Fig. 6
Targeting STAT5 in vivo is therapeutically relevant for ALK+ ALCL. A The tumor volume (mm3) increase of (n = 3) fl/fl Pdgfrb and (n = 3) Δ/Δ Pdgfrb inoculated 6-week old female NSG mice treated with either vehicle or AC-4-130. B Representative macroscopic pictures of excised left and right flank tumors. The right graph represents tumor weight to body weight ratio (%) at the experimental end point. C Representative pictures of the H&E analysis of (n = 3) fl/fl Pdgfrb and (n = 3) Δ/Δ Pdgfrb inoculated 6-week old female NSG mice treated with either vehicle or AC-4-130. The black squares in the left pictures represent the area chosen for the magnification depicted on the right. Scale bars: 50 μm. D Representative pictures of Ki67 and PDGFRβ IHC analysis of (n = 3) fl/fl Pdgfrb and (n = 3) Δ/Δ Pdgfrb inoculated 6-week old female NSG mice treated with either vehicle or AC-4-130. The black squares in the left pictures represent the area chosen for the magnification depicted on the right. Scale bars: 50 μm. Whole-slide scans were quantified using Definiens software (right graphs). E Western blot showing protein levels of phospho (p) STAT3, total STAT3, phospho (p) STAT5 and total STAT5 of end point tumors excised from (n = 3) fl/fl Pdgfrb and (n = 3) Δ/Δ Pdgfrb inoculated 6-week old female NSG mice treated with either vehicle or AC-4-130. GAPDH serves as the loading control. The molecular weight of analyzed proteins in kiloDaltons (KDa) is shown on the left. Phospho (p) STAT3 levels over total STAT3 and phospho (p) STAT5 levels over total STAT5 are depicted as relative volume in %. B, D, and E Data are shown as means ± SD, and p values were determined by an unpaired two-tailed Student’s t-test (multiple t-test application on GraphPad) (ns = p > 0.05; * = p < 0.05; ** = p < 0.01; *** = p < 0.001; **** = p < 0.0001)