Research On The Relationship Of SFRP1 Promoter Methylation And Expression Of β-catenin,E-cadherin In Infiltrating Breast Cancer

ObjectiveTo detect the methylation status of SFRP1 gene and the expression of SFRP1,β-catenin,E-cadherin protein in infiltrating breast cancer and adjacent normal breast tissue, to analyze the relationship between the methylation of SFRP1 gene and the expression of protein, to discuss the role of the methylation of SFRP1 gene in the development of infiltrating breast cancer.MethodDNA from 50 cases of fresh infiltrating breast cancer and 12 cases of adjacent normal breast tissue was extracted by DNA extraction kit. To bisulfite modify the extracted DNA, to detect the methylation status of SFRP1 gene by methylation specific PCR in all samples; To detect the expression of SFRP1,β-catenin,E-cadherin protein in all samples by immunohistochchemistry PV two-step method.Results①The detection rate of the methylation of SFRP1 gene in 50 cases of infiltrating breast cancer 46.00% (23/50),is significantly higher than 12 cases of adjacent normal breast tissue 8.33%(1/12). With the increase of TNM stage of infiltrating breast cancer, the detection rate of the methylation of SFRP1 gene in infiltrating breast cancer increased.②21 cases of negative and 3 cases of positive expression of SFRP1 protein in 24 cases of SFRP1 methylated samples. The methylation s of SFRP1 gene and the expression of SFRP1 protein showed a significantly negative correlation(r =-0.451,P< 0.001).③The positive expression rate of SFRP1 protein in infiltrating breast cancer 32.00%(16/50)is significantly lower than adjacent normal breast tissue 75.00%(9/12),and is related to the TNM staging; The positive expression rate ofβ-catenin, E-cadherin protein in infiltrating breast cancer 72.00%(36/50),64.00% ( 32/50 ) is significantly higher than adjacent normal breast tissue25.00%(3/12),16.67%(2/12). The positive expression rate ofβ-catenin protein is related to TNM staging and ER receptor, the positive expression rate of E-cadherin protein is related to TNM staging and axillary lymph node metastasis.④The expression of SFRP1 protein and the abnormal expression ofβ-catenin protein in infiltrating breast cancer showed a significantly negative correlation(r=-0.432,P<0.05),the expression of SFRP1 protein and the abnormal expression of E-cadherin protein also showed a significantly negative correlation(r=-0.379,P<0.05).Conclusions①SFRP1 gene promoter CpG island methylation in infiltrating breast cancer is higher than in adjacent normal breast tissue.②The expression of SFRP1 protein in infiltrating breast cancer reduced or absent.③SFRP1 gene promoter methylation may be one of the main reason of the absence expression of SFRP1 protein in infiltrating breast cancer.④The abnormal expression ofβ-catenin, E-cadherin protein in infiltrating breast cancer may be related to the reduced or absent expression of SFRP1.⑤SFRP1 gene methylation may be through decreasing SFRP1 protein expression, decreased the inhibition to the wnt signaling pathway, wnt signaling pathway actived abnormally, which led to the occurrence of infiltrating breast cancer. This may be provide certain molecular basis to the early detection, diagnosis and treatment of infiltrating breast cancer.