鼻咽癌中p73基因启动子甲基化状态及转录表达的研究

Promoter Methylation and the mRNA Expression of p73 Gene in Human Nasopharyngeal Carcinoma

目的探讨鼻咽癌组织中p73基因启动子区甲基化状态及其对转录表达影响。方法运用甲基化特异性PCR和半定量反转录PCR法检测20例正常鼻咽上皮组织、54例鼻咽癌组织中p73基因启动子甲基化状态及其转录表达水平,分析鼻咽癌组织中p73基因甲基化与临床资料的关系以及p73基因甲基化对转录表达的影响。结果 54例鼻咽癌组织中p73基因启动子甲基化阳性率为38.89%(21/54),而正常鼻咽上皮组织中未检测到p73基因启动子甲基化;两组间p73基因启动子甲基化阳性率差异有统计学意义(P<0.01)。鼻咽癌组织中p73基因启动子甲基化与临床资料无关。21例甲基化鼻咽癌组织p73基因相对转录表达水平为1.04±0.64,33例非甲基化鼻咽癌组织p73基因相对转录表达水平为1.51±0.75,两者间有统计学差异(P<0.05),20例正常鼻咽上皮组织p73基因相对转录表达水平为1.12±0.31。结论鼻咽癌组织中p73基因甲基化与转录表达相关,是基因表达调节的一种重要方式,p73基因甲基化具有肿瘤特异性,p73基因甲基化与鼻咽癌发生发展有关。

Objective To investigate the promoter methylation status and mRNA expression of p73 genes in primary tumors from na- sopharyngeal carcinoma （NPC）. Methods The methylation - specific PCR （MSP） and semi - quantitative reverse transcription PCR （ RT - PCR） were used to detect methylatiou status and the mRNA expression level of p73 gene in 54 cases of NPC and 20 cases of normal nasopharyngeal epithelia tissues. The relationship between promoter methylation and clinical data,promoter methylation and mRNA expres- sion of the gene were analyzed. Results The methylation expression rates of p73 gene in NPC tissues were 38.89% （21/54） ,while there was no methylation in 20 cases of normal nasopharyngeal epithelia tissues. It was significantly statistical difference in NPC primary tumors compared with normal nasopharyngeal epithelia tissues（P 〈0.01 ）. There was no significant difference between promoter methylation and clinical data（ P 〉 0.05 ）. The mRNA relative expression level was 1.04 ± 0.64,1.51 ± 0.75 in 21 cases of methylated NPC tissues and 33 cases of unmethylated NPC tissues,respectively, p73 - methylated cases showed significantly lower level expression than unmethylated cases（ P 〈 0.05 ）. The mRNA relative expression level was 1.12 ± 0.31 in 20 cases of normal nasopharyngeal epithelia tissues. Conclusion The close correlation between p73 methylation and low mRNA expression suggests that methylation is an important pathway in the regula- tion of gene expression, p73 gene promoter methylation has high specificity in distinguishing cancers from normal tissues, p73 gene is connected with the tumorigenesis and development of NPC.