Expression of transforming growth factor alpha and epidermal growth factor receptor in human hepatocellular carcinoma

Abstract: Transforming growth factor alpha (TGF‐alpha) is thought to be involved in liver regeneration, cellular proliferation, and hepatocarcinog‐enesis. We have looked at the relationship between TGF‐alpha and it's receptor, and have attempted to relate the expression of TGF‐alpha and it's receptor to the differentiation of hepatocellular carcinoma (HCC) on serial sections of HCC. We examined immunohistochemically the expression of the TGF‐alpha and of epidermal growth factor receptor (EGFR) proteins in the same area of 53 nodules (<5 cm in diameter) of HCC obtained from patients. Immnnoreactive proteins were visualized by using a biotin‐streptoavidin system (LSAB Kit, Dako). TGF‐alpha was strongly expressed in 29 of 53 (54.7%) nodules. Specimens strongly positive for TGF‐alpha were found mainly in well‐differentiated HCC, while specimens positive for EGFR were found mainly in poorly differentiated HCC ( p <0.05). In the tissues that stained weakly positive for TGF‐alpha, the expression of EGFR differed significantly, according to the degree of HCC histologic differentiation ( p <0.05). These results led us to speculate that the expression of TGF‐alpha and EGFR might be related to the pattern of histologic differentiation of HCC.