FIG. 5.

Depletion of endogenous Snail by using RNAi leads to increased p53 levels and increased sensitivity to apoptotic stimuli. (a) For the left panel, A375 cells were infected with either mock adenovirus or with shRNA-Snail adenovirus; control cells were uninfected. Total RNA was prepared from each cell population and analyzed by RT-PCR with primers for Snail, Slug, and actin as depicted in the figure. For the right panel, Snail depletion was performed by using the shRNA-Snail adenovirus, and lysates were analyzed by immunoblotting. Quantitation of steady-state levels of p53 by densitometry revealed a 1.6-fold increase in p53 levels after depletion of Snail. (b and c) Total RNA was extracted from A375 cells infected with shRNA-Snail or control adenovirus and analyzed by RT-PCR as in panel a. Transcript levels were normalized to actin. All data represent the mean value ± the standard deviation of three independent experiments. ✽, P < 0.05 (as determined by using the Student t test).