Combined anti-angiogenic therapy targeting PDGF and VEGF receptors lowers the interstitial fluid pressure in a murine experimental carcinoma

PLoS One. 2009 Dec 4;4(12):e8149. doi: 10.1371/journal.pone.0008149.


Elevation of the interstitial fluid pressure (IFP) of carcinoma is an obstacle in treatment of tumors by chemotherapy and correlates with poor drug uptake. Previous studies have shown that treatment with inhibitors of platelet-derived growth factor (PDGF) or vascular endothelial growth factor (VEGF) signaling lowers the IFP of tumors and improve chemotherapy. In this study, we investigated whether the combination of PDGFR and VEGFR inhibitors could further reduce the IFP of KAT-4 human carcinoma tumors. The tumor IFP was measured using the wick-in-needle technique. The combination of STI571 and PTK/ZK gave an additive effect on the lowering of the IFP of KAT-4 tumors, but the timing of the treatment was crucial. The lowering of IFP following combination therapy was accompanied by vascular remodeling and decreased vascular leakiness. The effects of the inhibitors on the therapeutic efficiency of Taxol were investigated. Whereas the anti-PDGF and anti-VEGF treatment did not significantly inhibit tumor growth, the inhibitors enhanced the effect of chemotherapy. Despite having an additive effect in decreasing tumor IFP, the combination therapy did not further enhance the effect of chemotherapy. Simultaneous targeting of VEGFR and PDGFR kinase activity may be a useful strategy to decrease tumor IFP, but the timing of the inhibitors should be carefully determined.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / pharmacology*
  • Angiogenesis Inhibitors / therapeutic use*
  • Animals
  • Apoptosis / drug effects
  • Blood Volume / drug effects
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Drug Synergism
  • Extracellular Fluid / drug effects*
  • Humans
  • Mice
  • Neoplasms, Experimental / blood supply
  • Neoplasms, Experimental / drug therapy*
  • Neoplasms, Experimental / pathology
  • Neovascularization, Pathologic / drug therapy
  • Neovascularization, Pathologic / pathology
  • Pericytes / drug effects
  • Pericytes / pathology
  • Pressure*
  • Protein Kinase Inhibitors / pharmacology
  • Protein Kinase Inhibitors / therapeutic use
  • Receptors, Platelet-Derived Growth Factor / antagonists & inhibitors*
  • Receptors, Vascular Endothelial Growth Factor / antagonists & inhibitors*


  • Angiogenesis Inhibitors
  • Protein Kinase Inhibitors
  • Receptors, Platelet-Derived Growth Factor
  • Receptors, Vascular Endothelial Growth Factor