FIG. 4.

Transient transfection of Huh7 cells with Rz3′X or PSMA7-directed ribozymes and bicistronic reporter plasmids expressing FL dependent on HCV, EMCV, or HRV IRES. (A) PSMA7-directed ribozymes VRz1 to -4, Rz3′X, and control RzBR1 were cotransfected into Huh7 cells with a bicistronic reporter construct (RL-5′-CFL), allowing for cap-dependent translation of the RL gene, followed by the HCV 5′UTR for IRES-mediated translation of the HCV core protein and FL gene. Luciferase activities were measured by dual-luciferase assay, and the FL/RL ratio detected in RzBR1-transfected cells was set to 100%. (B) Rz3′X, PSMA7-directed ribozymes VRz2 and -3, and control RzBR1 were cotransfected into Huh7 cells with bicistronic reporter construct RL-HCV-FL (HCV 5′ UTR, allowing for IRES-mediated translation of the FL gene), RL-EMCV-FL, or RL-HRV-FL. Changes in IRES activities (FL/RL ratios) from triplicate experiments are expressed relative to the activity of the RzBR1 control and are presented as means ± standard errors of the means.