Antigen Expression in Normal and Neoplastic Colonic Mucosa: Three Tissue-specific Antigens Using Monoclonal Antibodies to Isolated Colonic Glands

Abstract Monoclonal antibodies to normal colonic glands were used to localize three tissue-specific antigens in sections of 40 hyperplastic polyps, 29 adenomas, 43 colorectal adenocarcinomas, and blocks or rolls of histologically normal large bowel mucosa. Two antibodies identified antigens (designated 3NM and 17NM) associated with the mucin vacuole of goblet cells and the third antibody identified a cell membrane antigen (designated 6NM). Antigen 3NM was absent from virtually all carcinoma cells and from all, or most, cells of hyperplastic polyps. Antigen 17NM was absent from 21 carcinomas, with some antigen-positive cells present in the others. Antigen 6NM content was unchanged compared to normal mucosa in 12 carcinomas, decreased somewhat in another 20, and either absent or markedly depleted in 11. Antigen 6NM increased in 22 hyperplastic polyps. Three cancer patients synthesized 6NM in their normal mucosa but the cellular distribution was abnormal. Antigens decreased in most adenomas, with heterogeneity of expression seen in glands and cells of some adenomas. Low concentrations of one or more antigens in normal mucosa were significantly more frequent ( P