiosensitizing effect.Cell cycle distribution was analyzed by flow cytometry. Results The stably silenced expression of CDKN1A CNE-2R cell line was established.CCK-8 assay showed that the growth of CNE-2R cell of the experimental group was inhibited after 6 Gy irradiating,which was closely related to growth time.The results of colony formation assay showed that the radiosensitivity of CNE-2R cell of the experimental group was more＆amp;nbsp;enhance（SER=1.24）than the other groups.Comparing with control group,cell cycle distribution showed that the cell distribution of G0/G1 and G2/M cycle in the experiment group was significantly changed before and after 6 Gy irradiating. Conclusions Silencing gene CDKN1A may enhance the radiosensitivity of CNE-2R cells of human nasopharyngeal carcinoma,which maybe used as a thera-peutic target for nasopharyngeal carcinoma.