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Contrast Media & Molecular Imaging
Volume 2017, Article ID 2674502, 8 pages
https://doi.org/10.1155/2017/2674502
Research Article

PET Imaging of FSHR Expression in Tumors with 68Ga-Labeled FSH1 Peptide

1Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, Jiangsu 214063, China
2Department of Radiology, China-Japan Union Hospital of Jilin University, Changchun, Jilin 130033, China
3Nanjing Medical University, Nanjing, Jiangsu 210029, China
4Zhengzhou University, Zhengzhou, Henan 450001, China

Correspondence should be addressed to Min Yang; gro.mnisj@nimgnay

Received 29 March 2017; Revised 7 July 2017; Accepted 25 July 2017; Published 23 August 2017

Academic Editor: Shengxian Rao

Copyright © 2017 Donghui Pan 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

FSHR is an appealing target for cancer theranostics. Radiolabeled FSH1 and its derivatives have shown potential to in vivo detect FSHR expression. However, moderate labeling yields (~50% nondecay-corrected) may partially limit their wide use. 68Ga is an excellent PET nuclide due to availability, nearly quantitative reaction, and short physical half-life. In this study, 68Ga labeled FSH1 peptide was developed for imaging of FSHR in cancers. In vitro studies and MicroPET imaging were performed in PC-3 prostate tumor model. [68Ga] Ga-NOTA-MAL-FSH1 can be produced within 20 min with yield and the radiochemical purity was greater than 95%. It showed that [68Ga] Ga-NOTA-MAL-FSH1 possessed FSHR binding affinities. The tracer was stable in PBS and human serum for at least 2 hours. MicroPET imaging revealed that the PC-3 xenografts were clearly visualized and the tumor uptakes were , , and % ID/g at 0.5, 1 h, and 2 h postinjection. The corresponding tumor to blood and tumor to muscle ratios were , , and and , , and , respectively. FSHR binding specificity was also demonstrated by reduced tumor uptake of [68Ga] Ga-NOTA-MAL-FSH1 after coinjecting excess unlabeled FSH1 peptide. The favorable characters of [68Ga] Ga-NOTA-MAL-FSH1 such as convenient synthesis and specific tumor uptake warrant its further investigation for FSHR expression imaging.