基因甲基化导致鼻咽癌组织14-3-3σ表达下调  

Hypermethylation Leads to Down-regulated 14-3-3 Sigma Expression in Nasopharyngeal Carcinoma Tissues

作　　者：谭双香[1,2] 李君[1] 易红[1] 汤参娥[1] 程爱兰[1] 陈主初[1] 李建玲[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410008 [2]湖南省老年医院-湖南省老年医学研究所,长沙410016

出　　处：《生物化学与生物物理进展》2009年第6期743-749,共7页Progress In Biochemistry and Biophysics

基　　金：教育部跨世纪优秀人才培养计划基金(教育部科技函[2002]48);湖南省科技重点科研项目(06SK2004);芙蓉学者特聘教授科学研究基金(湘教通[2007]362号)资助项目~~

摘　　要：为探讨14-3-3σ基因甲基化在鼻咽癌发病中的作用,以75例鼻咽癌活检组织和25例正常鼻咽黏膜活检组织作为研究对象,采用甲基化特异性聚合酶链式反应(MSP)检测14-3-3σ基因甲基化状态,逆转录聚合酶链式反应(RT-PCR)检测14-3-3σmRNA表达,免疫组织化学染色检测14-3-3σ蛋白质表达.结果发现,鼻咽癌组织14-3-3σ基因完全甲基化、不完全甲基化和未甲基化的例数分别为4例、59例和12例,正常鼻咽黏膜组织不完全甲基化和未甲基化的例数分别为7例和18例,鼻咽癌14-3-3σ基因甲基化频率显著高于正常鼻咽黏膜组织(84%vs28%,χ2=28,P<0.05).RT-PCR和免疫组织化学染色结果显示:14-3-3σ基因完全甲基化的组织样本无14-3-3σ表达,不完全甲基化的组织样本14-3-3σ表达显著降低,14-3-3σ基因甲基化与鼻咽癌淋巴结转移及鼻咽癌临床分期正相关.研究结果表明,鼻咽癌组织14-3-3σ基因存在高频甲基化,14-3-3σ基因甲基化导致14-3-3σ表达降低或缺失,14-3-3σ表达水平与鼻咽癌淋巴结转移及其临床分期相关.In order to explore the role of 14-3-3σ gene methylation in nasopharyngeal carcinoma pathogenesis, biopsy specimens of 75 nasopharyngeal carcinoma tissues and 25 normal nasopharyngeal mucosal tissues were harvested for research. Then, methylation specific PCR （MSP） experiment was introduced to reveal 14-3-3σ gene methylation status of tissues, and reverse transcriptional PCR （RT-PCR） assay was employed to quantify the expression of 14-3-3σ mRNA, further more, immunohistochemical staining was undertaken to assess the 14-3-3σ protein expression level. The MSP experiment results indicate 14-3-3σ gene methylation status in nasopharyngeal carcinoma tissues was 4 exhaustive methylation, 59 partial methylation and 12 unmethylation, while in normal nasopharyngeal mucosal tissues was 7 partial methylation and 18 unmethylation. The frequency of 14-3-3σ methylation in nasopharyngeal carcinoma tissues was significantly higher than that in normal nasopharyngeal mucosal tissues （84% vs 28%, x^2=28; P 〈 0.05）. The results of RT-PCR and immunohistochemical staining discovered that 14-3-3σ gene exhaustive methylation leads to absent 14-3-3σ mRNA as well as protein expression in nasopharyngeal carcinoma tissues and normal nasopharyngeal mucosal tissues. Tissues characterized with partial methylation 14-3-3σ gene represented remarkable down-regulated 14-3-3σ mRNA and protein expression level when compared with tissues characterized with unmethylation 14-3-3σ gene. Graded correlation analysis discovered that 14-3-3σ gene hypermethylation status is positively correlated with NPC lymphoid node metastasis and NPC clinical staging. The research demonstrated that 14-3-3σ gene was frequently hypermethylated in nasopharyngeal carcinoma tissues and leads to decreased or depleted gene expression, 14-3-3σ expression level was correlated to nasopharyngeal carcinoma lymphoid node metastasis and NPC clinical staging.

关 键 词：鼻咽肿瘤 表观遗传学 基因表达 甲基化 14-3-3σ 

分 类 号：Q5[生物学—生物化学] R73[医药卫生—肿瘤]