Figure 6. PDTC-induced activation of AP-1 involves c-jun and c-fos.

(A) Cell extracts (40 μg) from 100 μM PDTC-treated HepG2 cells (2 h) were subjected to SDS/PAGE (10% gels) followed by immunoblot analysis using polyclonal rabbit anti-human c-jun, c-fos and α-actin IgG. (B) Overexpression of c-jun and c-fos increased the transactivation of the AP-1 containing Cp 5′-flanking region. Hep3B cells were transiently transfected with a chimaeric construct containing the proximal 3701 bp of the Cp gene 5′-flanking region driving luciferase in pGL3-basic vectors along with cDNAs of c-jun and c-fos driven by a CMV promoter. All cells were co-transfected with a β-galactosidase plasmid to correct for transfection efficiency. After recovery, the luciferase activity in cell extracts of transfected cells was measured by chemiluminescence and normalized for β-galactosidase activity. Shown are the means±S.D. n=3, **P<0.01 and ***P<0.001.