大肠癌发生中突变型P53与hMLH1表达的关系

目的]探讨在大肠癌发生过程中错配修复基因hMLH1对p53基因突变的影响。方法]采用免疫组化SP法检测37例正常大肠黏膜、32例大肠腺瘤与165例大肠癌中P53及hMLHI蛋白的表达。结果]（D正常大肠黏膜组、大肠腺瘤组与大肠癌组P53蛋白的阳性表达率分别为0％、21．9％与48．5％，三组间差异有显著性意义（P〈0．05）；hMLH1蛋白的阳性表达率分别为100％、87．5％与87．3％，其中正常大肠黏膜组与大肠癌组的差异有显著性意义（P〈0．05）。②高中分化、低分化与黏液腺癌组中P53蛋白的阳性表达率分别为53．5％、17．6％与16．7％，其中前者与后两者的差异有显著性意义（P〈0．05）；hMLH1蛋白的阳性表达率分别为90．8％、70．6％与50．0％，前者明显高于后两者（P〈0．05）。③在大肠腺瘤轻中度不典型增生和重度不典型增生组中P53蛋白的阳性表达率分别为18．5％与40．0％（P〉0．05）；hMLH1蛋白的阳性表达率分别为92．6％与60．0％（P〈0．05）。④大肠腺瘤中随hMLH1蛋白的表达减少P53蛋白表达增多，但无明显相关性（P〉0．05）；大肠癌中两者的表达呈明显负相关（P〈0．05）。结论]大肠癌发生过程中hMLH1基因的功能异常可能是p53基因突变的原因之一．

Relationship between mutant P53 and hMLH1 in the carcinogenesis of colorectal carcinoma

Objective] To investigate the influence of mismatch repair gene hMLH1 on the mutating of p53 gene in the carcinogenesis of colorectal carcinoma.Method] Immunohistochemical method was used to detect P53 and hMLH1 protein in 37 cases normal colorectal tissues,32 cases colorectal adenomas and 165 cases colorectal carcinomas.Results] ①In normal colorectal tissue group,colorectal adenoma group and colorectal carcinoma group the expression rates of P53 protein were 0%,21.9% and 48.5% respectively,difference was significantly between them(P<0.05);the expression rates of hMLH1 protein were 100%,87.5% and 87.3% respectively,difference was significantly between normal colorectal tissue group and colorectal carcinoma group(P<0.05).②In high-or medium-differentiated adenocarcinoma group,low differentiated adenocarcinoma group and mucous adenocarcinoma group P53 protein positive expression rates were 53.5%,17.6% and 16.7% respectively,difference was significantly between the former and the latter two groups(P<0.05);hMLH1 positive expression rates in three groups were 90.8%,70.6% and 50.0% respectively,the latter two groups were obviously lower than the former group(P<0.05).③In moderate and severe atypical hyperplasia tissue groups,expression rates of P53 protein were 18.5% and 40.0%(P>0.05);expression rates of hMLH1 were 92.6% and 60.0%(P<0.05).④In colorectal adenomas,expression rates of P53 protein was increased with the decreasing of hMLH1,no significant correlation was between them(P>0.05);negative correlation was significantly between P53 and hMLH1 in colorectal carcinoma(P<0.05).Conclusion] Afunctional of hMLH1 gene may be one of the reasons for the mutation of p53 gene in the carcinogenesis of colorectal carcinoma.