title: Differential Receptor Binding and Regulatory Mechanisms for the Lymphangiogenic Growth Factors Vascular Endothelial Growth Factor (VEGF)-C and -D.
abstract: VEGF-C and VEGF-D are secreted glycoproteins that induce angiogenesis and lymphangiogenesis in cancer, thereby promoting tumor growth and spread. They exhibit structural homology and activate VEGFR-2 and VEGFR-3, receptors on endothelial cells that signal for growth of blood vessels and lymphatics. VEGF-C and VEGF-D were thought to exhibit similar bioactivities, yet recent studies indicated distinct signaling mechanisms (e.g. tumor-derived VEGF-C promoted expression of the prostaglandin biosynthetic enzyme COX-2 in lymphatics, a response thought to facilitate metastasis via the lymphatic vasculature, whereas VEGF-D did not). Here we explore the basis of the distinct bioactivities of VEGF-D using a neutralizing antibody, peptide mapping, and mutagenesis to demonstrate that the N-terminal α-helix of mature VEGF-D (Phe93-Arg108) is critical for binding VEGFR-2 and VEGFR-3. Importantly, the N-terminal part of this α-helix, from Phe93to Thr98, is required for binding VEGFR-3 but not VEGFR-2. Surprisingly, the corresponding part of the α-helix in mature VEGF-C did not influence binding to either VEGFR-2 or VEGFR-3, indicating distinct determinants of receptor binding by these growth factors. A variant of mature VEGF-D harboring a mutation in the N-terminal α-helix, D103A, exhibited enhanced potency for activating VEGFR-3, was able to promote increased COX-2 mRNA levels in lymphatic endothelial cells, and had enhanced capacity to induce lymphatic sprouting in vivo This mutant may be useful for developing protein-based therapeutics to drive lymphangiogenesis in clinical settings, such as lymphedema. Our studies shed light on the VEGF-D structure/function relationship and provide a basis for understanding functional differences compared with VEGF-C.
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000.
authors.forename: Natalia
authors.initials: N
authors.lastname: Davydova
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000.
authors.forename: Nicole C
authors.initials: NC
authors.lastname: Harris
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000.
authors.forename: Sally
authors.initials: S
authors.lastname: Roufail
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000.
authors.forename: Sophie
authors.initials: S
authors.lastname: Paquet-Fifield
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000.
authors.forename: Musarat
authors.initials: M
authors.lastname: Ishaq
authors.affiliation: the Florey Institute of Neuroscience and Mental Health, 30 Royal Parade, Parkville, Victoria 3052, and.
authors.forename: Victor A
authors.initials: VA
authors.lastname: Streltsov
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Williams
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000.
authors.forename: Tara
authors.initials: T
authors.lastname: Karnezis
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000.|the Sir Peter MacCallum Department of Oncology, University of Melbourne, Victoria 3010, Australia.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Stacker
authors.affiliation: From the Tumour Angiogenesis and Microenvironment Program, Peter MacCallum Cancer Centre, Melbourne, Victoria 3000, marc.achen@petermac.org.|the Sir Peter MacCallum Department of Oncology, University of Melbourne, Victoria 3010, Australia.
authors.forename: Marc G
authors.initials: MG
authors.lastname: Achen
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing; D002478:Cells, Cultured; D020405:Dermis / Q000378:metabolism / Q000473:pathology; D004730:Endothelium, Vascular / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D042583:Lymphangiogenesis; D042601:Lymphatic Vessels / Q000378:metabolism / Q000473:pathology*; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D009389:Neovascularization, Pathologic / Q000378:metabolism / Q000473:pathology*; D015398:Signal Transduction; D042582:Vascular Endothelial Growth Factor C / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D042643:Vascular Endothelial Growth Factor D / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism*; D040321:Vascular Endothelial Growth Factor Receptor-3 / Q000235:genetics / Q000378:metabolism*
chemical_list: D057134:Antibodies, Neutralizing; C467486:VEGFC protein, human; C579459:VEGFD protein, human; D042582:Vascular Endothelial Growth Factor C; D042643:Vascular Endothelial Growth Factor D; D040301:Vascular Endothelial Growth Factor Receptor-2; D040321:Vascular Endothelial Growth Factor Receptor-3
keywords: angiogenesis; endothelial cell; lymphangiogenesis; mutagenesis in vitro; receptor; vascular endothelial growth factor (VEGF)