Fig. 1. Expression of stabilized ETV4 (ETV4^AAA) induces prevalent mPin.

(A) Schematic for generating mice with transgenic expression of human ETV4^WT and ETV4^AAA driven by the chicken actin CMV composite promoter (CAG) knocked into the mouse Rosa26 locus. The targeting plasmid was electrophoresed into albino C57BL/6J embryonic stem cells to generate the Rosa26-CAG-LSL-ETV4^WT and Rosa26-CAG-LSL-ETV4^AAA mice. (B) ETV4 protein expression in mouse prostate from two mice of each genotype quantified by Western blot 1 week after tamoxifen (TAM) treatment. The intensity of ETV4 bands is quantified using ImageJ. GAPDH, glyceraldehyde-3-phosphate dehydrogenase. (C and D) Two weeks (C) and 12 months (D) after TAM treatment, histological analysis anterior prostate of T2; EYFP, T2; ETV4^WT, and T2; ETV4^AAA mice prostate is shown by hematoxylin and eosin (H&E). The expression of EGFP, ETV4, AR, and Ki67 are analyzed with immunohistochemistry (IHC) staining. Scale bars, 50 μm. (E) The Ki67-positive luminal cell ratios are quantified on IHC stained slides. (F) IHC staining of ETV4 on MDA PCa patient-derived xenograft (PDX) samples. Error bars are SD.