Figure 5.

Inhibition of an IL-6-inducible, STAT-dependent reporter gene. Hep-G₂ cells were cotransfected with 3 μg of 3 X Ly6E GAS-luciferase (39), 1 μg of a β-galactosidase-encoding plasmid, and 11 μg of a control empty vector, or, as indicated, of the same vector containing a CA-MEK cDNA. Cells were split onto replicate plates and after an additional 24 hr, treated for 15 min with PMA followed by a 6-hr stimulation with IL-6. The mean luciferase activity (normalized according to β-galactosidase activity) relative to IL-6-induced activity (set at 100%) is shown. IL-6 induced luciferase activity 20- to 40-fold in these experiments. The results for PMA are based on five independent experiments and for CA-MEK on three independent experiments.