Interferon alpha inhibits the nuclear factor kappa B activation triggered by X gene product of hepatitis B virus in human hepatoma cells.

X gene product of hepatitis B virus (HBV) (HBx) regulates many transcription factors including nuclear factor kappa B (NF-kappaB) and plays a key role in hepatocarcinogenesis. In this study, we demonstrated that the expression of full HBV genome and HBx gene similarly stimulated the transcriptional activity of NF-kappaB in HuH-7 human hepatoma cells, and that interferon (IFN)-alpha as well as dominant negative mutant of IkappaB kinase-alpha effectively inhibited the HBx-mediated NF-kappaB activation, but IFN-gamma did not. These results suggest that IFN-alpha may have a function to block the NF-kappaB activating pathway triggered by HBx in HBV hepatocytes.