| Objective:To investigate the expression of MLH1,MSH2,MSH6 and PMS2 proteins in colorectal adenomatous polyps(adenomatous polyp)and colorectal cancer(colorectal cancer,CRC),to further understand the correlation between the two,and to explore their role in the progression of adenomas to cancer in order to provide a relevant possible basis for early detection of colorectal cancer.Methods:In this experiment,we selected 127 colorectal polyp specimens and 84 surgically removed colorectal cancer specimens from the people's Hospital of Cangzhou,affiliated to Chengde Medical College from 2017-09 to 2020-02.According to the pathological type,the colorectal polyp tissue was divided into tubular adenoma,mixed adenoma and villous adenoma.according to the diameter size,it was divided into 1cm > d,1? d ?2cm,2cm < d.the expression of MLH1,MSH2,MSH6 and PMS2 protein in colorectal cancer samples were detected by immunohistochemical method.Results:1.Among 127 cases of colorectal adenomatous polyps,the protein deletion rates of MLH1,MSH2,MSH6 and PMS2 in male and female were respectively:The deletion rate of MLH1 protein was 8.6%(6/70),8.8%(5/57),The deletion rate of MSH2 protein was 2.9%(2/70),1.8%(1.57),The deletion rate of MSH6 was 5.7%(4/70),3.5%(2/57)and The deletion rate of PMS2 was 18.6%(13/70),12.3%(7/57),The difference was no statistically significant(P >0.05).2.According to the adenoma diameters of 1cm > d,1? d ?2cm,2cm < d,the results were divided into three groups according to the above grouping: the deletion rate of MLH1 protein was 7.8%(7/90),6.1%(2/3),50.0%(2/4);the deletion rate of MSH2 protein was 1.1%(1/90),3.0%(1/3),18.2%(6/33);the deletion rate of MSH6 was 3.3%(3/90),3.0%(1/33),50.0%(2/4);and the deletion rate of PMS2 was 13.3%(12/90),18.2%(6/33),50.0%(2/4),The difference was statistically significant(P <0.05).3.The adenoma group was divided into tubular adenoma,mixed adenoma and villous adenoma.The results of the three types of adenomas wereasfollows: The deletion rate of MLH1 was 3.0%(2/66),17.4%(8/46),6.7%(1/15);The deletion rate of MSH2 was 1.5%(1/66),0%(0/46),13.3%(2/15);The deletion rate of MSH6 was 1.5%(1/66),4.3%(2/46),20.0%(3/15);And the deletion rate of PMS2 was 7.6%(5/66),26.1%(12/46),20.0%(3/15),The difference was statistically significant(P <0.05).4.In 84 colorectal cancer tissues,the deletion rate of MLH1 protein was 23.8%(20/84),the deletion rate of MSH2 protein was 13.0%(11/84),the deletion rate of MSH6 protein was 15.5%(13/84),the deletion rate of PMS2 protein was 29.8%(25/84),and the common deletion rate of four proteins was 8.3%(7/84),The difference was statistically significant(P <0.05).Conclusion:1.Expression of MLH1,MSH2,MSH6 and PMS2 proteins was absent in some colorectal adenomatous polyp tissues,independent of sex.2.As the diameter of the colorectal adenomatous polyps gradually increased,the expression rate of MLH1,MSH2,MSH6 and PMS2 protein deletion increased significantly.3.The greater the proportion of villi tissue components in colorectal adenomatous polyps,the higher the rate of MLH1,MSH2,MSH6 and PMS2 protein deletion.4.The overexpression of MLH1,MSH2,MSH6 and PMS2 is one of the hallmarks of malignant tumor hyperplasia,and its abnormal gene mutation is often expressed in different degrees before the occurrence and development of malignant tumor,suggesting that the deletion of mismatch repair gene may be one of the early manifestations of colorectal adenomatous polyp development to cancer. |
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