The Alterations Of E-cadherin And β-catenin And Their Significance During The Progression Of Gastric Carcinoma

Objective To study gene mutation of E-cadherin and β-catenin during the progression of gastric carcinoma, which related together with there immunohistochemical detection to explore the alterations and their significance of the heterogeneous expression of E-cadherin and β-catenin in the level of gene products.Methods CD PCR-SSCP-DNA sequencing: 35 specimens from primary site of gastric carcinoma and 10 specimens from peripheral tissues of gastric tumour were detected. By means of PCR-SSCP screened out the E-cadherin gene mutation in exon8,9 of and β-catenin gene mutation in exon3, and the positive results were confirmed by DNA sequencing. (2) Immunohistochemical PV-9000 methods:Using monoclonal antibodies for E-cadherin and β-catenin detected the corresponding paraffin embedded gastric carcinoma specimens to analyze their expression. (3) Statitical analysis :exect method(adoping the software of SPSS 12.0).Results ① gel electrophoresis showed single aimed band and PCR products were proved.②The results of PCR-SSCP displayed abnormal shifs were detected in exon8 of E-cadherin in 3 cases and in exon3 of β -catenin in 2 cases wherease abnormality was not found in exon9 of E-cadherin in 35 cases gastric carcinoma.All abnormalities belonged to undifferentiated gastric carcinoma.③DNA sequencing confirmed 4 cases gene mutation in 5 cases which were found abnormal shifs by PCR-SSCP. ④The conclusion of immunohistochemistry:No association was found between reduced expression of E-cadherin with tumour size, age, gender and lymphonode metastasis;Corresponding contrastive group was significantly higher than tumour (p = 0.0004, a <0.001), infiltrative tumour growth (p = 0.0005, a <0.001 ) and poor differentiation ( p = 0.0027, a <0.05 ) .There is no relationship of reduced β-catenin expression with tumour size, age and gender. The exprenssion of β-catenin with differentiation degree (p = 0.0085, a <0.05 ), the depth of invasiveness (p = 0.0085, a <0.05 ), lymphonode metastasis (p = 0.0064, a <0.05 ) and Lauren type (p = 0.0074, a <0.01) has significant relation.An association was found between reduced expression of E-cadherin and β-catenin, the relation coefficient was 0.686.