Immunohistochemical localization of the epithelial marker MAM-6 in ulcerative colitis and carcinoma of the large intestine

ABSTRACT

Milk fat globule membrane antigen [MAM-6] could be detected in the normal and neoplastic epithelial tissues. One of the exceptions of this finding is the normal mucosal epithelium of the large intestine which is negative for MAM-6 antigen. We examined the expression of MAM-6 antigen in 22 cases of colonic carcinoma. The antigen was expressed in 21/22 of the cases [95.4%]. In ulcerative colitis disease [U.C.] mildly or moderately active disease 7 cases did not express the MAM-6 antigen similar to the control. Severely active disease of U.C. without dysplasia expressed MAM-6 antigen in 4/8 of the cases [50%]. Severely active disease of U.C. associated with distinct areas of severe dysplasia expressede MAM-6 antigen in 6/7 of the cases [85.7%]. Expression of MAM-6 antigen in normal colonic mucosa was negative in all 30 cases which make up the control group in this study. T' ese data provide strong evidence that expression of MAM-6 antigen is directly related to the degree of disease activity and associated dysplasia and that there is a close relation between premalignant and malignant transformation of the large intestine. Expression of MAM-6 antigen could be a marker of dysplasia [Premalignant lesions of U.C.]