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BioMed Research International
Volume 2013, Article ID 420480, 7 pages
http://dx.doi.org/10.1155/2013/420480
Research Article

F-18 Labeled Vasoactive Intestinal Peptide Analogue in the PET Imaging of Colon Carcinoma in Nude Mice

1Department of Nuclear Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China
2Shanghai Institute of Medical Imaging, Shanghai 200032, China
3Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China
4Department of Respiratory Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China

Received 20 October 2013; Revised 29 November 2013; Accepted 29 November 2013

Academic Editor: Weibo Cai

Copyright © 2013 Dengfeng Cheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

As large amount of vasoactive intestinal peptide (VIP) receptors are expressed in various tumors and VIP-related diseases, radiolabeled VIP provides a potential PET imaging agent for VIP receptor. However, structural modification of VIP is required before being radiolabeled and used for VIP receptor imaging due to its poor in vivo stability. As a VIP analogue, [R8, 15, 21, L17]-VIP exhibited improved stability and receptor specificity in preliminary studies. In this study, F-18 labeled [ , L17]-VIP was produced with the radiochemical yield being as high as (decay-for-corrected, ) achieved within 100 min, a specific activity of 255 GBq/μmol, and a radiochemical purity as high as 99% as characterized by radioactive HPLC, TLC, and SDS-Page radioautography. A biodistribution study in normal mice also demonstrated fast elimination of F-18 labeled [ , L17]-VIP in the blood, liver, and gastrointestinal tracts. A further micro-PET imaging study in C26 colon carcinoma bearing mice confirmed the high tumor specificity, with the tumor/muscle radioactivity uptake ratio being as high as 3.03 at 60 min following injection, and no apparent radioactivity concentration in the intestinal tracts. In addition, blocking experiment and Western Blot test further confirmed its potential in PET imaging of VIP receptor-positive tumor.