Objective: The expression of insulin-like growth factor I receptor (IGF-IR) and the vascular endothelial growth factor (VEGF) in HepG(2) cells transfected with a hepatitis B virus X (HBx) expression vector was investigated in an attempt to study their possible relationship to the growth of HBx-induced hepatocellular carcinoma (HCC).
Methods: The eucaryotic expression vector of HBx gene was constructed and introduced into HepG(2) cells. The modified cell HepaG(2)-X was synchronized in a quiescent state by culture of serum deprivation. The IGF-IR and VEGF were analyzed by immunohistochemical and Western blot technique.
Results: The positive rate of IGF-IR expression was 84%A3% in the transfected HBx gene cells, 26%A4% in X(0) control cells. The positive rate of VEGF expressed x cells was 83%A5%, X(0) cells was 28%A6% (P<0.001). The level of IGF-IR and VEGF in serum-starved x modified cells was 1.5 times higher than that of synchronized X(0) modified cells.
Conclusion: Since the IGF-IR is a very important growth factor in sustaining the tumor abnormal growth and the VEGF has a crucial role in inducting tumor angiogenesis, our findings indicate that HBx may play an important role in the processes of HCC by activating IGF-IR and VEGF gene expression.