Skip to main content
. 2008 Nov;19(11):4875–4887. doi: 10.1091/mbc.E08-05-0506

Figure 5.

Figure 5.

TGF-β1 or TGF-β2 initiates this Snail- or Slug-induced signaling cascade to promote EMT. (A) TGF-β1 and TGF-β2 caused up-regulations of Snail and Slug as observed by immunoblotting. Addition of a MEK1/2 inhibitor (U0126) prevented these up-regulations. (B) Real-time quantitative PCR showing that LEF-1 expression was increased upon treatment of cells with TGF-β1 or TGF-β2 but was prevented by the addition of Snail siRNA and/or Slug siRNA. Data represent mean±SD; n=3; *p<0.001 compared with control; **p<0.001 compared with TGF-B1 or TGF-B2. (C) Immunoblotting for LEF-1 protein expression showing that TGF-β1 or TGF-β2 causes increased levels, but in the presence of a TGF-β3 neutralizing antibody (TGF-β3 Ab), LEF-1 expression was greatly reduced. (D) Time course-dependent p3TP-Lux luciferase assay showing that TGF-β/Smad activity increased through 12 h posttreatment with either TGF-β1 or TGF-β2. Reporter activity was then reduced by 24 h followed by continuous increases through 72 h as a result of endogenous expression of TGF-β3, because a TGF-β3 neutralizing antibody (TGF-β3 Ab) prevented the second wave of transcriptional activity. Data represent mean±SD; n=3; *p<0.05 compared with 0 h; **p<0.0001 compared with TGF-B1 or TGF-B2.