E-cadherin And β-catenin Expressions In Bladder Transitional Cell Carcinoma And Predictive Value

The process of infiltration and matastasis of tumor, at first, begin with the alternative process of adhesiveness and deadhesiveness. It is generally acknowledged that there existed reduced adhesiveness among tumor cells. More and more proof suggested that intimate relationship presents between the process of infiltration and matastasis of tumor and the adhesive system mediated by multiple adhesive factors, especially E - cadherin ( E - cad ). As an important adhesive factor mediating cellular adhesiveness and tissue integration, E - cad can produce a marked effect only in form of complex with catenin. By now, 4 iso-forms of catenin have been found: - catenin, β - catenin , r - catenin and P120. The catenin link the intra - membranous part of E -cad with cytoskeleton to set up stable and firm intercellular adhesiveness. Any abnormality in the complex of cadherin and catenin will cause the loss of cellular adhesiveness. Bladder carcinoma is the most common malignant tumor of urinary system, so immunohistochemistry method was used in this study to investigate the expression and correlation of E - cad and β - catenin( β - cat) in bladder carcinoma and the relationship between them and pathological grade, clinical stage and prognosis of bladder carcinoma.MethodsTumor group: Paraffin embedded tumor specimens were obtained from 68 patients who underwent surgery for bladder transitional cell carcinoma in Department of Urology, the First Affiliated Hospital of China Medical University from 1994 to 1996, and the diagnosis of bladder carcinoma was confirmed by pathologist. 57 cases are male, 11 cases female, and the age ranges from 32 to 84(61. 2 in average). Tumor stage was determined according to the criterion of WHO on cancer. 17 cases are of G1, 22 cases of G2, and 29 cases of G3. While tumor grade was determined according to the TNM method proposed by UICC. 23 cases are of Ta ~ T1, 45 cases of T2 ~ T4. Normal control group: 10 cases of normal bladder mucosa tissue were obtained from the open surgery because of hyperplasia of prostate. All the samples were sliced up serially with thickness of 5 um. Immunohistochem-istry S - P method and HE staining were performed. Purchased positive control picture is used as positive control, and PBS solution replacing first antibody as negative control. E - cad andp - cat are expressed in all cells of normal bladder mucosa with uniform brown -stained membranes. Normal expression of E - cad and β - cat in tumor tissue is defined as the same expression way and intensity as normal tissue. While abnormal expression is defined as less than 90% positive cells or brown - stained plasma or nuclei only.The relationships between E - cad, β - cat expression in bladdercarcinoma and tumor grades and clinical stages were evaluated by chi- square test. Correlation between two indexes was analyzed bySpearman correlation test. The different expressions of E - cad andβ- cat in tumor survival were evaluated by Kaplan - Meier method and differences were evaluated by log rank test.ResultsThe abnormal expression rate of E - cad and β - cat were 69.1% and 77.9% respectively, In 58 cases (85.3% ) , the expressions of E - cad and β - cat were abnormal or normal simultaneously, and significant correlation between them were suggested by the Spearman correlation analysis ( r = 0. 642, P < 0.05 ) . The abnormal expression rate of E - cad andp - cat in G1, G2 and G3 were 35. 3% ,63. 6% ,93. 1% and 47.1% ,77. 3% ,96. 6% respectively;and their abnormal expression rate in Ta - T1 ,T2 - T4 were 30. 4% ,88. 9% and 47. 8% , 93.3% respectively, and there was significant difference present a-bout the abnormal expression rate of E - cad andβ - cat among pathological grades and clinical stages ( P < 0. 05 ). Significant difference present( P < 0. 05 ) were confirmed by compared the Kaplan - meier curve of normal expression of E - cad in 21 cases with that of abnormal expression in 47 cases. The same results was observed when compared the Kaplan - meier curve of normal e...