(A) Treatment with the Stat3 inhibitor WP1066 decreases proliferation of PtenΔ/Δ; Trp53Δ/Δ primary MEFs compared to DMSO treatment and decreases phosphorylation of Stat3. ANOVA, Dunnett’s post-hoc test, **p<0.01, *p<0.05 vs DMSO, error bars are SD, n=3. (B) Overexpression of dominant negative Stat3DN blocks proliferation of PtenΔ/Δ; Trp53Δ/Δ primary MEFs., dominant negative Stat3DN inhibits the Stat3 transcriptional target Myc. ANOVA, Dunnett’s post-hoc test, **p<0.01, vs GFP at prospective day, error bars are SD, n=3.
(C) JQ1, a Brd4 inhibitor, blocks proliferation of PtenΔ/Δ; Trp53Δ/Δ primary MEFs as measured using crystal violet (upper panel) and Myc expression (bottom panel), Student’s t-Test, ***p < 0.001, error bars are SD, n=3.
(D) short hairpins against Myc decreased proliferation of Pten/Trp53 negative cells and western blot analysis confirm efficient knock-down of Myc and decrease in activation of Stat3/Myc signaling, Pcna western blot confirms decreased proliferation but to less extend than Il6. ANOVA, Dunnett’s post-hoc test, ***p<0.001, vs Ren.713 at prospective day, error bars are SD, n=4.