Abstract
The vascular endothelial growth factor (VEGF) receptor is a major target for anti-angiogenesis-based cancer treatment. Here we report the treatment effect of ionizing radiation in combination with the novel orally bioavailable VEGF receptor tyrosine kinase inhibitor PTK787/ZK222584 on endothelial cell proliferation in vitro and with tumour xenografts in vivo. Combined treatment of human umbilical vein endothelial cells with increasing doses of PTK787/ZK222584 and ionizing radiation abrogated VEGF-dependent proliferation in a dose-dependent way, but inhibition of endothelial cell proliferation was not due to apoptosis induction. In vivo, a combined treatment regimen of PTK787/ZK222584 (4 x 100 mg/kg) during 4 consecutive days in combination with ionizing radiation (4 x 3 Gy) exerted a substantial tumour growth delay for radiation-resistant p53-dysfunctional tumour xenografts derived from SW480 colon adenocarcinoma cells while each treatment modality alone had only a minimal effect on tumour size and neovascularization. SW480 tumours from animals that received a combined treatment regimen, displayed not only an extended tumour growth delay but also a significant decrease in the number of microvessels in the tumour xenograft. These results support the model of a cooperative anti-tumoral effect of angiogenesis inhibitor and irradiation and show that the orally bioavailable VEGF receptor tyrosine kinase inhibitor PTK787/ZK222584 is suitable for combination therapy with irradiation.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adenocarcinoma / blood supply
-
Adenocarcinoma / drug therapy*
-
Adenocarcinoma / pathology
-
Adenocarcinoma / radiotherapy
-
Administration, Oral
-
Angiogenesis Inhibitors / administration & dosage
-
Angiogenesis Inhibitors / pharmacology
-
Angiogenesis Inhibitors / therapeutic use*
-
Animals
-
Apoptosis / drug effects
-
Cell Division / drug effects
-
Colonic Neoplasms / blood supply
-
Colonic Neoplasms / drug therapy*
-
Colonic Neoplasms / pathology
-
Colonic Neoplasms / radiotherapy
-
Combined Modality Therapy
-
Endothelium, Vascular / cytology
-
Endothelium, Vascular / drug effects*
-
Endothelium, Vascular / radiation effects
-
Enzyme Inhibitors / administration & dosage
-
Enzyme Inhibitors / pharmacology
-
Enzyme Inhibitors / therapeutic use*
-
Humans
-
Mice
-
Mice, Nude
-
Neoplasm Proteins / antagonists & inhibitors*
-
Neovascularization, Pathologic / drug therapy*
-
Neovascularization, Pathologic / radiotherapy
-
Phthalazines / administration & dosage
-
Phthalazines / pharmacology
-
Phthalazines / therapeutic use*
-
Protein-Tyrosine Kinases / antagonists & inhibitors
-
Pyridines*
-
Radiotherapy, Adjuvant
-
Receptor Protein-Tyrosine Kinases / antagonists & inhibitors*
-
Receptors, Growth Factor / antagonists & inhibitors*
-
Receptors, Vascular Endothelial Growth Factor
-
Xenograft Model Antitumor Assays
Substances
-
Angiogenesis Inhibitors
-
Enzyme Inhibitors
-
Neoplasm Proteins
-
Phthalazines
-
Pyridines
-
Receptors, Growth Factor
-
vatalanib
-
Protein-Tyrosine Kinases
-
Receptor Protein-Tyrosine Kinases
-
Receptors, Vascular Endothelial Growth Factor