MUC2 is a well-identified intestinal mucin, present predominantly in the small intestine and colon. It is known that pathological alterations in the expression and composition of this mucin occur in several serious diseases related to epithelial surfaces, e.g., carcinoma and colitis ulcerosa. In this study, our aim was to find out whether there are any specific alterations in the expression and secretion of MUC2 in an adenoma- adenocarcinoma sequence that has been established as an in vitro model (1,2). The adenoma-carcinoma sequence represents the first example of the malignant progression of human colonic adenoma cells in vitro (2,3). Using a novel approach that we established previously (4) ĞĞ the combination of density gradient centrifugation and agarose gel electrophoresisĞĞ we have characterised and compared the cell layer and medium MUC2 mucins among the colonic cell lines representing different stages of colorectal carcinogenesis. The results indicate that the expression and secretion of MUC2 mucin decrease from adenoma to adenocarcinoma. This is consistent with frequently observations in in vivo carcinogenesis (5) and strongly suggests that intestinal MUC2 mucins may be a useful marker for malignant transformation.

MUC2 is a well-identified intestinal mucin, present predominantly in the small intestine and colon. It is known that pathological alterations in the expression and composition of this mucin occur in several serious diseases related to epithelial surfaces, e.g., carcinoma and colitis ulcerosa. In this study, our aim was to find out whether there are any specific alterations in the expression and secretion of MUC2 in an adenoma- adenocarcinoma sequence that has been established as an in vitro model (1,2). The adenoma-carcinoma sequence represents the first example of the malignant progression of human colonic adenoma cells in vitro (2,3). Using a novel approach that we established previously (4) ĞĞ the combination of density gradient centrifugation and agarose gel electrophoresisĞĞ we have characterised and compared the cell layer and medium MUC2 mucins among the colonic cell lines representing different stages of colorectal carcinogenesis. The results indicate that the expression and secretion of MUC2 mucin decrease from adenoma to adenocarcinoma. This is consistent with frequently observations in in vivo carcinogenesis (5) and strongly suggests that intestinal MUC2 mucins may be a useful marker for malignant transformation.