This is an extensive study in a defined initiation-promotion hepatocellular carcinoma model of hepatocarcinogenesis (in rats) in which many important marker enzymes and isoenzymes and 8-hydroxydeoxyguanosine formation have been studied together with two very important cellular proliferating genes, insulin-like growth factor II and c-raf.1, known for their role in hepatocellular cancer development.
The high frequency of detection of hepatitis B virus X (HBV-X) antigen in liver cells from patients with chronic hepatitis, cirrhosis, and liver cancer suggested that the expressions of HBV-X and IGF-II are associated.
In conclusion, fetal insulin-like growth factor II transcripts are more frequently observed than alpha-fetoprotein mRNA in highly differentiated liver cancers and in surrounding cirrhotic areas.
An increased synthesis of IGF-II protein was demonstrated by a protein-binding assay in tumorous liver samples, the highest levels being found in primary liver cancers with the highest IGF-II steady state level.
Furthermore, these results indicate a differential expression of IGF-II transcripts in nonmalignant hepatocyte proliferation (benign liver tumors and cirrhosis) as compared to liver cancer.