title: The RNA aptamer inhibiting human vesicular endothelial growth factor receptor 1 without affecting cytokine binding.
abstract: Angiogenesis, a process of new blood vessel formation, is crucial not only for many physiological events but also for a number of diseases. The signaling pathways through members of the vesicular endothelial growth factor (VEGF) family play fundamental roles in angiogenesis. In this study, we identified inhibitory RNA aptamers against human Flt-1, a receptor of VEGF. One of the isolates, aptamer #38, showed a 50% inhibitory concentration (IC50) of 23 nM in the cell-based autophosphorylation assay, and the IC50 value was decreased to 6.3 nM upon removal of 32 dispensable nucleotides from parental #38 with a length of 72 nucleotides. Interestingly, the surface plasmon resonance-based or affinity resin-based binding study revealed that #38 and its shortened derivative, #38Jr, do not interfere with binding of VEGF or heparin, a functional cofactor, to Flt-1. Importantly, aptamer #38 does not affect the decoy activity of soluble Flt-1. These findings suggest that #38 prevents the conformational activation of Flt-1 associated with VEGF. Therefore, aptamer #38 might provide us with a unique tool for blocking the VEGF signaling specific to Flt-1, unlike most other known VEGF signaling blockers such as VEGF inhibitors, anti-Flt-1 antibodies, and decoy soluble receptors.
authors: Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
authors: Shoji P
authors: SP
authors: Ohuchi
authors: Masabumi
authors: M
authors: Shibuya
authors: Yoshikazu
authors: Y
authors: Nakamura
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology*; D001483:Base Sequence; D016207:Cytokines / Q000378:metabolism; D006493:Heparin / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D009154:Mutation; D011485:Protein Binding / Q000187:drug effects; D052156:SELEX Aptamer Technique; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040281:Vascular Endothelial Growth Factor Receptor-1 / Q000037:antagonists & inhibitors* / Q000378:metabolism*
chemical_list: D052157:Aptamers, Nucleotide; D016207:Cytokines; D042461:Vascular Endothelial Growth Factor A; D006493:Heparin; C501162:FLT1 protein, human; D040281:Vascular Endothelial Growth Factor Receptor-1