食管鳞癌组织中p16基因缺失及甲基化检测

Detection of p16 gene deletion and methylation in esophageal squamous cell carcinoma tissue

目的探讨食管癌组织中p16基因表达缺失的机制。方法采用PCR、DHPLC、MSP及免疫组化的方法,检测45例食管鳞癌组织及其相应的间变组织和正常食管上皮组织中p16基因的缺失、突变、甲基化状态及蛋白表达情况。结果正常食管上皮组织中p16蛋白均为正常表达(45/45,100%),间变和癌组织中异常表达率分别为84.4%(38/45)和91.1%(41/45),3者间异常表达率差异有统计学意义(χ2=20.03,P<0.001)。p16蛋白表达异常的41例癌组织中,纯合型甲基化发生率为80.48%(33/41),杂合缺失发生率58.53%(24/41),不缺失发生率41.46%(17/41),均高于p16蛋白表达正常的癌组织。结论该地区食管癌组织中p16基因主要通过纯合型甲基化失活。

Aim： To detect the p16 gene deletion and methylation in esophageal squamous cell carcinoma tissue. Methods： p16 expression, homozygous deletion and heterozygous loss of p16 at three exon loci, and the methylation status of the p16 promoter in 45 cases of SCC,its anaplastie tissue, and normal tissue were detected by PCR, DHPLC, MSP,and immunohistologieal methods. Results： Aberrant expression of p16 was 91.1% in cancer tissue and 84.4% in anaplastie tissue, and the difference was significant（ P 〈 0.05 ）. The rates of p16 heterozygus loss, biallelie methylation and nonloss in cancer tissue with aberrant expression of p16 protein were 58.53% （24/41） ,80.48% （33/41） , and 41.46% （ 17/41 ）, whieh were all higher than those of eaneer tissue with normal expression of p16 protein. Conclusion： Biallelie methylation of p16 explains the inactivation of p16 gene in esophageal squamous tissue.