INSULIN-LIKE-GROWTH-FACTOR-II (IGF-II) SECRETED FROM HEPG2 HUMAN HEPATOCELLULAR-CARCINOMA CELLS SHOWS ANGIOGENIC ACTIVITY

Hepatocellular carcinoma (HCC) is a typical hypervascular tumor. Since insulin-like growth factor II (IGF-II) has been reported to play a si gnificant role in liver regeneration and hepatocarcinogenesis, we init ially examined its angiogenic effect on the chorioallantoic membrane ( CAM) of 9-day-old chick embryos. We also investigated whether IGF-II s ecreted from HepG2 human hepatocellular carcinoma cells induces vascul arization using the chick embryo CAM. We found that the concentrated c onditioned media (CCM) of HepG2 cell culture induced angiogenesis on t he CAM. We also identified IGF-II protein in the CCM from HepG2 cells by Western blot analysis. However, CCM from Chang liver cells, which a re normal human liver cells and were free of IGF-II, did not induce an giogenesis in the CAM. These results suggest that IGF-II secreted from hepatocellular carcinoma cells may act as an angiogenic factor for th e hypervascularization of HCC. (C) 1998 Elsevier Science Ireland Ltd.