EXPRESSION OF Ha-ras ONCOGENE PRODUCT, p21 IN GASTRIC CARCINOMA

Abstract

Immunohistochemical reactivity of antibody against a synthetic peptide corresponding to positions 160-179 of the Ha-ras gene product was studied in 67 (78 lesions) surgically resected stomach cancers of humans. The cytoplasma of cancer cells in 31 of 78 lesions (39.7%) was positively stained. Staining positivity of advanced type carcinoma was accentuated than that of early type carcinoma. However, there was no correlation between depth of gastric carcinoma invasion and ras p21 expression. Immunoperoxidase staining pattern of these tumors was shown by the strong expression of ras p21 in more superficial glands versus the lesser amount of ras p21 expression in deeply invasive glands. Cancer cells of well differentiated type showed to react more frequently to antibody. In nontumorous gastric mucosa, some portions of regenerating epithelial cells and intestinal metaplasia were stained with antibody.