Re-expression Of E-cadherin And β-catenin In Human Advanced Gastric Carcinoma And Its Clinical Significance

Objective: To investigate the re-expression of E-cadherin andβ-catenin in cancerous cells of metastatic lymph nodes from advanced gastric carcinoma,and evaluate its clinical significance, and try to find a kind of more sensitive and reliable method for early diagnosis and remedy in a molecule level of gastric carcinoma.Methods:Immunohistochemical(stroptavidin-perosidase,S-P) technique was applied to investigate the expression of E-cadherin andβ-catenin in primary advanced gastric carcinoma and compare with the expression level in cancerous cells from metastatic lymph nodes of 42 advanced gastric carcinomas.The expression of E-cadherin mRNA andβ-catenin mRNA was detected to the above samples by the way of RT-PCR, E-cadherin andβ-catenin was detected by the way of western-blot. Combined with the clinicopathological factors such as degree of differentiation, histologic type, depth of invasion,Tumor size,to observe the expressions of E-cadherin andβ-Catenin.Results: (1) Immunohistochemistry: The color of the immune positive products of E-cadherin/β-catenin was buffy and located in plasmalemma.Of all42 cases of advanced gastric carcinoma, the abnormal expression rates of E-cadherin in primary advanced gastric carcinoma was 90.5% (38/42),and the re-expression rate of E-cadherin in metastasis lymph node was 28.6% (12/42). the abnormal expression rates ofβ-Catenin in primary advanced gastric carcinoma was 80.9%(34/42),and the re-expression rate ofβ-Catenin in metastasis lymph node was 52.4% (22/42). The re-expression rate of E-cadherin/β-Catenin in well-differentiated carcinoma was significantly higher than that in poorly differentiated gastric carcinoma(P<0.05). The re-expression rate of E-cadherin/β-Catenin in tubular adenocarcinoma was not significantly different than that in mucous adenocarcinoma(P>0.05).⑵RT-PCR: there were different expression of E-cadherin mRNA andβ-Catenin mRNA in 42 cases of hunman advanced gastric carcinoma and metastasis lymph node. The relative value of E-cadherin mRNA expression in advanced gastric carcinoma was (0.7441±0.0114),and that in normal tissue was (0.8037±0.0114). The difference has statistical significance(P<0.05). The relative value ofβ-Catenin mRNA expression in advanced gastric carcinoma was (0.6071±0.1054),and that in normal tissue was (0.8123±0.0115). The difference has statistical significance(P<0.05). The result from RT-PCR indicated that expression of E-cadherin mRNA/β-Catenin mRNA in metastasis lymph node were significantly correlated to the tumor differentiation degree and histologic type.(3)The different expression levels of E-cadherin /β-Catenin protein were detected in all 42 cases from primary advanced gastric carcinoma and their corresponding metastatic lymph nodes. In primary foci , the protein relative strength of E-cadherin was 6～113.8(60.80±26.1), in metastatic lymph nodes, that was 16～158.2(88.3±38.87). The protein relative strength ofβ-catenin was 21～132(58.69±30.3), in metastatic lymph nodes, that was 16～101(63.67±25.9).The relative intensity of E-cadherin/β-catenin protein expression in primary foci was lower than that in metastatic lymph nodes.The relative intensity in metastatic lymph nodes from well-differentiated cancer was higher than that from poorly differentiated cancer.(4)Comparison of the re-expression of E-cadherin andβ-catenin make use of association test in metastasis lymph node , come to E-cadherin andβ-catenin are associated.Conclusion: E-cadherin andβ-catenin expression may be closely correlated to the occurrence, the advancement and the metastasis of gastric carcinoma. The E-cadherin re-expression of cancerous cells in metastatic lymph nodes from advanced gastric carcinoma may be derived from the repair of gene mutation.The re-expression ofβ-catenin in metastatic lymph nodes were significantly correlated to the tumors differentiation degree and its invasion depth,but not to the tumors size and its histology type. The re-expression of E-cadherin in metastatic lymph nodes were significantly correlated to the tumors differentiation degree and its histology type,but not to the tumors size and its invasion depth. Comparison of the re-expression of E-cadherin andβ-catenin make use ofassociation test in metastasis lymph node , come to E-cadherin andβ-catenin are associated.