Fig. 2.

p53 mediates HCV NS5A-induced downregulation of GADD45α expression. Stable vector-Huh7, NS5A-Huh7 and Huh7-2-3 cells were seeded into a 24-well plate 24 h before transfection with a p53 plasmid (0.5 µg) or p53 siRNA (50 nM) for 72 h. (a) Quantitative PCR for p53 mRNA levels. *P<0.05. (b) Quantitative PCR for GADD45α mRNA expression in the presence of p53 overexpression (p53) or knockdown (p53 siRNA). **P<0.001. Results for (a) and (b) are shown as means±sem of three independent experiments. (c) Representative Western blotting for p53, GADD45α, NS5A and β-actin protein levels. p53 protein was knocked down by p53 siRNAs (lanes 7–9). NS5A protein was detected in NS5A-Huh7 (lanes 2, 5 and 8) and Huh7-2-3 cells (lanes 3, 6 and 9).