Monoclonal antibody COL-1 reacts with restricted epitopes on carcinoembryonic antigen: An immunohistochemical study

We used a monoclonal antibody, MAb COL-1, which recognizes a restricted epitope on the carcinoembryonic antigen (CEA) molecule, to stain a wide variety of human normal and cancerous tissues. None of the 35 different types of normal tissue stained with COL-1. Of 59 types of benign and malignant tissues, COL-1 reacted with neoplasms of epithelial origin, especially the gastrointestinal tract, breast, lung, and bladder. In benign adenomatous colon polyps, villous adenomas were more frequently stained than tubular adenomas. Normal colon tissue from individuals without colon disease was unreactive, but very weak reactivity was noted in normal-appearing mucosa several centimeters remote from colon cancers. In contrast, another anti-CEA antibody with a less restricted epitope reacted frequently with both normal and remote colon mucosa. These results indicate that MAb COL-1 recognizes a restricted CEA epitope expressed only on pre-malignant or malignant cells and therefore may be a useful reagent for immunopathology.