Next Article in Journal
Compound K Attenuates the Development of Atherosclerosis in ApoE−/− Mice via LXRα Activation
Next Article in Special Issue
Regulation of Translocator Protein 18 kDa (TSPO) Expression in Rat and Human Male Germ Cells
Previous Article in Journal
Dual-Labeled Near-Infrared/99mTc Imaging Probes Using PAMAM-Coated Silica Nanoparticles for the Imaging of HER2-Expressing Cancer Cells
Previous Article in Special Issue
TSPO PIGA Ligands Promote Neurosteroidogenesis and Human Astrocyte Well-Being
Article Menu
Issue 7 (July) cover image

Export Article

Open AccessArticle
Int. J. Mol. Sci. 2016, 17(7), 1085; doi:10.3390/ijms17071085

Synthesis and Evaluation of Tricarbonyl 99mTc-Labeled 2-(4-Chloro)phenyl-imidazo[1,2-a]pyridine Analogs as Novel SPECT Imaging Radiotracer for TSPO-Rich Cancer

1
Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seongnam 13620, Korea
2
Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University, Seoul 16229, Korea
3
Department of Pharmacy–Drug Sciences, University of Bari “Aldo Moro”, Bari 70125, Italy
4
Istituto Tumori IRCCS “Giovanni Paolo II”, Flacco, St. 65, Bari 70124, Italy
5
Department of Chemistry, University of Bari “Aldo Moro”, Bari 70125, Italy
6
Center for Nanomolecular Imaging and Innovative Drug Development, Advanced Institutes of Convergence Technology, Suwon 16229, Korea
*
Authors to whom correspondence should be addressed.
Academic Editor: Mateus Webba da Silva
Received: 4 June 2016 / Revised: 1 July 2016 / Accepted: 1 July 2016 / Published: 7 July 2016
(This article belongs to the Special Issue Translocator Protein (TSPO))
View Full-Text   |   Download PDF [1199 KB, uploaded 7 July 2016]   |  

Abstract

The 18-kDa translocator protein (TSPO) levels are associated with brain, breast, and prostate cancer progression and have emerged as viable targets for cancer therapy and imaging. In order to develop highly selective and active ligands with a high affinity for TSPO, imidazopyridine-based TSPO ligand (CB256, 3) was prepared as the precursor. 99mTc- and Re-CB256 (1 and 2, respectively) were synthesized in high radiochemical yield (74.5% ± 6.4%, decay-corrected, n = 5) and chemical yield (65.6%) by the incorporation of the [99mTc(CO)3(H2O)3]+ and (NEt4)2[Re(CO)3Br3] followed by HPLC separation. Radio-ligand 1 was shown to be stable (>99%) when incubated in human serum for 4 h at 37 °C with a relatively low lipophilicity (logD = 2.15 ± 0.02). The rhenium-185 and -187 complex 2 exhibited a moderate affinity (Ki = 159.3 ± 8.7 nM) for TSPO, whereas its cytotoxicity evaluated on TSPO-rich tumor cell lines was lower than that observed for the precursor. In vitro uptake studies of 1 in C6 and U87-MG cells for 60 min was found to be 9.84% ± 0.17% and 7.87% ± 0.23% ID, respectively. Our results indicated that 99mTc-CB256 can be considered as a potential new TSPO-rich cancer SPECT imaging agent and provides the foundation for further in vivo evaluation. View Full-Text
Keywords: translocator protein; TSPO; Tricarbonyltechnetium-99m; 99mTc(CO)3; TSPO-rich tumors; SPECT translocator protein; TSPO; Tricarbonyltechnetium-99m; 99mTc(CO)3; TSPO-rich tumors; SPECT
Figures

Figure 1

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. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Choi, J.Y.; Iacobazzi, R.M.; Perrone, M.; Margiotta, N.; Cutrignelli, A.; Jung, J.H.; Park, D.D.; Moon, B.S.; Denora, N.; Kim, S.E.; Lee, B.C. Synthesis and Evaluation of Tricarbonyl 99mTc-Labeled 2-(4-Chloro)phenyl-imidazo[1,2-a]pyridine Analogs as Novel SPECT Imaging Radiotracer for TSPO-Rich Cancer. Int. J. Mol. Sci. 2016, 17, 1085.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Int. J. Mol. Sci. EISSN 1422-0067 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top