Retinoic Acid Causes Up-Regulation of the Gastrointestinal Glutathione Peroxidase (GI-GPx) Promoter and Concomitantly Down-Regulation of Hepatitis C Virus (HCV) Subgenomic RNA

The mRNA expression patterns of three Hepatitis C Virus (HCV)-subgenomic RNA replicon cell lines were compared with those of mock transfected or untransfected HuH7 cells utilizing cDNA array filters. The gastrointestinal-glutathione peroxidase (GI- GPx) mRNA was drastically down-regulated (as low as 5 to 10% of controls) in all replicon cell lines, while the expression level of the classical cellular-glutathione peroxidase (cGPx) remained unaffected. These data were confirmed by Northern blot and Western blot analyses. GI-GPx is a selenoprotein belonging to a family of four members, responsible for the detoxific…