Differential effects of the vascular endothelial growth factor receptor inhibitor PTK787/ZK222584 on tumor angiogenesis and tumor lymphangiogenesis

Mol Cancer Ther. 2009 Jan;8(1):55-63. doi: 10.1158/1535-7163.MCT-08-0679.


Halting tumor growth by interfering with tumor-induced angiogenesis is an attractive therapeutic approach. Such treatments include humanized antibodies blocking the activity of vascular endothelial growth factor (VEGF)-A (bevacizumab), soluble VEGF receptor (VEGFR) constructs (VEGF-Trap), or small-molecule inhibitors of VEGFR signaling, including PTK787/ZK222584 (PTK/ZK), sorafenib, and sunitinib. PTK/ZK has been shown previously to specifically block VEGF-induced phosphorylation of VEGFR-1, -2 and -3 and thereby to inhibit endothelial cell proliferation, differentiation, and tumor angiogenesis. We have investigated the effect of PTK/ZK on tumor angiogenesis and tumor lymphangiogenesis using the Rip1Tag2 transgenic mouse model of pancreatic beta cell carcinogenesis. In Rip1Tag2 mice, tumor angiogenesis is predominantly mediated by VEGF-A, and as expected, PTK/ZK efficiently impaired tumor blood vessel angiogenesis and tumor growth. Double-transgenic Rip1Tag2;Rip1VEGF-C and Rip1Tag2;Rip1VEGF-D mice not only exhibit VEGF-A-dependent blood vessel angiogenesis but also tumor lymphangiogenesis induced by the transgenic expression of VEGF-C or -D. In these mouse models, PTK/ZK also repressed tumor blood vessel angiogenesis and tumor growth yet failed to affect tumor lymphangiogenesis and lymphogenic metastasis. Adenoviral delivery of soluble VEGFR-3 also did not prevent tumor lymphangiogenesis in these mice. In contrast, spontaneous tumor lymphangiogenesis, as observed by the stochastic expression of VEGF-C and -D in tumors of neural cell adhesion molecule-deficient Rip1Tag2 mice, was repressed by PTK/ZK and soluble VEGFR-3. The results indicate that the time of onset and the levels of VEGF-C/D expression may be critical variables in efficiently repressing tumor lymphangiogenesis and that pathways other than VEGFR signaling may be involved in tumor lymphangiogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antineoplastic Agents / therapeutic use
  • Cell Proliferation / drug effects
  • Disease Progression
  • Lymphangiogenesis / drug effects*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Neoplasms / blood supply
  • Neoplasms / drug therapy*
  • Neoplasms / enzymology
  • Neoplasms / pathology*
  • Neovascularization, Pathologic / drug therapy*
  • Phthalazines / therapeutic use*
  • Protein Kinase Inhibitors / therapeutic use*
  • Pyridines / therapeutic use*
  • Receptors, Vascular Endothelial Growth Factor / antagonists & inhibitors*
  • Receptors, Vascular Endothelial Growth Factor / metabolism


  • Antineoplastic Agents
  • Phthalazines
  • Protein Kinase Inhibitors
  • Pyridines
  • vatalanib
  • Receptors, Vascular Endothelial Growth Factor