title: Histologic demonstration of antigens reactive with anti-p21 ras monoclonal antibody (RAP-5) in human stomach cancers.
abstract: The immunohistochemical reactivity of RAP-5, a monoclonal antibody (MoAb) raised against a synthetic peptide corresponding to positions 10-17 of the ras gene product from T24 bladder carcinoma, was studied in 96 surgically resected stomach cancers of humans. The cytoplasm of cancer cells in 65 cases (68%) was positively stained with MoAb RAP-5, although the staining was heterogeneous among cancer cells. There was no definite correlation between depth of tumor invasion and reactivity to MoAb RAP-5. Cancer cells of poorly differentiated tumors showed a tendency to react less frequently and less intensely to MoAb RAP-5. In nontumorous gastric mucosa, parietal cells and some portions of intestinal metaplasia were stained with MoAb RAP-5. These findings suggest an increased expression of the ras gene product (p21) in about two-thirds of gastric adenocarcinomas and in some nonneoplastic gastric epithelial cells.
mesh_terms: D000911:Antibodies, Monoclonal; D003429:Cross Reactions; D006651:Histocytochemistry; D006801:Humans; D008207:Lymphatic Metastasis; D009857:Oncogenes; D011518:Proto-Oncogene Proteins / Q000032:analysis* / Q000276:immunology; D013274:Stomach Neoplasms / Q000032:analysis* / Q000235:genetics / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D011518:Proto-Oncogene Proteins