Human melanoma cells but not normal melanocytes express vascular endothelial growth factor receptors.
Vascular endothelial growth factor (VEGF) is a specific mitogen for endothelial cells in vitro and an angiogenic factor in vivo. Its role in other cell types is not yet clear. To explore its possible involvement in malignant transformation, we studied the expression of its receptors in normal and malignant melanocytes. Binding and cross-linking experiments showed that human melanoma cells but not normal melanocytes express VEGF receptors. Separation of reaction products by SDS-PAGE demonstrated the presence of 125I-VEGF/receptor complexes of 180 and 165 kDa in the melanoma cells. A diffuse complex with a mass of approximately 235 kDa was also detected in some experiments. Heparin enhanced the binding of the radioactive ligand to the receptors of the WW94 and SW1614 melanoma cell lines. This binding was completely abolished by heparinase digestion and was restored by the addition of exogenous heparin, indicating that heparin-like molecules are necessary for ligand/receptor interaction. This study suggests that the aberrant expression of VEGF receptors is one of the phenotypic changes occurring in melanoma cells during malignant transformation.
Gitay-Goren
H
H
Department of Biology, Technion, Israel Institute of Technology, Technion City, Haifa.
Halaban
R
R
Neufeld
G
G
D002478:Cells, Cultured; D003432:Cross-Linking Reagents; D016228:Endothelial Growth Factors / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D008222:Lymphokines / Q000378:metabolism*; D008544:Melanocytes / Q000378:metabolism*; D008545:Melanoma / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011975:Receptors, Mitogen / Q000378:metabolism*; D040262:Receptors, Vascular Endothelial Growth Factor; D011994:Recombinant Proteins / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D003432:Cross-Linking Reagents; D016228:Endothelial Growth Factors; D008222:Lymphokines; D011975:Receptors, Mitogen; D011994:Recombinant Proteins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D006493:Heparin; D011505:Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor