FIG. 1.

Effect of IRNA on HCV IRES-mediated translation in Huh-7 cells. Monolayer cells (10⁶) were transfected with three different plasmid DNAs: pCDIR.Ribo.ΔT7 expressing IRNA, pCD HCV-luc reporter plasmid in which luciferase translation is programmed by the HCV IRES, and a β-Gal reporter gene to measure transfection efficiency. After 24 h of transfection, extracts were made and luciferase and β-Gal activities were measured. Luciferase activity (light units) is expressed as percentage of the control after normalizing for β-Gal activity and protein content for each transformation. (A) Vertical bars 1, 2, and 3 show the dose-response effect of pCDIR.Ribo.ΔT7 on HCV IRES-mediated translation of luciferase gene at 0, 1.25, and 1.88 μg of pCDIR.Ribo.ΔT7, respectively. Total DNA concentration was made up to 2.5 μg by adding 2.5, 1.25, and 0.62 μg of pCDNA3 (bars 1, 2, and 3, respectively). (B) A similar experiment was performed in which plasmid pCD HCV-luc was replaced by pCDNA3-luc conferring cap-dependent translation of luciferase. All transfection reactions contained 1 μg each of β-Gal and luciferase reporter plasmids.