Effect of hepatitis C virus core shadow protein expressed in human hepatoma cell line on human gene expression profiles

Abstract

The hepatitis C virus (HCV) C region has been reported to have overlapping genes or regions, and may encode a core shadow protein that has a role in HCV self-replication, pathogenesis and carcinogenesis. The aim of this study was to identify the effect of HCV core shadow protein expressed in a human hepatoma (Huh-7) cell line on human gene expression profiles. Recombinants for expression of HCV genotype 1b core shadow protein and genotype 1b core protein were constructed, and an Huh-7 cell line was established that could express the shadow protein and the core protein constitutively. Affymetrix human gene chip, HG-U133 A and B microarray analysis and semiquantitative RT-PCR were employed to identify the expression profiles of two kinds of core proteins in the Huh-7 cell line. The microarray analysis showed that the core shadow protein caused expression of more genes to be up/down-regulation than the core protein, including signal transduction, protease activity, molecular transport and, particularly, immune responses genes. Surprisingly, the core shadow protein could increase/decrease expression of apoptosis and anti-apoptosis genes simultaneously. The expression profiles of three up-regulated genes were confirmed by semiquantitative RT-PCR, with results similar to the microarray analysis. Hepatitis C virus core shadow protein may play an important role in inhibiting or stimulating host cells apoptosis processing and carcinogenesis, which is useful for the understanding of HCV core shadow protein biological functions in vivo and in vitro.