激光捕获显微切割技术研究胃癌hMSH2基因突变与蛋白表达的关系

The study of expression and mutation of gene hMSH2 and correlation of them in gastric carcinoma

目的通过对胃癌组织中错配修复基因hMSH2基因蛋白表达、hMSH2基因突变关系的研究,探讨错配修复基因hMSH2基因与胃癌临床病理特征的关系和意义及其导致胃癌的可能机制。方法 (1)应用免疫组织化学SP法检测45例胃癌组织hMSH2基因蛋白表达情况。(2)激光捕获显微切割设备直接获取胃癌细胞。(3)应用聚合酶链反应-单链构象多态性分析(PCR-SSCP)-银染技术,分别检测45例胃癌组织中5个外显子hMSH2基因突变的情况。结果 (1)45例胃癌组织中hMSH2基因蛋白表达阴性9例(20.00%),阳性36例(80.00%)。hMSH2基因蛋白表达阴性率与患者的年龄、性别、发生部位、有无淋巴结转移、组织学类型、分化程度及进展程度均无相关性(P>0.05)。(2)45例胃癌组织中,hMSH2基因突变共4例(8.89%)。hM-SH2基因突变率与胃癌患者的年龄、性别、发生部位、有无淋巴结转移、组织学类型、分化程度及进展程度均无相关性(P>0.05)。(3)hMSH2基因蛋白表达阴性的胃癌组有4例hMSH2基因突变(44.44%),hMSH2基因蛋白表达阳性的胃癌组见hMSH2基因突变0例(0.00%),hMSH2基因蛋白表达阴性胃癌组hMSH2基因突变率与hMSH2基因蛋白表达阳性组比较,差异有统计学意义(P<0.01)。结论 hMSH2基因突变可能参与胃癌的发生,且可能是引起胃癌中该蛋白表达缺失原因之一。

Objective To study the expression and mutation of mismatch repair gene hMSH2 and correlation of them in gastric carcinoma,to evaluate their clinicapathological characteristics and the possible mechanism of carcinogenesis caused by hMSH2.Methods（1） 45 cases of gastric carcinoma were examed.The expression of hMSH2 protein was examed by immunohistochemistry.（2）The cells of gastric carcinoma were got through laser capture microdissection.（3）45 cases of gastric carcinomas were studied respectively with five exons of hMSH2 gene emutation by using polymerase chain reaction（PCR）,single strand conformation polymorphism（SSCP） and silver-staining.Results（1） In 45 cases of gastric carcinoma,the negative expression rate of hMSH2 protein was 20.00% while the positive expression rate was 80.00%.No significant association was observed between hMSH2 protein expression and patient′s age,gender,part,lymph node metastases,histological type,differentiation and stage of pathology（P〈0.05）.（2） In 45 cases of gastric carcinoma,five exons mutation rate of hMSH2 gene was 8.89% and not significantly associated with gender,age,part,lymph node metastases and histologic type,differentiated grade and stage of clinical pathology（P〈0.05）.（3）The hMSH2 gene mutation rates of the gastric carcinoma with the hMSH2 protein negative expression and with the hMSH2 protein positive expression were 44.44% and 0.00% respectively.There were significant difference between them（P〈0.01）.Conclusion hMSH2 gene mutation may be involved into the pathogenesis of gastric carcinoma and cause depressed expression of hMSH2 protein.