食管鳞癌组织中hMLH1基因微卫星变异检测

目的:探讨食管鳞癌及不典型增生组织中hMLH1基因微卫星变异。方法:采用PCR-变性聚丙烯酰胺凝胶电泳-银染技术,对40例食管鳞癌、40例正常及26例不典型增生组织中hMLH1基因所在区域的3个微卫星位点D3S1561、D3S1289及D3S1448进行检测,分析其微卫星不稳定(MSI)及杂合性缺失(LOH)状况。结果:在不典型增生组织中三个位点的MSI总阳性率为65.0%,高于在癌组织的30.0％(P<0.05);前者的LOH总阳性率为7.6％,与后者的7.5％比较差异无统计学意义(P>0.05)。癌组织的MSI及LOH与不典型增生组织的MSI及LOH的r分别为0.623和1(P均<0.05)。结论:错配修复缺陷参与了食管鳞癌的发生过程,且是早期分子事件;在食管鳞癌发生发展过程中,hMLH1基因的LOH并非一个常见和重要的事件。

Microsatellite alteration of hMLH1 gene in squamous cell carcinoma and dysplasia of esophagus

Aim : To study the stability status of hMLH1 gene in esophagus squamous cell carcinoma and dysplasia tissue, and to analyze the relationship between it and oncogenesis, progression of esophagus squamous cell carcinoma. Methods : 40 esophagus squamous cell carcinoma samples, 40 normal tissue samples and 26 dysplasia tissue samples were collected. By polymerase chain reaction ( PCR)-denaturing polyacrylamide gel electrophoresis-silver staining technique, 3 mi-crosatellite loci (D3S1561 , D3S1298, D3S1448) in the site where hMLHl gene located were checked, to analyze the status of microsatellite instability (MSI) and loss of heterozygosity (LOH) in dysplasia and tumor tissue. Results: In dysplasia tissue, the total positive rate of MSI in three loci was 65. 0% , and was higher than the homologue (30. 0% ) in tumor tissue (P<0.05) ;the total positive rate of LOH was 7.6% in former, showing no significant difference compared to the homologue in latter. The correlation was found between MSI and LOH in former and those in latter, respectively ( P < 0.05). Conclusion:Defecency of mismatch repair is involved in carcinogenesis of esophageal squamous cell carcinoma, and occurs in the early stage. In the carcinogenesis and progression of esophageal squamous cell carcinoma, LOH of hMLHl gene is not a frequent and important event.