摘要
目的:研究人鼻咽癌细胞系CNE-2Z亚克隆株F1、S1放射后DNA修复相关基因DNA pol β和Ku80的表达,探讨CNE-2Z存在放射敏感性异质性的可能机理。方法:裸鼠体内移植瘤实验观察F1、S1放射后的体内增殖能力,采用Western blot、免疫细胞化学和免疫组织化学方法检测放射后F1和S1 DNA修复相关蛋白(DNA pol β、Ku80)的表达,Feulgen染色法和图像分析方法检测放射后F1、S1裸鼠体内移植瘤的DNA倍体及细胞周期分布情况。结果:未照射前F1细胞DNA pol β和Ku80的表达高于S1;放射后S1细胞DNA pol β及Ku80表达上调的时间较F1早,上调辐度大于F1。鼻咽癌细胞系CNE-2Z确实存在放射敏感性的异质性,放射后S1体内增殖能力大于F1,较多细胞处于有利于DNA修复的G2/M期(P<0.01)。放射后F1、S1裸鼠移植瘤细胞和组织中,DNA pol β和Ku80蛋白表达差异无统计学意义(P>0.05)。结论:本实验进一步证实了鼻咽癌细胞系CNE-2Z确实存在放射敏感性的异质性,F1、S1放射敏感性的差异与两株细胞的DNA修复相关基因(DNA pol β、Ku80)的表达差异所致的DNA SSB、DSB修复的速度和忠实性有关。
Objective： To investigate the expressions of DNA repair correlation genes,DNA pol β and Ku80,in subclone F1 and S1 of human nasopharyngeal carcinoma（NPC） cell line CNE-2Z and to discuss their possible mechanism of radiosensitivity heterogeneity.Methods： Nude mice transplantation experiment in vivo was used to observe reproductive activity of F1 and S1 xenografts after irradiation.The expression DNA repair correlation protein（DNA pol β and Ku80） in F1 and S1 after irradiation were detected by Western blot,cytochemistry and immunohistochemistry.Feulgen staining and image analysis were done to measure DNA ploidy and of cell cycle distribution of postradiation F1 and S1 xenografts.Results： The expressions of DNA pol β and Ku80 in S1 was slightly higher than that respectively in F1 without irradiation.After irradiation,the up-regulation of DNA pol β and Ku80 in S1 appeared earlier and maintained longer than that in F1.Radiosensitive heterogeneity really existed in NPC cell line CNE-2Z.S1 had a higher reproductive activity than F1 in vivo post-irradiation and more S1 cells were in G_2/M phase which profit DNA repair（P〈0.01）.There was no changes in expressions of DNA pol β and Ku80 in F1 and S1 transplanted tumor cells and tissue after irradiation（P〉0.05）.Conclusion： The present experiment further confirmed that radiosensitive heterogeneity really existed in NPC cell line CNE-2Z.Radiosensitive difference of F1 and S1 was correlated with DNA repair speed and fidelity in DNA SSB and DSB by different expression of DNA repair related genes（DNA pol β, Ku80）.
出处
《武汉大学学报（医学版）》
CAS
北大核心
2010年第4期462-467,共6页
Medical Journal of Wuhan University
