Fig. 6

NRP1 inhibition suppresses EGFR and PDGFRα signaling in claudin-low cells. ai Receptor tyrosine kinase array showing EGFR and PDGFRα expression in SUM159 cells after 60 min treatment with 50 μg/mL IgG or Vesencumab (top panel), or 72 h after transfection with NRP1 targeting siRNA (siNRP1 [1] or siNRP1 [2]) versus non-targeting (NT) control (bottom panel), with aii corresponding densitometry. Ref1 and Ref2 represent positive controls. b Western blot showing NRP1, total EGFR, phospho-EGFR (pEGFR Y1068), total PDGFRα and phospho-PDGFRα (Y1018) expression in SUM159, MDA-MB-231 and HS578T cells after 72 h NRP1 knockdown versus NT control. c Correlation analysis between NRP1 and EGFR (right panel; Pearson: 0.24, p = 2.7e−26) and PDGFRα (left panel; Pearson: 0.52, p = 3.47e−130) mRNA expression in the METABRIC dataset (n = 1904) [25]. Data was obtained from cBioportal. d Immunohistochemical analysis of phosphorylated (T202/Y204) p42/44 levels in endpoint (7 weeks post-tumor inoculation) Vesencumab or IgG control treated tumors, with e representative images (right panel); scale bars = 50 µm, n = 5–6. Error bars represent SEM, *p ≤ 0.05; **p ≤ 0.01 versus control