Carcinoma-related alterations of glycosyltransferases in human tissues

The glycosyltransferases responsible for catalyzing additions of A, B, and H sugars to cellular acceptors were studied in 23 cases of primary carcinoma. The carcinomas were derived from mouth, tongue, larynx, lung, cervix, esophagus, stomach, and colon. Comparisons of A, B, and H enzymes were made between mucosal extracts from tumor and from normal adjacent tissue and, in the case of gastrointestinal tract, extracts derived from mucosae of individuals free of disease. The most prevalent finding was that of alpha-2-fucosyltransferase (H enzyme) deficiency in tumor extracts from Group A, B, and O patients in relation to the normal tissue counterpart (20 cases). Exceptions were observed in one case of carcinoma of the stomach and in two of seven cases of carcinoma of rectum or sigmoid. In four of nine Group A patients (carcinoma of the mouth, tongue, ascending and transverse colon), N-acetylgalactosaminyltransferases (A enzymes) were demonstrated but were deficient in relation to the normal adjacent counterpart. A enzymes were not demonstrable in normal and tumor extracts from distal colon in five cases. Differences between tumor extracts and normal adjacent tissue were noted in D-galactosyltransferase (B enzyme) derived from carcinomas of larynx and esophagus, but B enzyme was not demonstrated in tumor or normal tissue derived from the sigmoid colon. Study of the normal distribution of H enzyme in gastrointestinal mucosa indicated the presence of relatively high enzyme levels in stomach and upper intestine but low levels in distal colon.