The Expressions Of β-catenin And E-cadherin In Gastric Carcinoma And The Significance To The Pathobiological Characteristics

Nowadays, the research of the initiation and development of the gastric carcinoma and effective treatment is still one of the most important subjects to our national medicine, even though the global medicine. At present, the "focused spot" of the gastric carcinoma research is the initiation, development and metastasis. Among those, beta -catenin and E - cadherin have been paid more attention to because of their key role in the cadherin/catenin system and WNT signaling pathway. It has the important significance to research the relationship between the expressions of β - catenin and E - cadherin and the pathobi-ological characteristics of gastric carcinoma. And it maybe benefit to grasp the mechanism of gastric carcinoma initiation, judge the state of lymph node metastasis and decide clinical treatment plans.In our experiment, the immunohistochemistry method was performed to detect the expressions of β - catenin and E - cadherin in 34 EGC cases and 57 AGC cases. And the Western Blot was performed to detect the quantity differences between the cancer tissue and normal tissue. The goal is to discuss the relationship between the expressions of the two molecules and the pathobiological characteristics and the possibility to direct the clinical treatment and judge of the prognosis.Materials and MethodsI . Materials1. Samples All EGG and AGC samples used in immunohisto-chemical study and Western Blot were obtained from the surgical resected specimens of patients admitted to the 1st Affiliated Hospital of China Medical University during 2001 -2002. One piece of the carcinoma tissue was fixed in 10% formalin and embedded in paraffin. The other piece and normal tissue samples were preserved at -70℃.2. Reagents The mouse - anti - human monoclonal antibody of β - catenin ( Transduction Biological company) , the rabbit - anti -human monoclonal antibody of E - cadherin ( Boster Biological company ) ; the immunohistochemistry ultrasensitive S - P kit ( Maxin Biological company) ; the phosphatase labeled goat - anti - mouse secondary antibody and BCIP/NBT kit ( Huamei Biological company) ; the other reagents made in China were all analytical pure.II. Methods1. ImmunohistochemistryDetect the expressions of β - catenin and E - cadherin by immunohistochemistry S - P method. The evaluation standards: the normal positive expressions of β - catenin and E - cadherin were located at the cell membrane as the brown - yellow granular staining. 100 cancer cells were counted respectively in each 5 fields which were selected at random. We used a scoring system to evaluate the immunoexpression, judging the cases with brown plasma/membrane staining as positive. More than 90% of the tumor cells were stained positively, we consider the case is normal expression; otherwise, less than 90% cells expresspositively, or expression is located in the cytoplasm or nucleus are all considered abnormal.2. Western BlotRapidly homogenize the carcinoma and normal tissues in 400ul lysis buffer and centrifuge the homogenate (1000rpm, 4℃ ) for 30 minutes to pellet insoluble material. ①Electrophoresis ② transfer proteins from gel to PVDF membrane ③blocking ④incubation with the primary antibody then the secondary antibody ⑤enzyme conjugate incubation ⑥substrate incubation. ⑦scan the results to computer1. III. Statistical analysisSPSS for Windows 10.0 statistical software was used to solve the result and analyze the differences. Paired - samples t test was used to solve the result of Western Blot. The significant statistical level was p <0.05.ResultI . Results of Immunohistochemistry1. In 10 cases of normal gastric tissues, the positive expressions of β - catenin and E - cadherin were located at the side - to - side connection spot on membrane, and no abnormal expressions were observed. In 34 cases of EGC, the abnormal expression ratios of β - cat and E - cd are 35.29% and 38.24% respectively; in 57 cases of neoplasm tissues, the ratios are 40.35% and 56.14% respectively, and th...