食管癌组织中hMSH2基因启动子区甲基化检测

Detection of methylation of hMSH2 gene promoter region of esophageal cancer

目的检测食管癌组织中hMSH2基因启动子区甲基化状态,探讨与食管癌发生、发展的关系.方法 32例食管癌患者术前均未接受放疗、化疗等其他治疗,手术切除后30 min内,在癌组织及正常食管黏膜组织各取约1.0 cm×1.0 cm×1.0 cm大小的组织块标本,立即储存于-80℃冰箱中,冻存备提DNA.采用甲基化特异PCR法(MSP法)检测食管癌及正常食管黏膜组织中错配修复基因hMSH2启动子区甲基化的表达.结果 32例食管癌组织中,hMSH2启动子区甲基化发生率为34.4% (11/32),正常食管黏膜组织未发现甲基化,两组甲基化阳性率相比较,差异有统计学意义(P﹤0.01).高龄患者(≥70岁)癌组织中启动子区hMSH2甲基化发生率(85.7%)明显高于较低龄患者(﹤70岁,20.0%;P<0.05).病理组织学Ⅲ～Ⅳ级食管癌组织中,hMSH2启动子区甲基化发生率(70.0%)明显高于Ⅰ～Ⅱ级(18.2%,P<0.05).结论食管癌组织中,hMSH2基因启动子区甲基化与年龄和病理组织学分级可能有关.

Objective To detect methylation in promoter region of hMSH2 gene in esophageal cancer. Methods Specimens of cancer and normal tissues freshly removed from 32 cases of esophageal cancer patients without previous radiotherapy, chemotherapy or other treatment were preserved at - 80 ℃ within 30 min. Methylation specific PCR （MSP） was used to detect methylation of mismatch repair gene （MMR） hMSH2 in promoter region in esophageal cancer and normal esophageal tissues. Results The frequencies of methylation of hMSH2 gene in promoter region of cancer and normal esophageal tissues were 32.4% （11/32） and 0/30 （0%）, respectively, and significant difference was found between the two groups （P 〈0, 01 ）. The frequency of methylation in elder patients （ ≥70 years old） was significantly higher than that in younger patients （ 〈 70 years old） （P 〈 0, 05）. Methylation was less frequently found in grade Ⅰ-Ⅱ（18.2%） than in grade Ⅲ-Ⅳ（70,0%） （P〈0.05）. Conclusion Methylation of hMSH2 gene in promoter region is related to patients＇ age and histopathological grade of the esophageal cancer.