[Expression of c-myc, c-erbB-2, insulin-like growth factor II andepidermal growth factor receptor in hepatitis B, cirrhosis and hepatocellular carcinoma].

In order to get a better understanding of expressions of multiple oncogenes and their possible roles in human hepatocarcinogenesis, 379 cases of liver tissues were investigated immunohistochemically. EGF receptors were immunolocalized mainly in the sinusoidal endothelial cells. They might not take part in the development of hepatocellular carcinoma (HCC), c-myc protein was showed to be expressed in cancer cells and the hepatocytes in the so-called "large-cell dysplasia" and in ductular metaplasia (DM). Its expression was also observed in some zone II hepatocytes of hepatic accini in 21% of normal liver tissues, which indicated that c-myc expression might also be related to the proliferation of mature hepatocytes. The positivity rate of c-erbB-2 product was shown to be highest among the oncogenic genes examined in this study. The positivity was observed in small polygonal liver cells (SPLCs) and the hepatocytes were observed in SCD and in DM. The expression level of c-erbB-2 oncogene in HCC cells was higher significantly than in normal hepatocytes, but lower than in SPLCs, the hepatocytes in SCD and in DM. We suggest that c-erbB-2 gene activation may play an important role not only in HCC genesis, but also in DM. Insulin-like growth factor II (IGF II), an oncofetal hepatocellular growth factor, was immunolocalized in the cancer cells, SPLCs and the hepatocytes in SCD, which indicated that activation and hyperexpression of IGF II gene might be responsible for the prominent proliferation of SPLCs and SCD, a crucial step in malignant transformation of hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS)