EXPRESSION OF TRANSFORMING GROWTH-FACTOR-ALPHA IN EXPERIMENTAL GASTRIC CARCINOGENESIS

The induction of adenocarcinomas in the glandular stomach of the adult male Wistar rat by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was us ed as a model to study the expression of the growth promoting peptide, transforming growth factor alpha (TGF alpha), during experimental gas tric carcinogenesis. TGF alpha was identified using the monoclonal ant ibody Ab-2 and standard immunohistochemistry, together with a semiquan titative assessment of the intensity of expression. Immunoreactivity w as confined to the differentiated compartment of the mucosa while the carcinogen MNNG caused a significant increase in the intensity of TGF alpha expression (p<0.01), after as little as 16 weeks' exposure. In e xperimental adenocarcinomas, a change to a previously undescribed patt ern of perinuclear TGF alpha expression was found, which may represent the site of intense TGF alpha production in the Golgi apparatus after malignant transformation.