Targeting signaling pathways of VEGFR۱ and VEGFR۲ as a potential target in the treatment of breast cancer

Background and Aim: Tumor angiogenesis allows tumor cells to grow and migrate toward the bloodstream and initiate the metastasis process. The interactions of vascular endothelial growth factors (VEGF) A and B, as the important regulating factors for blood vessel growth, with VEGFR۱ and VEGFR۲ trigger angiogenesis process. Thus, preventing these interactions led to the effective blockade of VEGF/VEGFRs signaling pathways.Methods: In this study, the inhibitory effect of a ۲۳-mer linear peptide (VGB۴), which binds to both VEGFR۱ and VEGFR۲, on VEGF-stimulated highly metastatic human breast cancer cell MDA-MB-۲۳۱ proliferation and migration was examined using MTT and wound healing assays. Likewise, to further assess the anti-migratory potential of VGB۴, Human Umbilical Vein Endothelial Cell (HUVEC) wound healing assay was carried out at later time points (۴۸ and ۷۲ h). In addition, downstream signaling pathways of VEGF involved in mediating cell migration and invasion were investigated by quantification of mRNA and protein expression levels using real-time quantitative PCR and western blot in ۴T۱ tumor tissues and MDA-MB-۲۳۱ cells.Results: The results of our work revealed that VGB۴ significantly impeded proliferation and migration of MDA-MB-۲۳۱ cells, in a dose- and time-dependent way, and migration of HUVECs for a prolonged time. A statistically significant reduction of the transcript level of focal adhesion kinase(FAK), Paxillin, matrix metalloproteinase-۲ (MMP-۲), RAS-related C۳ botulinum substrate ۱ (Rac۱), P۲۱-activated kinase-۲ (PAK-۲) and Cofilin-۱ was observed in VGB۴-treated ۴T۱ tumor tissues. The protein level of phospho-VEGFR۱, phospho-VEGFR۲, Vimentin, ?-catenin and Snail was markedly decreased in both VGB۴-treated MDA-MB-۲۳۱ cells and VGB۴-treated ۴T۱ tumor tissues as evidenced by western blotting.Conclusion: The obtained results, plus our previous studies, confirm that dual blockage of VEGFR۱ and VEGFR۲, due to the inactivation of more signaling mediators, has the prominent role in suppressing tumor growth and metastasis.

Keywords:

VEGF , VEGFR۱ , VEGFR۲ , Antagonist peptide , Migration , Metastasis