Glycoconjugate with Ulex europaeus agglutinin-I-binding sites in normal mucosa, adenoma, and carcinoma of the human large bowel

Abstract

Cancerous lesions and nonneoplastic mucosa of surgically extirpated specimens from 94 patients with colorectal carcinoma (of the right colon, 31 patients; of the left colon, 29 patients; and of the rectum, 34 patients) and endoscopically polypectomized specimens from 18 patients with rectal adenoma were examined with fluorescein isothiocyanate-conjugated or horse-radish peroxidase-conjugated Ulex europaeus agglutinin-I (UEA-I) specific to a certain terminal alpha-L-fucosyl residue in glycoconjugates. Of the 31 patients with right colon cancers, 22 showed positive UEA-I binding in the neoplastic cell apexes, apical luminal borders, and luminal secretions. The adjacent nonneoplastic mucosa of all 31 patients, however, demonstrated positive UEA-I binding in the goblet cell mucus. UEA-I binding was positive for 23 of the 29 left colon cancers and for 28 of the 34 rectal cancers, although UEA-I binding was not revealed in the adjacent nonneoplastic mucosa for most of the cases. Of the 18 rectal adenomas, 12 specimens showed positive UEA-I binding in the apical secretions of their adenoma cells. Marked regional differences of UEA-I binding in the nonneoplastic mucosae indicated that the constituents of glycoprotein with UEA-I binding sites in goblet cell mucus differed significantly between the human right and left large bowels. Positive UEA-I binding in many rectal cancerous and adenomatous lesions suggested that a neoplastic glycoprotein with alpha-L-fucosyl residue was produced or that the terminal carbohydrate structure of glycoprotein present in the nonneoplastic mucosa was altered to bind easily with UEA-I after the neoplastic transformation had occurred. A possible relation of this UEA-I binding to blood group H(O) substance is discussed.