Expression of c-ERBB Gene Family in Human Gastric Mucosa and Adenocarcinomas: Analysis by Immunohistochemistry and Western Blotting

Eri Ueno, Hiroyuki Shirai, Mitsuhiko Osaki, Hironobu Adachi and Hisao Ito

First Department of Pathology, Faculty of Medicine, Tottori University, Yonago 683, Japan

This study was conducted to examine the expression of c-ERBB1/EGFR (epidermal growth factor receptor), c-ERBB2 and c-ERBB3 gene products in 57 human gastric adenocarcinomas; 25 well differentiated and 32 poorly differentiated. A few epithelial cells in non-neoplastic mucosa showed immunoreactivity for c-ERBB2 and c-ERBB3 gene products in contrast to absence for EGFR. EGFR- and c-ERBB2- immune positive cancer cells were variably detected in 10 (17.5%) cases and in 25 (43.9%) cases, respectively. The incidence of these cancer cells was significantly higher (P < 0.05) in the well differentiated type than in the poorly differentiated type. Cancer cells with c-ERBB3 product were noted in 46 (80.7%) cases, regardless of their histological type. Western blot analysis revealed the expression of c-ERBB2 gene product in both carcinoma and non-neoplastic mucosa variably. Five of 14 cases showed higher expression of c-ERBB2 in carcinoma than in non-neoplastic mucosa. These results overall suggested that the c-ERBB gene family products play a crucial role in the progression of human gastric carcinoma, and that the c-ERBB3 gene product is the most significant among the three isotypes.

Key words: epidermal growth factor receptor family; gastric mucosa and carcinoma; immuno-histochemistry; Western blotting

RETURN