MUC gene expression and histogenesis of adenocarcinoma of the stomach

To elucidate the histogenesis of adenocarcinomas of the stomach, we examine d MUC gene expression in gland-forming intramucosal neoplastic lesions. Eig hty tumors were histopathologically assigned to 1 of the following 3 groups based upon the Vienna classification: group A (low-grade adenoma/dysplasia ), group B (high-grade adenoma/dysplasia) and group C (intramucosal carcino ma). Immunohistochemic staining was performed with monoclonal antibodies ag ainst MUC2 (goblet cell mucin), MUC5AC (gastric-foveolar mucin), MUC6 (pylo ric-gland mucin) and CD 10 (brush border). Ki-67 staining was also carried out. An obvious difference existed in MUC gene expression between lesions i n group A and those in groups B and C. The majority of group A lesions stro ngly expressed intestinal markers in which proliferating cell zones were fo rmed but generally expressed no gastric markers, whereas more than 50% of g roups B and C tumors expressed gastric markers. These findings suggest that group A lesions are of a stable intestinal phenotype, whereas those in gro ups B and C are phenotypically and genotypically unstable, indicating that the adenoma-carcinoma sequence is not a major pathway, but instead that ade nocarcinomas arise de novo. (C) 2001 Wilev-Liss, Inc.