Evaluation of the ras and myc oncoproteins in benign gastric lesions.

Ras and c-myc oncoprotein expression was analyzed using specific monoclonal antibodies Y13-259 (for ras p21) and mycl-9E10 (for c-myc p62) in 144 histological sections derived from benign gastric lesions. Increased expression of ras p21 was observed in inflammatory metaplastic, dysplastic, hyperplastic and cystic histological changes, and on the basis of ras p21 staining three distinct histological groups emerged: (i) cystic changes, hyperplastic polyps; (ii) inflammatory gastritis; (iii) metaplastic, dysplastic and adenomatous polyps. Elevated levels of ras p21 expression were found at significantly higher levels than those of c-myc expression in dysplastic lesions. However the expression of the c-myc oncoprotein was less frequent than ras p21 in all other histological types. With the exception of parietal cells, normal stomach mucosa was found to express low levels of both ras p21 and c-myc oncoproteins.