鼻咽癌细胞株14—3—3σ启动子去甲基化与基因表达研究  

14-3-3 sigma Promoter de-methylation and gene expression in nasopharyngeal carcinoma cell lines

作　　者：谭双香[1] 易红[1] 汤参娥[1] 陈主初[1] 肖志强[1] 

机构地区：[1]中南大学湘雅医院卫生部肿瘤蛋白质组学重点实验室,长沙410078

出　　处：《国际肿瘤学杂志》2008年第4期312-315,共4页Journal of International Oncology

摘　　要：目的研究鼻咽癌细胞株14—3—3σ基因启动子甲基化状况及去甲基化处理对其表达的影响。方法用甲基化特异性聚合酶链反应（PCR）和逆转录PCR方法检测鼻咽癌细胞株CNEl、CNE2、5—8F、6-10B和非肿瘤人鼻咽上皮细胞NP69细胞14—3—3σ基因启动子甲基化状况和mRNA表达水平。用不同浓度5-杂氮-2’-脱氧胞苷（5-aza-2dC）处理鼻咽癌细胞株72h，检测处理组和对照组14—3—3σ基因启动子甲基化状况和mRNA表达水平，并用Western—blot检测14—3—3σ蛋白表达情况。结果NP69细胞14—3—3σ启动子未检测到甲基化，CNEl、CNE2、5-8F、6—10B细胞14—3—3σ基因启动子都存在甲基化，4株肿瘤细胞的14—3—3σ mRNA表达水平显著低于NP69细胞。5-aza-2dC处理能剂量依赖性地逆转鼻咽癌细胞14—3—3σ启动子的甲基化状态并上调其mRNA和蛋白质的表达水平，高分化细胞株（CNEl）对药物的敏感性高于低分化细胞株（CNE2、5-8F和6—10B）。结论启动子甲基化是导致鼻咽癌细胞株14—3—3σ mRNA和蛋白质表达降低的直接原因，14—3—3σ启动子去甲基化可能成为鼻咽癌治疗的新靶点。Objective To investigate the methylation status of 14-3-3σ promoter in nasopharyngeal carcinoma cell lines and the influence of de-methylation treatment on 14-3-3σ expression. Methods Methylation status of 14-3-3σ gene promoter and 14-3-3σ mRNA expression were detected by methylation specific PCR （MSP） and RT-PCR in nasopharyngeal carcinoma cell lines C NE1, C NE2,5-8F,6-10B and immortalized nonneoplastic human nasopharyngeal epithelial cell line, NP69. Four nasopharyngeal carcinoma cell lines were treated with 5-aza-2＇ -deoxycytidine（5-aza-2dC） in different concentration for 72 h, then 14-3-3σ promoter methylation status and mRNA expression were assessed, and western-blot was performed to detect the expression of 14-3-3σ protein. Results 14-3-3σ promoter methylation was detected by MSP in all of the four nasopharyn- geal carcinoma cell lines untreated by 5-aza-2dC whereas not in the treated ones or the immortalized human nasopharyngeal epithelial cell line, NP69. Accordingly, 14-3-3σ mRNA expression was significantly discounted in untreated nasopharyngeal carcinoma cell lines as compared with NP69. 5-aza-2dC treatment dose-depend- ently reversed 14-3-3σ promoter methylation status and consequently upregulated the expression of 14-3-3σ mRNA and protein in 4 nasopharyngeal carcinoma cell lines. High-differentiated CNE1 was more sensitive to 5- aza-2dC than lowly-differentiated CNE2, 5-8F and 6-10B. Conclusion Promoter methylation directly leads to decreased 14-3-3σ gene expression in nasopharyngeal carcinoma cell lines, and 14-3-3σ promoter de-methylation perhaps indicates a new target for nasopharyngeal carcinoma treatment.

关 键 词：鼻咽肿瘤 甲基化 启动区(遗传学) 脱氧胞苷 

分 类 号：R739.63[医药卫生—肿瘤]