title: Expression of ras oncogene p21 protein in early gastric carcinoma and adjacent gastric epithelia.
abstract: The expression of the ras gene product p21 in normal gastric mucosa, early gastric carcinoma of diffuse (gastric) and intestinal types, and in adjacent mucosal abnormalities is reported. The analysis was performed on paraffin sections by an immunohistochemical assay using the mouse monoclonal antibody RAP-5 and the rat monoclonal antibody Y13-259. Expression of ras p21 was assessed by staining intensity and percentage of positively stained cells. In comparison to normal gastric mucosa of non-cancer patients, p21 was overexpressed in nearly all early carcinomas of both types and in the dysplastic and/or metaplastic mucosal alterations accompanying intestinal type of gastric cancer. Increased p21 expression was also observed in the normal-appearing mucosa adjacent to early carcinomas of diffuse type, but not in the morphologically normal gastric epithelium adjacent to the intestinal type. The results of this investigation suggest that ras p21 overexpression may be related to early events of human gastric carcinogenesis. The study supports the notion of different pathways in the development of diffuse (gastric) and intestinal types of gastric carcinomas.
authors.affiliation: Department of Pathology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York 10467.
authors.forename: B
authors.initials: B
authors.lastname: Czerniak
authors.forename: F
authors.initials: F
authors.lastname: Herz
authors.forename: W
authors.initials: W
authors.lastname: Gorczyca
authors.forename: L G
authors.initials: LG
authors.lastname: Koss
mesh_terms: D000230:Adenocarcinoma / Q000032:analysis*; D002288:Adenocarcinoma, Mucinous / Q000032:analysis; D000911:Antibodies, Monoclonal; D002277:Carcinoma / Q000032:analysis* / Q000145:classification; D003593:Cytoplasm / Q000032:analysis; D004848:Epithelium / Q000032:analysis; D005753:Gastric Mucosa / Q000032:analysis / Q000473:pathology; D006801:Humans; D008679:Metaplasia; D009363:Neoplasm Proteins / Q000032:analysis*; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D016283:Proto-Oncogene Proteins p21(ras); D013270:Stomach / Q000032:analysis* / Q000473:pathology; D013274:Stomach Neoplasms / Q000032:analysis* / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D009363:Neoplasm Proteins; D011518:Proto-Oncogene Proteins; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)