A NEW MURINE MONOCLONAL-ANTIBODY, CMU10, AS A MARKER FOR COLONIC-CARCINOMA AND PRECANCEROUS CONDITIONS

Objective.-To investigate the usefulness of a cancer-associated mucin antigen using a new monoclonal antibody, CMU10, as a tumor marker. Exp ression was assessed in normal adult, fetal, hyperplastic, preneoplast ic, and neoplastic tissues of colon. Design.-CMU10 monoclonal antibody recognizes a mucin antigen that is not expressed in normal fetal and adult large intestine, but is rather commonly expressed in cancerous a nd precancerous lesions. Immunocytochemical analysis was performed on human tissues obtained at surgery or at autopsy. Results.-Expression o f this mucin antigen was observed in 27 (98.4%) of 28 cases of colorec tal carcinoma, 24 (96%) of 25 cases of adenomatous polyps, 9 (75%) of 12 cases of ulcerative colitis, and 9 (100%) of 9 cases of hyperplasti c polyps. in cancerous specimens, the antigen distribution was mainly localized in the secretory mucin and surface membrane, whereas in prec ancerous lesions it was located in dysplastic, dilated, and distorted crypts. Conclusions.-Because CMU10 differentially recognizes an antige n in cancerous and precancerous tissues, but not in normal tissues, it may be useful as a tumor marker for immunodiagnosis and, hence, early detection.