The Involvement of PDGF-B/PDGFRβ Axis in the Resistance to Antiangiogenic and Antivascular Therapy in Renal Cancer.

Background/aim: Studies developed in the field of platelet-derived growth factors/platelet-derived growth factor receptors (PDGFs/PDGFRs) inhibition have focused on the therapeutic effects on tumor cells, neglecting their potential effects on tumor blood vessels. We herein propose a differential and critic assessment of platelet-derived growth factor B (PDGF-B) and platelet-derived growth factor receptor β (PDGFRβ) in renal cell carcinoma, correlated with the four main vascular patterns previously reported by our team.

Materials And Methods: PDGF-B and PDGFRβ were evaluated on 50 archival paraffin embedded specimens related to vascular endothelial growth factor (VEGF), its inhibitory isoform VEGF165b and vascular patterns.

Results And Conclusion: Our results support the involvement of VEGF165b in the phosphorylation of PDGFRβ with an inhibitory effect on endothelial proliferation and migration. The simultaneous action of PDGF-B/PDGFRβ and VEGF165b on the same type of receptor may explain the resistance to antiangiogenic therapy, which depends on the degree of modulation of PDGFRβ phosphorylation.