EXPRESSION OF NEURAL CELL-ADHESION MOLECULE IN NORMAL GASTRIC-MUCOSA AND IN GASTRIC CARCINOID-TUMORS

Expression of neural cell adhesion molecule (NCAM) in the digestive sy stem was studied with NE-150 monoclonal antibody, together with those against Lewis blood group antigens. NE-150 did not react with any of 3 2 cell lines tested derived from digestive tract cancers. In gastric a denocarcinomas NCAM was not expressed regardless of its differentiatio n status, while in gastric carcinoids and in other carcinoid tumors of different organs, it was present in all the specimens tested. Among n ormal tissues, it reacted with the deep gastric gland and the islets o f langerhans. These results suggest that NCAM is one of the most speci fic markers for gastric carcinoid tumors. It was also suggested that t he gastric carcinoid tumor might be derived from NCAM-positive cells i n the deep gastric gland. These findings should be exploitable in subg rouping gastric tumors in terms of antigen expression.