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Synthesis and biological evaluation of tricarbonyl technetium labeled 2-(4-chloro)phenyl-imidazo[1,2-a]pyridine analog (99mTc-CB257) as a TSPO-binding ligand

  • Choi, Ji Young (Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University) ;
  • Jung, Jae Ho (Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital) ;
  • Song, In Ho (Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital) ;
  • Moon, Byung Seok (Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital) ;
  • Lee, Byung Chul (Department of Nuclear Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital) ;
  • Kim, Sang Eun (Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University)
  • 투고 : 2018.12.12
  • 심사 : 2018.12.21
  • 발행 : 2018.12.30

초록

In our previous study, tricarbonyl $^{99m}Tc$-labeled TSPO-binding ligand, named $^{99m}Tc$-CB256, having positively charge (+1) was investigated but did not show promising results in in vivo environment despite of a nanomolar binding affinity for TSPO. Because the overall positively charge of $^{99m}Tc$-CB256 would likely interrupt its target protein uptake, we herein designed the neutral tricarbonyl-$^{99m}Tc$ labeled TSPO-binding ligand ($^{99m}Tc$-CB257, 1). $^{99m}Tc$-CB257 was prepared by the facile incorporation of the $[^{99m}Tc(CO)_3]^+$ into a N-(hydroxycarbonylmethyl)-2-picoly moiety in CB257. The radiochemical yield of $^{99m}Tc$-CB257 after HPLC purification was $54.1{\pm}2.4%$ (decay corrected, n = 3). The authentic Re-CB257 (2) was synthesized by using $(NEt_4)_2[Re(CO)_3Br_3]$ in 69.0% yield. The binding affinity of 2 for TSPO was measured in leukocyte and showed approximately 280 times higher than that observed for the positively charged (+1) ligand, Re-CB256 ($K_i=0.57{\pm}0.06nM$ versus $159.3{\pm}8.7nM$, respectively). Our results indicated that 1 can be considered potentially as a new SPECT radiotracer for TSPO-rich cancer and provides the foundation for further in vivo evaluation related with abnormal TSPO-overexpression environments.

키워드

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Figure 1. Structure of 99mTc- or Re-CB256 and 99mTc- or Re-CB257

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Scheme 1. Synthesis of CB257 (3), 99mTc- (1) and Re-CB257 (2). Reagents and conditions: a) (i) N-(2-carboxylmethyl)-N-(2-pyridinylmethyl)-1,1-dimethylethylester-glycine, K2CO3, THF, r.t, 16 h, (ii) TFA:CH2Cl2, r.t, 4 h; b) (Net4)2[ReBr3(CO3)], MeOH, 80 ℃, 1 h for 2 and [99mTc(CO)3(H2O)3]+, MeOH:saline (v/v = 1/1), 80 ℃, 20 min for 1.

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Figure 2. Coinjection HPLC profile of 99mTc-CB257 (1) and Re-CB257 (2). (A) gamma-ray spectrum. (B) UV spectrum (254 nm).

Table 1. Affinity (Ki/nM) of 2 for TSPO by using the separated leukocytes in human blooda.

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참고문헌

  1. Papadopoulos V, Baraldi M, Guilarte TR, Knudsen TB, Lacapere JJ, Lindemann P, Norenberg MD, Nutt D, Weizman A, Zhang MR. Translocator protein (18 kDa): New nomenclature for the peripheral-type benzodiazepine receptor based on its structure and molecular function. Trends Pharmacol Sci 2006;27:402-409. https://doi.org/10.1016/j.tips.2006.06.005
  2. Rupprecht R, Papadopoulos V, Rammes G, Baghai TC, Fan J, Akula N, Groyer G, Adams D, Schumacher M. Translocator protein (18 kDa) (TSPO) as a therapeutic target for neurological and psychiatric disorders. Nat Rev Drug Discov 2010;9:971-988. https://doi.org/10.1038/nrd3295
  3. Austin CJD, Kahlert J, Kassiou M, Rendina LM, The translocator protein (TSPO): A novel target for cancer chemotherapy. Int J Biochem Cell Biol 2013;45:1212-1216. https://doi.org/10.1016/j.biocel.2013.03.004
  4. Zheng J, Boisgard R, Siquier-Pernet K, Decaudin D, Dolle F, Tavitian B. Differential expression of the 18 kDa translocator protein (TSPO) by neoplastic and inflammatory cells in mouse tumors of breast cancer. Mol Pharm 2011;8:823-832. https://doi.org/10.1021/mp100433c
  5. Camsonne R, Crouzel C, Comar D, Maziere M, Prenant C, Sastre J, Moulin MA, Syrota A. Synthesis of N-[$^{11}C$]methyl, N-(methyl-1-propyl)(chloro-2-phenyl)-1-isoquinoleinec arboxamide-3 (PK11195): a new ligand for peripheral benzodiazepine receptors. J Labelled Comp Radiopharm 1984;21:985-991. https://doi.org/10.1002/jlcr.2580211012
  6. Shah F, Hume SP, Pike VW, Ashworth S, McDermott J. Synthesis of the enantiomers of [N-methyl-$^{11}C$]PK11195 and comparison of their behaviours as radioligands for PK binding sites in rats. Nucl Med Biol 1994;21:573-581. https://doi.org/10.1016/0969-8051(94)90022-1
  7. Petit-Taboue MC, Baron JC, Barre L, Travere JM, Speckel D, Camsonne R, MacKenzie ET. Brain kinetics and specific binding of [$^{11}C$]PK 11195 to omega 3 sites in baboons: positron emission tomography study. Eur J Pharmacol 1991;200:347-351. https://doi.org/10.1016/0014-2999(91)90594-G
  8. Doorduin J, Klein HC, de Jong JR, Dierckx RA, de Vries EF. Evaluation of [$^{11}C$]DAA1106 for imaging and quantification of neuroinflammation in a rat model of herpes encephalitis. Nucl Med Biol 2010;37:9-15. https://doi.org/10.1016/j.nucmedbio.2009.09.002
  9. Zhang MR, Kida T, Noguchi J, Furutsuka K, Maeda J, Suhara T, Suzuki K. [$^{11}C$]DAA1106: radiosynthesis and in vivo binding to peripheral benzodiazepine receptors in mouse brain. Nucl Med Biol 2003;30:513-519. https://doi.org/10.1016/S0969-8051(03)00016-7
  10. Imaizumi M, Briard E, Zoghbi SS, Gourley JP, Hong J, Fujimura Y, Pike VW, Innis RB, Fujita M. Brain and whole-body imaging in nonhuman primates of [$^{11}C$]PBR28, a promising PET radioligand for peripheral benzodiazepine receptors. NeuroImage 2008;39:1289-1298. https://doi.org/10.1016/j.neuroimage.2007.09.063
  11. Moon BS, Kim BS, Park C, Jung JH, Lee YW, Lee H-Y, Chi DY, Lee BC, Kim SE. [$^{18}F$]Fluoromethyl-PBR28 as a potential radiotracer for TSPO: Preclinical comparison with [$^{11}C$]PBR28 in a rat model of neuroinflammation. Bioconjugate Chem 2014;25:442-450. https://doi.org/10.1021/bc400556h
  12. Perrone M, Moon BS, Park HS, Laquintana V, Jung JH, Cutrignelli A, Lopedota A, Franco M, Kim SE, Lee BC, Denora N. A novel PET imaging probe for the detection and monitoring of translocator protein 18 kDa expression in pathological disorders. Sci Rep 2016;6:20422. https://doi.org/10.1038/srep20422
  13. Le Fur G, Perrier ML, Vaucher N, Imbault F, Flamier A, Benavides J, Uzan A, Renault C, Dubroeucq MC, Gueremy C. Peripheral benzodiazepine binding sites: Effect of PK11195, 1-(2-chlorophenyl)-N-(1-methylpropyl)-3-isoquinolinecarboxamide I. In vitro studies. Life Sci 1983;32:1839-1847. https://doi.org/10.1016/0024-3205(83)90062-0
  14. Imaizumi M, Briard E, Zoghbi SS, Gourley JP, Hong J, Fujimura Y, Pike VW, Innis RB, Fujita M. Brain and whole-body imaging in nonhuman primates of [$^{11}C$] PBR28, a promising PET radioligand for peripheral benzodiazepine receptors. NeuroImage 2008;39:1289-1298. https://doi.org/10.1016/j.neuroimage.2007.09.063
  15. Schibli R, Netter M, Scapozza L, Birringer M, Schelling P, Dumas C, Schoch J, Schubiger PA. First organometallic inhibitors for human thymidine kinase: Synthesis and in vitro evaluation of rhenium(I)- and technetium(I)-tricarbonyl complexes of thymidine. J Organomet Chem 2003;668:67-74. https://doi.org/10.1016/S0022-328X(02)02100-9
  16. Lee BC, Kim DH, Lee JH, Sung HJ, Choe YS, Chi DY, Lee KH, Choi Y, Kim BT. $^{99m}Tc(CO)_3$-15-[N-(Acetyloxy)-2-picolylamino]pentadecanoic acid: A potential radiotracer for evaluation of fatty acid metabolism. Bioconjug Chem 2007;18:1332-1337. https://doi.org/10.1021/bc060299w
  17. Denora N, Margiotta N, Laquintana V, Lopedota A, Cutrignelli A, Losacco M, Franco M, Natile G. Synthesis, characterization, and in vitro evaluation of a new TSPO selective bifunctional chelate ligand. ACS Med Chem Lett 2014;5:685-689. https://doi.org/10.1021/ml5000788
  18. Margiotta N, Denora N, Piccinonna S, Laquintana V, Lasorsa FM, Franco M, Natile G. Synthesis, characterization, and in vitro evaluation of new coordination complexes of platinum(II) and rhenium(I) with a ligand targeting the translocator protein (TSPO). Dalton Trans 2014;43:16252-16264. https://doi.org/10.1039/C4DT01540A
  19. Choi JY, Iacobazzi RM, Perrone M, Margiotta N, Cutrignelli A, Jung JH, Park DD, Moon BS, Denora N, Kim SE, Lee BC. Synthesis and evaluation of tricarbonyl $^{99m}Tc$-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;7:1085
  20. Schottelius M, Rau F, Reubi JC, Schwaiger M, Wester HJ. Modulation of pharmacokinetics of radioiodinated sugar-conjugated somatostatin analogues by variation of peptide net charge and carbohydration chemistry. Bioconjugate Chem 2005;16:429-437. https://doi.org/10.1021/bc0499228
  21. Alberto R, Schibli R, Egli A, Schubiger AP. A novel organometallic aqua complex of technetium for the labeling of biomolecules: Synthesis of $[^{99m}Tc(OH_2)_3(CO)_3]^+$ from [$^{99m}TcO^4$]- in aqueous solution and its reaction with a bifunctional ligand. J Am Chem Soc 1998;120:7987-7988. https://doi.org/10.1021/ja980745t
  22. Schibli R, Katti KV, Volkert WA, Barnes CL. Novel coordination behavior of fac-$[ReBr_3(CO)_3]^2$-with 1,3,5-triaza-7-phosphaadamantane (PTA). Systematic investigation on stepwise replacement of the halides by PTA ligand. Phase transfer studies and X-ray crystal structure of $[NEt_4][ReBr_2((PTA)(CO)_3]$, $[ReBr(PTA)_2(CO)_3]$, and $[Re(PTA)_3(CO)_3]PF_6$. Inorg. Chem. 1998;37:5306-5312. https://doi.org/10.1021/ic980373p