Expression Of Mismatch Repair Gene HMLH1,hMSH2 And PMS2 In Sporadic Colorectal Carcinomas

Colorectal cancer(CRC)as a kind of common malignant tumor,it is very common in our country,its incidence ranked second in the digestive system tumors,and has a tendency to rise year by year.Even in a foreign country in third place in the digestive system tumor,the mortality rate has been high.Colorectal cancer can be roughly divided into three categories,they are familial adenomatous polyposis(FAP),hereditary not Colorectal polyps(HNPCC)and sporadic colorectal cancer(SCRC),the occurrence of the first two closely associated with genetic factors,sporadic colorectal cancer,also known as hereditary colorectal cancer.With the 1993 microsatellite instability(MSI)was found,a new way,mismatch repair(MMR)way to begin to be recognized,there have been studies confirming that more than 10% of sporadic colorectal cancer and nearly all hereditary non polyps are microsatellite instability in colorectal cancer.Most studies confirm that Mismatched repair genes involved in tumor development,development,metastasis and prognosis,HMLH1,hMSH2,and PMS2 as common mismatched repair genes are closely associated with sporadic colorectal cancer,but the relationship between their expression and the clinical pathologic parameters of sporadic colorectal cancer has no uniform understanding,The presentation of the three proteins was important for the clinical treatment and prognosis of patients with sporadic colorectal cancer.Therefore research on this topic,and report as follows:Objective: To detect the expression of hMLH1,h MSH2 or PMS2 protein in the expression of sporadic colorectal cancer and with the relationship between the clinical pathological parameters.Methods:1 15 cases of colorectal adenomas,the corresponding normal tissue adjacent to carcinoma(distance from tumor cut edge > 5 cm)15 cases and 90 cases of SCRC were studied,who underwent surgery in the first affiliated hospital of Hebei North University from 2015 to 2016.All the patients were diagnosed by histological examination without chemoradiotherapy before operation.2 Immunohistochemistry(IHC)was used to detect the hMLH1,hMSH2 or PMS2 protein expression in the tumor tissues from 90 cases of SCRC.The relationship of its expression to clinicopathologic parameters was analyzed.3 Data analysis using SPSS17.0 software,and the analysis of various clinical pathologic factors and the expression of various proteins and the correlation analysis between the proteins was chosen by chi square test,P < 0.05 is statistically significant.Results:1 IHC detection results: the 15 cases of adjacent normal tissue protein expression were positive;There were 7 cases of colorectal adenoma in,the expression of MMR protein was absent,the deletion rate was 46.7%.The deletion rate of hMLH1 protein was 20%(3/15),and the deletion rate of hMSH2 protein expression was 6.7%(1/15).The deletion rate of PMS2 protein expression was 26.7%(4/15).And there were 1 cases of h MLH1/ PMS2 deletion,the deletion rate was(1/15).The loss rates of hMLH1,hMSH2,and PMS2 expressions in the tumor tissues from 90 patients with SCRC were 13.3%(12/90),12.2%(11/90),and 12.2%(11/90),respectively HMLH1 and hMSH2 express absence rate was 3.3%(3/90),hMLH1 / PMS2 express absence rate was 10.0%(9/90),hMSH2 / PMS2 express absence rate was 6.7%(6/90),hMLH1 and hMSH2 / PMS2 express absence rate was 1.1%(1/90).2 Relationship between the expression of hMLH1,hMSH2,PMS2 protein and clinicopathological parameters in patients with SCRC: the deletion rates of the three proteins were different in normal tissues and colorectal adenomas and colorectal carcinoma tissues(P<0.05).The deletion rate of hMLH1 and PMS2 protein was significantly higher than that of hMSH2,but there was no significant difference(P>0.05).Results in 90 cases of colorectal carcinoma: the deletion rate of MLH1 protein was not associated with other factors(P>0.05),it was only related to the degree of differentiation,and the low differentiated state(57.1%)was significantly higher than that in the middle differentiation(10.7%)and the highly differentiated state(7.4%)(P<0.05);the loss rate of hMLH2 expression there was no significant difference in age,gender,tumor location,tumor differentiation,lymph node metastasis(P>0.05),there was associated with tumor size(P<0.05),tumor diameter greater than 5cm(24.14%)was significantly higher than the tumor diameter less than 5cm(6.56%);The loss rate of PMS2 expression there was no significant difference in gender,age,lymph node metastasis(P>0.05),there was associated with tumor location and differentiation(P<0.05).The right half colon cancer(30%)higher than the left half colon cancer(5.6%)and colon cancer(8.8%).The state of low differentiation(57.1%)was higher than that of middle differentiation(5.4%)and high differentiation(14.8%).3 HMLH1 and hMSH2 and PMS2 in SCRC expressed in tumor tissues of relevance: HMLH1 and PMS2 expression were positively correlated(P = 0.000),HMSH2 and PMS2 expression also were positively correlated(P = 0.045),the expression of hMLH1 and hMSH2 no significant correlation(P = 0.328).Conclusions:1 Mismatched repair genes hMLH1,hMSH2,and PMS2 were expressed in sporadic colorectal cancer.2 HMLH1,hMSH2,and PMS2 indirectly reflect the biological behavior of sporadic colorectal cancer,as an indicator of the progress and prognosis of sporadic colorectal cancer.3 HMLH1,h MSH2,and PMS2 genes interact with each other,and they are often co expressed or deleted,therefore,combined detection of three proteins can improve the detection rate of protein loss.