The Expression Of HMLH1,hMSH2 In Laryngeal Carcinoma And The Correlation With Apoptosis

Objective: The carcinoma of larynx is one of the malignant neoplasm in otolaryngology and head and neck surgery. The etiology of laryngeal carcinoma is concerned with the changed related genetic expression which caused by a deal of factors as well as other kinds of carcinomas. The mismatch repair genes can maintain the constancy of genes. Mismatch repair system not only correct base mispairing of DNA to keep the stabilization of genomics but also lead the apoptosis of the cells of which DNA is impaired seriously to abscise the cancer.In our study,our aim is to investigate the correlation between the expression of hMLH1,hMSH2 and the development of the cancer of larynx and the relationship with apoptosis of laryngeal carcinoma cell.Methods:1 Immunohistochemistry for hMLH1,hMSH2 expression was performed on cryostat section from 40 laryngeal carcinoma ,19 para-carcinoma and 12 normal laryngeal mucosa specimens.2 Flow Cytometrye(FCM) for hMLH1,hMSH2 expression was performed from 40 laryngeal carcinoma ,40 para-carcinoma and 15 normal laryngeal mucosa specimens.3 SPSS 11.5 was applied to analyze the results of experiment.P≤0.05 indicating significant difference.P≤0.01 indicating very significant difference.Results:1 The expression of hMLH1 protein1.1 The results detected by IHC : The expression of hMLH1 ancensus from laryngocarcinoma to para-carcinoma and normal laryngeal mucosa tissues , there is statistic significance(P<0.01).The expression of hMLH1 in laryngocarcinoma is relatively weaker than those in para-carcinoma(P<0.01)and in normal laryngeal mucosa(P<0.01)tissues respectively.No significant difference was found between the expression of para-carcinoma and normal laryngeal mucosa tissues(P>0.05). Expression of hMLH1 was correlated with lymph node metastasis, clinical stage and pathological grading of tumor(P<0.05), but that wasn't correlated with patients'clinical classification, tumor size, smoking history, patients'age and sex(P>0.05).1.2 The results detected by FCM:the quantitative expression of hMLH1 protein (FI=0.8960±0.1751) in laryngeal carcinoma tissues is relatively weaker than those in para- carcinoma(0.9867±0.1609,P<0.05)and in normal laryngeal mucosa(1.0002±0.1490,P<0.05)tissues respectively.We found no significant difference between the expression of para- carcinoma and normal laryngeal mucosa tissues (P >0.05). Expression of hMLH1 was correlated with lymph node metastasis, clinical stage and pathological grading of tumor (P<0.05).2 The expression of hMSH2 protein2.1 The results detected by IHC : The expression of hMSH2 ancensus from laryngocarcinoma to para-carcinoma and normal laryngeal mucosa tissues , there is statistic significance(P<0.01). the expression of hMSH2 in laryngocarcinoma is relatively weaker than those in para-carcinoma(P<0.01)and in normal laryngeal mucosa(P <0.01)tissues respectively,we found no significant difference between the expression of para- carcinoma and normal laryngeal mucosa tissues(P>0.05). Expression of hMSH2 was correlated with lymph node metastasis, clinical stage and pathological grading of tumor (P<0.05), but that wasn't correlated with patients'clinical classification, tumor size, smoking history, patients'age and sex(P>0.05).2.2 The results detected by FCM:the quantitative expression of hMSH2 protein(FI=0.8929±0.1861) in laryngeal carcinoma tissues is relatively weaker than those in para- carcinoma(0.9899±0.1365,P<0.05)and in normal laryngeal mucosa(1.0000±0.1073,P<0.05)tissues respectively ,no significant difference was found between the expression of para-carcinoma and normal laryngeal mucosa tissues (P >0.05). Expression of hMSH2 was correlated with lymph node metastasis, clinical stage and pathological grading of tumor (P<0.05).3 The results detected by FCM:There is a positive correlation between the quantitative expression of hMLH1 protein in laryngeal carcinoma tissues and the expression of hMSH2(r=0.933,P=0.000).The regression equation is Y=1.005X-0.007.4 In the hMLH1 positive group the apoptosis rate(AP) is 8.6144±0.6315%, which is much stronger than the rate 5.3841±1.3673% in negative group .There is statistic significance(P=0.000).We found a positive correlation between the quantitative index of hMLH1 protein and apoptosis rate(r=0.711,P=0.000).The regression equation is Y=7.949X-0.285.5 In the hMSH2 positive group the apoptosis rate is 8.2957±1.0079%, which is much stronger than the rate 5.2263±1.3955% in negative group. There is statistic significance(P=0.000).We found a positive correlation between the quantitative index of hMSH2 protein and apoptosis rate(r=0.720,P=0.000).The regression equation is Y=7.477X+0.161.Conclusions:1 Both hMLH1 and hMSH2 protein express in all laryngeal carcinoma, para-carcinoma mucosa and normal mucosa tissues.2 The quantitative and qualitative expression of hMLH1 and hMSH2 protein in laryngeal carcinoma tissues are relatively weaker than those in para-carcinoma and in normal laryngeal mucosa tissues respectively, may contribute to the carcinogenesis and development of laryngeal carcinoma.3 The weaker expression of hMLH1 and hMSH2 protein are correlated with malignant biological behavior of laryngeal squamous cell carcinoma, which included lymph node metastasise , patients'clinical classification and pathological grading of the tumor. The expression of hMLH1 and hMSH2 aren't related to tumor size, smoking history, patients'age and sex.4 There is a positive correlation between the quantitative expression of hMLH1 and hMSH2.5 There is an direct correlation between the quantitative index of hMLH1 and hMSH2 protein and laryngeal carcinoma cell apoptotic rate.6 hMLH1 and hMSH2 probably takes part in laryngeal carcinoma genesis and growth through promoting apoptosis.