Expression of MUC2 gene in gastric regenerative, metaplastic, and neoplastic epithelia

It has been reported that MUC2 mucin is expressed in goblet cells of gastri c intestinal metaplasia, but not in its normal epithelium. To confirm this finding, we have examined the expression of the MUC2 gene by reverse transc riptase-polymerase chain reaction and immunohistochemical methods in gastri c tissues obtained by routine upper gastrointestinal tract endoscopy and co mpared the results with pathological findings based on hematoxylin and eosi n (H&E) staining. In 16.7% of the tissue specimens tested, MUC2 mRNA was de tected in spite of the absence of intestinal metaplasia in HE specimens. A possible explanation for this was the identification by immunohistochemistr y of MUC2 protein in regenerative gastric mucosal cells in biopsies that di d not contain intestinal metaplasia. Sialyl-Le(x) epitope, which is suggest ed to be located on MUC2 mucin core protein (MUC2 protein), was also immuno histochemically detected in both goblet cells of intestinal metaplasia and regenerative epithelium. With regard to carcinoma, MUC2 protein was predomi nantly expressed in intestinal-type adenocarcinoma. These data indicate tha t MUC2 mucin is expressed in gastric regenerative epithelium in addition to intestinal metaplasia and intestinal type adenocarcinoma. J. Clin. Lab. An al. 13:259-265, 1999. (C) 1999 Wiley-Liss, Inc.