An antibody directed against PDGF receptor beta enhances the antitumor and the anti-angiogenic activities of an anti-VEGF receptor 2 antibody

Biochem Biophys Res Commun. 2007 Jun 15;357(4):1142-7. doi: 10.1016/j.bbrc.2007.04.075. Epub 2007 Apr 19.

Abstract

Platelet-derived growth factor (PDGF) and its receptors (PDGFR) play important roles in tumorigenesis through stimulating tumor growth and promoting angiogenesis via enhancing pericyte recruitment and vessel maturation. Here we produced a neutralizing antibody, 1B3, directed against mouse PDGFRbeta. 1B3 binds to PDGFRbeta with high affinity (9x10(-11)M) and blocks PDGF-BB from binding to the receptor with an IC(50) of approximately 1.2 nM. The antibody also blocks ligand-stimulated activation of PDGFRbeta and downstream signaling molecules, including Akt and MAPK p42/44, in tumor cells. In animal studies, 1B3 significantly enhanced the antitumor and the anti-angiogenic activities of DC101, an antibody directed against mouse vascular endothelial growth factor receptor 2, in a pancreatic (BxPC-3) and a non-small cell lung (NCI-H460) tumor xenograft models. Treatment with the combination of 1B3 and DC101 in BxPC-3 xenograft-bearing mice resulted in tumor regression in 58% of mice compared to that in 18% of mice treated with DC101 alone. Taken together, these results lend great support to use PDGFRbeta antagonists in combinations with other antitumor and/or anti-angiogenic agents in the treatment of a variety of cancers.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / administration & dosage*
  • Antibodies, Monoclonal / immunology
  • Antineoplastic Agents / administration & dosage
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Humans
  • Neoplasms / blood supply
  • Neoplasms / drug therapy
  • Neoplasms / immunology*
  • Neoplasms / pathology
  • Neovascularization, Pathologic / drug therapy
  • Neovascularization, Pathologic / immunology*
  • Neovascularization, Pathologic / pathology
  • Receptor, Platelet-Derived Growth Factor beta / immunology*
  • Vascular Endothelial Growth Factor Receptor-2 / immunology*

Substances

  • Antibodies, Monoclonal
  • Antineoplastic Agents
  • Receptor, Platelet-Derived Growth Factor beta
  • Vascular Endothelial Growth Factor Receptor-2