title: Site-specifically biotinylated VEGF(121) for near-infrared fluorescence imaging of tumor angiogenesis.
abstract: The vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) pathway is considered to be one of the most important regulators of angiogenesis and a key target in anticancer treatment. Imaging VEGFR expression can serve as a new paradigm for assessing the efficacy of antiangiogenic cancer therapy, improving cancer management, and elucidating the role and modulation of VEGF/VEGFR signaling during cancer development and intervention. In this study we developed an Avi-tagged VEGF(121) protein, which is site-specifically biotinylated in the presence of bacterial BirA biotin ligase. BirA biotinylated VEGF(121)-Avi (VEGF(121)-Avib) forms a stable complex with streptavidin-IRDye800 (SA800) that retains high affinity for VEGFR in vitro and allows receptor specific targeting in vivo in a 67NR murine xenograft model. In contrast, chemical coupling of IRDye800 abrogated the VEGFR binding ability of the modified protein both in vitro and in vivo. The VEGF(121)-Avib/SA800 complex (VEGF-Avib/SA800) may be used for quantitative and repetitive near-infrared fluorescence imaging of VEGFR expression and translated into clinic for evaluating cancer and other angiogenesis related diseases.
authors.affiliation: Department of Radiology, Stanford University School of Medicine, Stanford, California 94305-5484, USA.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Chen
authors.forename: Gang
authors.initials: G
authors.lastname: Niu
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Chen
mesh_terms: D000818:Animals; D001710:Biotin / Q000737:chemistry*; D002460:Cell Line; D006801:Humans; D008856:Microscopy, Fluorescence; D009369:Neoplasms / Q000098:blood supply* / Q000737:chemistry / Q000378:metabolism*; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D013055:Spectrophotometry, Infrared; D013379:Substrate Specificity; D013552:Swine; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D042461:Vascular Endothelial Growth Factor A; D001710:Biotin