Figure 5

The increase in Ad-eIF5A1-induced p53 mRNA levels is dependent upon p53 transcriptional activity. A549 lung carcinoma cells were infected with adenovirus expressing LacZ or eIF5A1 Four hours after infection, the media was replaced with media containing either DMSO, 10 μM of the MEK inhibitor U1026, or 30 μM of the p53 inhibitor pifithrin-α. Forty-eight hours later, total RNA was isolated from the cells and the levels of p53 and TNFR1 mRNA expression were determined by quantitative PCR using GAPDH as a reference gene. Mean expression relative to GAPDH from 3 independent experiments is shown (* p < 0.05; ** p < 0.01).