FIG. 3.

Expression of Snail or Slug alters the apoptotic response through transcriptional repression of multiple targets. (a) Total RNA was extracted from MCF7 that were infected with Snail, Slug, or mock adenovirus and treated with ADR or vehicle. Steady-state levels of the indicated transcripts were determined by using quantitative RT-PCR. All 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). (b) Simultaneous expression of Snail and Slug does not lead to additive effects on p53 abundance. MCF7 cells were infected with mock, Snail, Slug, or Snail+Slug adenovirus. After 48 h, cells were harvested and protein lysates analyzed by immunoblotting. (c) Snail, Slug, or mock-infected MCF7 were treated with ADR, incubated for the indicated times, and analyzed by immunoblotting with the indicated antibodies. (d and e) Transcript levels for the indicated loci were analyzed as in panel a.