title: Expression of vascular endothelial growth factor (VEGF) and platelet-derived growth factor receptor-beta (PDGFR-beta) in human gliomas.
abstract: The growth of solid tumors is highly dependent on vascular proliferation. Vascular endothelial growth factor (VEGF), the main mediator of angiogenesis, and platelet-derived growth factor receptor-beta (PDGFR-beta), receptor for the potent mitogen PDGF, are two indicators of the angiogenic potential of human gliomas. We studied a series of 57 surgical biopsies of astrocytic neoplasms by immunohistochemistry to elucidate the relationship between tumor proliferation, quantified as Ki67-LI, and the expression of these two proteins. Ki67-LI increases throughout histological malignancy, although staining in endothelial cells has rarely been recorded. Elevated amounts of VEGF-positive tumor cells (VEGF-LI) were found in anaplastic astrocytomas and glioblastomas, mainly around areas of necrosis, cysts, or edema. Endothelium of blood vessels was consistently stained. PDGFR-beta positivity was found in glomeruloid formations and in tumor cells, excluding pilocytic astrocytomas. Multinucleated giant cells and perivascular tumor cells were positive in glioblastomas. In addition, peritumoral microglia-like cells were also stained in some cases. Statistical correlation was only found between PDGFR-beta and Ki67 LIs. In conclusion, VEGF as permeability factor is involved in the development of secondary neoplastic changes, whereas PDGFR-beta is directly correlated to proliferation indexes. Strong expression of VEGF and PDGFR-beta found in endothelium and tumor cells would seem to support a combined role in tumoral neoangiogenesis.
authors.affiliation: Department of Neurosciences, Basque Country University, Leioa, Spain.
authors.forename: J V
authors.initials: JV
authors.lastname: Lafuente
authors.forename: B
authors.initials: B
authors.lastname: Adán
authors.forename: K
authors.initials: K
authors.lastname: Alkiza
authors.forename: J M
authors.initials: JM
authors.lastname: Garibi
authors.forename: M
authors.initials: M
authors.lastname: Rossi
authors.forename: F F
authors.initials: FF
authors.lastname: Cruz-Sánchez
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016543:Central Nervous System Neoplasms / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D016228:Endothelial Growth Factors / Q000378:metabolism*; D005260:Female; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008222:Lymphokines / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D020797:Receptor, Platelet-Derived Growth Factor beta