BACKGROUND: Hepatocellular carcinoma (HCC) is characterized by multiple causes, clear multiple stages and a multifocal process of tumor progression related intimately to the overexpression of many cellular factors. The aim of this study was to investigate the dynamic expression of insulin-like growth factor-Ⅱ (IGF-Ⅱ) and its abnormal alteration in the early stages of HCC development.
METHODS: Hepatoma models were induced by 2-fluorenylacetamide (2-FAA) in male Sprague-Dawley rats. Morphological changes of rat livers were assessed by pathological examination (HE staining). The levels of IGF-Ⅱ expression in the livers and sera of rats were quantitatively detected by an enzyme-linked immunosorbent assay (ELISA). Simultaneously, the expression and cellular distribution of liver IGF-Ⅱ were analyzed by immunohistochemistry.
RESULTS: Histological examination confirmed that rat hepatocytes showed changes from granule-like degeneration to atypical hyperplasia to HCC, and progressively increasing hepatic IGF-Ⅱ levels during HCC development. The levels of hepatic or serum IGF-Ⅱ in HCC tissues and sera were significantly higher than those in normals and rats with degeneration. The immunohistochemical evidence indicated the positive expression and hepatocyte distribution of IGF-Ⅱ in rat hepatoma. A positive relationship of IGF-Ⅱ levels was found between liver tissues and sera of experimental rats (P<0.01).
CONCLUSION: Hepatic IGF-Ⅱ may participate in hepatocyte cancer development and detection of IGF-Ⅱ expression during HCC development could be a useful molecular marker for its early diagnosis.