PDGFRα drives tumorigenesis in vivo. (a) BCPAP-derived tumors, with and without PDGFRα in SCID mice. Five mice per group were inoculated with BCPAP mock or BCPAP PDGFRα derived cell lines in Matrigel, results are means ± SEM. (b) Knockdown of the alpha or beta subunits of PDGFR in TPC1 reveal that blockade of the alpha subunit produces the most dramatic decrease in tumor growth. The average tumor volume is shown until sacrifice at day 20. Results are mean ± SEM. (c) 8305C-derived tumors in SCID mice. Five mice per group were inoculated with 8305C mock or shPDGFRα derived cell lines in Matrigel. Results are means ± SEM. (d) Reciprocal relationship between the pattern of PDGFRα and TTF1 staining in tumor xenografts obtained by injecting BCPAP mock and BCPAP PDGFRα cells into SCID mice. Scale bars 400 μm and 50 μm (inset). (e) Effect on sodium iodide transport of crenolanib treatment (0.8 mg/mL) in the SCID xenograft of BCPAP expressing PDGFRα and 8305C cells. Results are means ± SEM, n = 3 independent ex-vivo isolations (f) 8305C-derived tumors in SCID mice. Five mice per group. Animals were treated daily with vehicle (peanut oil) or crenolanib (8 mg/kg), administered daily at 0.8 mg/mL starting 24 h post inoculation until termination (day 19). Results are means ± SEM, n = 3 vehicle, n = 5 crenolanib.