Fig. 3. The reactivation of p53 transcriptional activity by CP-31398 leads to the activation of the Sestrin/AMPK pathway and to the inhibition of mTOR.

a, b CP-31398 treatment of MDA-MB231 cells increases Sestrin-1 and -2 expression at both mRNA (a) and protein (b) levels. c CP-31398 treatment activates AMPK phosphorylation (T172) and decrease phosphorylated m-TOR (S2448) level. d The normalized ratio of Sestrin-1 or -2/Actin, P-AMPK/AMPK, P-mTOR/m-TOR were calculated by densitometry analysis and display (e–f) PFT-α (an inhibitor of p53 transcriptional activity) inhibits CP-31398-induced Sestrin-1 and −2 transcriptional activation (e) and AMPK phosphorylation (T172) (f). Data are representative of three independent experiments (b, c, f) or are the mean ± s.d. of three independent RT-qPCR experiments (a, d, e). The p values (a, e) were determined by unpaired two-tailed Student's t test