Decreased expression of CD44, alpha-catenin, and deleted colon carcinoma and altered expression of beta-catenin in ulcerative colitis-associated dysplasia and carcinoma, as compared with sporadic colon neoplasms

BACKGROUND. To clarify the cell adhesion status in ulcerative colitis (UC)- associated colon neoplasm, expression of cell adhesion molecules were inves tigated and compared with that of sporadic colon neoplasm. METHODS, A total of 14 low grade dysplasias, 16 high grade dysplasias, and 8 adenocarcinomas associated with UC and 17 sporadic adenomas with mild to moderate dysplasia, 22 adenomas with severe dysplasia, and 15 invasive aden ocarcinomas were immunohistochemically examined using monoclonal antibodies against CD44, E-cadherin, alpha- and beta-catenin, and deleted colon carci noma (DCC). RESULTS, CD44, especially its standard form, and DCC expression was stronge r in the sporadic colon neoplasms than in the UC-associated lesions. Althou gh E-cadherin did not show significant differences between the two cases, a lpha-catenin was more expressed in sporadic colon adenomas with severe dysp lasia and carcinomas than in their UC-associated counterparts. Membranous b eta-catenin staining was stronger in UC-associated neoplasms, whereas spora dic lesions had greater cytoplasmic and nuclear expression. CONCLUSIONS. The differences in cell adhesion molecule expression suggests that UC-associated and sporadic colon neoplasms arise from different pathwa ys of tumorigenesis. (C) 2000 American Cancer Society.