Transforming growth factor alpha expression in normal gastric mucosa, intestinal metaplasia, dysplasia and gastric carcinoma--an immunohistochemical study.

Using a monoclonal antibody (GF10) and a standard immunohistochemical technique, immuno-expression of transforming growth factor alpha (TGF-alpha) was found consistently within the differentiated compartment of normal adult human gastric mucosa. In 70% of mucosal samples exhibiting intestinal metaplasia there was more or less uniform TGF-alpha immunoreactivity throughout the intestinalized mucosa. Similarly, 60% of cases of dysplasia and 60% of gastric carcinomas showed strong immunoreactivity in most of the cells. However, whereas 93% of intestinal-type cancers showed strong immunoreactivity only 30% of the diffuse type were stained and then only weakly. Transforming growth factor alpha expression is thus a fairly regular feature of several types of differentiated gastric epithelia (normal, metaplastic, dysplastic and intestinal-type carcinoma), while its relative absence may be a factor in the histogenesis of the diffuse type of gastric carcinoma.