Amphiregulin and epiregulin expression in neoplastic and inflammatory lesions in the colon.

Amphiregulin and epiregulin belong to the epidermal growth factor family and mediate the biological functions of epithelial and mesenchymal cells through epidermal growth factor receptors. In this study, we evaluated the amphiregulin and epiregulin expression in neoplastic and inflammatory lesions from the human colon. Surgically-obtained specimens were stained using standard immunohistochemical procedures. Amphiregulin and epiregulin were not expressed in the normal colonic mucosa, but were clearly detectable in adenomas and carcinomas. Weak immunostaining was also detected in mesenchymal cells from the tumor tissues. In the active mucosa of patients with ulcerative colitis and Crohn's disease, amphiregulin was mainly expressed by the epithelial cells. In addition, positive immunostaining was also detectable in the surrounding mesenchymal cells. In conclusion, amphiregulin and epiregulin may play important roles in colonic tumor growth and mucosal repair in the inflamed mucosa of inflammatory bowel disease.