Overexpression of hepatitis B x-interacting protein in HepG2 cells enhances tumor-induced angiogenesis.

Hepatocellular carcinoma (HCC) is a common malignancy and a leading cause of cancer death worldwide. Hepatitis B x-interacting protein (HBXIP), a cofactor of survivin, was originally identified by binding with the C-terminus of the HBx and negatively regulated the activity of HBx. In this study, the effect of HBXIP on the hepatoma cells-induced angiogenesis was investigated. Proliferation and migration of human umbilical vein endothelial cells (HUVECs) were detected by MTT and transwell assay, respectively. Tube formation and chick chorioallantoic membrane model were used to observe the angiogenesis. Vascular endothelial growth factor activity was assayed using ELISA kits. Western blotting was performed to examine the protein expression. Our results indicated that overexpression of HBXIP increased HepG2 cell-induced endothelial cells migration, proliferation, and angiogenesis, which may be related to increasing phosphorylation of endothelial NO synthase in HUVECs. These results suggest that HBXIP may play an important role in tumorigenesis by enhancing angiogenesis in HCC.