基因hMSH2、hMLH1与p53突变型在散发性大肠癌患者的表达

目的:探讨错配修复基因hMSH2、hMLH1与p53突变型在散发性大肠癌发生中的作用。方法:用聚合酶链反应和单链DNA多态性分析(PCR-SSCP)对45例散发性大肠癌患者肿瘤组织及正常组织基因hMSH2、hMLH1、p53进行检测。结果:45例散发性大肠癌患者中,发生hMSH2、hMLH1、p53基因突变分别为2、6、22例,分别占4.44%、13.33%和48.89%。hMLH1、hMSH2基因在突变型p53患者中的突变率为27.27%明显高于在p53未发生突变的患者中的突变率8.69%(P<0.05)。结论:一定比例的散发性大肠癌患者中存在MMR基因缺陷,其中hMLH1所起的作用大于hMSH2,散发性大肠癌中MMR基因突变与p53突变密切相关。

Expression of hMSH2, hMLH1 and p53 in the sporadic colorectal carcinoma

Objective: To investigate the role of mutated mismatch repair gene hMLH1 and hMSH2 in the carcinogenesis of sporadic colorectal carcinoma (SCC). Methods: hMSH2,hMLH1 and p53 gene in normal and tumor tissue in 45 SCC specimens were detected by polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP) EB staining. Results: The mutation rate of hMLH1,hMSH2 and p53 expression was 4.44%(2/45),13.33%(6/45)and 48.89%(22/45)in SCC respectively. The frequency of mutated mmr (hMLH1 and hMSH2) in mutated p53 patients was 27.27%,while it was 8.69% in un-mutated p53 patients (P<0.05). Conclusion: There is a subset of SCC displaying MMR gene defect,in which the hMLH1 gene plays more important role in SCC than hMSH2 does. Furthermore,there is a closely relationship between mutation of MMR gene and mutation of p53 gene.