Fig. 2.

Inhibition of WNT secretion by the PORCN inhibitor LGK974 impairs the initiation of HPV-driven cSCC. a Experimental design. Treatment with LGK974 (6 mg/kg) or vehicle was started 7 days prior to tumor induction by UV-irradiation. Mice were treated daily until the end point at day 28. Control mice were treated with vehicle. The vehicle-treated group consisted of four, the LGK974-treated group of five mice. The experiment was performed twice with similar results. b Representative macroscopic display of a vehicle-treated (left panel) and LGK974-treated (middle panel) tumor. Tumor weight at endpoint (right panel). Symbols represent individual mice. c Representative H&E staining of vehicle-treated (left panel) and LGK974-treated (right panel) tumors. Scale bar = 100 µm. d Quantification of transcripts for Pthlh, Ptprz1, and Cd44 in LGK974- and vehicle-treated tumors shows significant reduction of markers for tumor malignancy upon treatment. Symbols represent individual mice. e Representative staining showing stabilization of β-catenin in cytoplasm and nucleus of vehicle-treated tumors, whereas it is mostly membrane associated upon LGK974 treatment (Scale bar = 50 μm). f Representative image of Axin2 in situ hybridization showing reduced transcripts (red) upon LGK974- treatment. Nuclei are counterstained with Hematoxylin. Scale bar = 50 μm. The Porcupine inhibitor LGK974 was applied as described in ref. [31]. In brief, LGK974 was dissolved in DMSO and diluted in citrate buffer pH 3 to a final concentration of 1 mg/ml. Mice were treated daily with 6 mg/kg LGK974 or vehicle (20% DMSO in citrate buffer pH 3) per os. Staining and qPCR Protocols are described in the legend of Fig. 1. The primers used were Pthlh, fwd ATCCCCGACGCCTATGTAA, rev GGGGAAAAAGCAATCAGAGA; Ptprz1, fwd GCCAGTTGTTGTCCACTGC, rev CCTTTGAGAACGAATGTGCTT; Cd44, fwd CTCCTTCTTTATCCGGAGCAC, rev TGGCTTTTTGAGTGCACAGT