Expression of insulin‐like growth factor II, α‐fetoprotein and hepatitis B virus transcripts in human primary liver cancer

Insulin‐like growth factor II is a fetal growth factor structurally and functionally related to insulin and insulin‐like growth factor I. Its mRNA expression is developmentally regulated in human liver, the reexpression of insulin‐like growth factor II fetal transcripts being often observed in primary liver cancer. Insulin‐like growth factor II and α‐fetoprotein mRNAs were studied in 16 human primary liver cancers, most of which were highly differentiated. Hepatitis B virus transcripts were also analyzed in the tumors from hepatitis B virus chronic carriers. α‐Fetoprotein mRNA was detected in only four tumors and in one nontumorous cirrhotic tissue; all these samples also displayed insulin‐like growth factor II fetal transcripts. Furthermore, fetal insulin‐like growth factor II mRNAs were observed in five tumors and six nontumorous cirrhotic areas not expressing α‐fetoprotein mRNA. The presence of hepatitis B virus RNA was only observed in tissues not expressing α‐fetoprotein or fetal insulin‐like growth factor II mRNA. In conclusion, fetal insulin‐like growth factor II transcripts are more frequently observed than α‐fetoprotein mRNA in highly differentiated liver cancers and in surrounding cirrhotic areas. The reexpression of fetal insulin‐like growth factor II transcripts might then be a marker of early steps of liver cell transformation. (HEPATOLOGY 1991;13:644–649.)