同源不同辐射抗拒 NPC 细胞间总甲基化水平及基因甲基化表达差异的探讨

摘要

目的：比较同源不同辐射抗拒能力的鼻咽癌细胞CNE2R／CNE2间总甲基化水平及其区域的差异。方法：采用赵存友博士改良的基于甲基化敏感酶全基因组甲基化法检测CNE2R／CNE2细胞全基因组甲基化水平；同时采用MeDIP-Seq测序法对CNE2R／CNE2细胞进行测序，分析比较DNA甲基化区域（主要包括6个基因功能元件即CDS、intron、downstream2k、upstream2k、3’UTR及5’UTR）的差异。结果： CNE2R细胞全基因组甲基化水平比CNE2细胞低约30％；在CNE2R和CNE2细胞中，虽然分布在6个基因功能元件上的峰值个数和峰值在各基因元件上的覆盖度均无明显差异，但2种细胞的6个基因功能元件上基因甲基化存在差异。结论：同源不同辐射抗拒能力的鼻咽癌细胞间总甲基化水平及基因甲基化存在差异，推测DNA甲基化的差异可能与鼻咽癌辐射抗拒相关。%[ ABSTRACT] AIM:To compare the differences of the genome-wide methylation levels and methylated regions be-tween nasopharyngeal carcinoma ( NPC) cells in the same genetic background but different radiation resistance ( CNE-2 cells and CNE-2R cells).METHODS:Using the method which was developed by Doctor Zhao Cun-you, based on using methyl-sensitive restriction enzyme to measure the genome-wide methylation levels.In addition, MeDIP-Seq was used to analyze the methylated regions in 6 gene functional elements, including the upstream 2k sequence, 5’ UTR, coding se-quence, intron, 3’UTR and downstream 2k sequence, between CNE-2 cells and CNE-2R cells.RESULTS:The genome-wide methylation level was approximately 30%lower in CNE-2R cells than that in CNE-2 cells.No obvious difference on the amount of genes and the coverage of the peak in the 6 gene functional elements was observed.However, the methylation pattern of plentiful genes had altered in the gene function elements.CONCLUSION:The genome-wide methylation levels and methylated regions between NPC cells in the same genetic background but different radiation resistance were quite dif-ferent, indicating that the DNA methylation may be associated with NPC radioresistance.