title: Modeling human tumor angiogenesis in a three-dimensional culture system.
abstract: The intrinsic complexity of the process of vessel formation limits the efficacy of cellular assays for elucidation of its molecular and pharmacologic mechanisms. We developed an ex vivo three-dimensional (3D) assay of sprouting angiogenesis with arterial explants from human umbilical cords. In this assay, human arterial rings were embedded in basement membrane extract gel, leading to a network of capillarylike structures upon vascular endothelial growth factor (VEGF) A stimulation. The angiogenic outgrowth consisted of endothelial cells, which actively internalized acetylated-low-density lipoprotein, surrounded by pericytes. Computer-assisted quantification of this vascular network demonstrated considerable sensitivity of this assay to several angiogenic inhibitors, including kinase inhibitors and monoclonal antibodies. We also performed targeted gene knockdown on this model by directly infecting explanted umbilical arteries with lentiviruses carrying short-hairpin RNA. Downregulation of VEGFR2 resulted in a significant reduction of the sprouting capability, demonstrating the relevance of human vascular explants for functional genomics studies. Furthermore, a modification of this assay led to development of a 3D model of tumor-driven angiogenesis, in which angiogenic outgrowth was sustained by spheroids of prostate cancer cells in absence of exogenous growth factors. The human arterial ring assay bridges the gap between in vitro endothelial cell and animal model, and is a powerful system for identification of genes and drugs that regulate human angiogenesis.
authors.affiliation: Institute for Cancer Research and Treatment at Candiolo, University of Torino, Turin, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Seano
authors.forename: Giulia
authors.initials: G
authors.lastname: Chiaverina
authors.forename: Paolo Armando
authors.initials: PA
authors.lastname: Gagliardi
authors.forename: Laura
authors.initials: L
authors.lastname: di Blasio
authors.forename: Roberto
authors.initials: R
authors.lastname: Sessa
authors.forename: Federico
authors.initials: F
authors.lastname: Bussolino
authors.forename: Luca
authors.initials: L
authors.lastname: Primo
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000166:cytology*; D018929:Cell Culture Techniques / Q000379:methods*; D045744:Cell Line, Tumor; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D016086:Lentivirus / Q000235:genetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000473:pathology* / Q000503:physiopathology*; D011471:Prostatic Neoplasms / Q000098:blood supply / Q000473:pathology*; D014161:Transduction, Genetic / Q000379:methods; D014469:Umbilical Arteries / Q000166:cytology* / Q000502:physiology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics
chemical_list: D020533:Angiogenesis Inhibitors; D040301:Vascular Endothelial Growth Factor Receptor-2