Radiolabeling and in vitro and in vivo characterization of [ 18F]FB-[R8,15,21, L17]-VIP as a PET imaging agent for tumor overexpressed VIP receptors

Dengfeng Cheng, Duanzhi Yin, Gucai Li, Mingwei Wang, Shiqiang Li, Mingqiang Zheng, Hancheng Cai, Yongxian Wang

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18 Scopus citations

Abstract

In an effort to develop a peptide-based radiopharmaceutical for the detection of tumors overexpressed vasoactive intestinal peptide receptors with positron emission tomography, we have prepared a novel [R8,15,21, L17]-VIP peptide for 18F-labeling. This peptide inhibited 125I-VIP binding to rats lung membranes with high affinity [half-maximal inhibitory concentrations (IC50) of 0.12 nm]. Additionally, [R8,15,21, L17]-VIP showed higher stability than native vasoactive intestinal peptide in vivo of mice. With N-succinimidyl 4-[18F] fluorobenzoate as labeling prosthetic group, [ 18F]FB-[R8,15,21, L17]-VIP was obtained in >99% radiochemical purity within 100 min in decay-for-corrected radiochemical yield of 33.6 ± 3% (n = 5) and a specific radioactivity 255 GBq/μmol at the end of synthesis. Stability of [18F]FB-[R8,15,21, L17]-VIP in vitro and in vivo were investigated. Biodistribution of this trace was carried out in mice with induced C26 colorectal tumor. Fast clearance of [18F]FB-[R8,15,21, L17]-VIP from non-target tissues and specific uptakes by tumors realized higher tumor-to-muscle ratio (3.55) and tumor-to-blood ratio (2.37) 60 min postinjection. Clear difference was observed between the blocking and unblocking experiments in biodistribution and whole body radioautography. [ 18F]FB-[R8,15,21, L17]-VIP has demonstrated its potential for diagnosing tumors overexpressed vasoactive intestinal peptide receptors both in vitro and in vivo.

Original languageEnglish (US)
Pages (from-to)319-325
Number of pages7
JournalChemical Biology and Drug Design
Volume68
Issue number6
DOIs
StatePublished - Dec 1 2006

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Keywords

  • Colorectal tumor
  • F
  • Imaging
  • Positron emission tomography
  • Radiolabeling
  • Vasoactive intestinal peptide

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Medicine
  • Pharmacology
  • Drug Discovery
  • Organic Chemistry

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