Molecular Imaging and Biology

, Volume 18, Issue 6, pp 916–923 | Cite as

Synthesis and In Vivo Imaging of N-(3-[11C]Methoxybenzyl)-2-(3-Methoxyphenyl)ethylaniline as a Potential Targeting Agent for P-glycoprotein

  • Debora PetroniEmail author
  • Antonietta Bartoli
  • Simona RapposelliEmail author
  • Maria Digiacomo
  • Silvia Burchielli
  • Giulia Nesi
  • Annalina Lapucci
  • Silvia Pardini
  • Sabrina Fucci
  • Marco Macchia
  • Piero A. Salvadori
  • Luca Menichetti
Research Article



The plasma membrane P-glycoprotein (Pgp) is an efflux transporter involved in multidrug resistance and in the onset of neurodegenerative disease. Its function and most mechanisms of action are still under investigation. We developed a C-11-labeled 2-arylethylphenylamine-([11C]AEPH) derivative for positron emission tomography (PET), as a novel probe to better understand the activity and the function of Pgp in vivo.


The synthetic procedure and the quality control of the selected lead compound, [11C]AEPH-1, were set up and optimized. The biodistribution and the dynamic extraction in target organs of [11C]AEPH-1 were studied in vivo by PET in healthy rats at baseline and after pre-treatment with a Pgp inhibitor (tariquidar).


In vivo dynamic imaging was consistent with the results of ex vivo extraction on explanted organs. An adequate stability for in vivo studies, as well as a high activity of [11C]AEPH-1 in intestine and barrier tissues, has been demonstrated. Results of the blockade study showed a decrease of uptake after the pre-treatment, indicating a behavior attributable to a Pgp ligand.


The suitable pharmacokinetics and the specificity tested in the pre-treated animals have indicated the potentiality of this AEPH derivative to act as Pgp ligand, providing new opportunities for further studies on expression and function of this important efflux transporter in the fields of neurology and oncology.

Key words

P-glycoprotein Multidrug resistance CNS radiotracers [11C]-Methylation Arylethylphenylamine derivatives Arylethylphenoxy derivatives Pgp inhibitor Tariquidar 



This study was partially supported by the grant PRIN2009 (20097FJHPZ_003) from the Ministero dell’Istruzione dell’Università e della Ricerca (MIUR) Italy.

Compliance with Ethical Standards

The experimental protocol, which conformed to the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health (NIH Publication No. 85–23, revised 1996), was approved by the Animal Care Committee of the Italian Ministry of Health (protocol no. 0000249/2014).

Conflict of Interest

The authors declare that they have no conflict of interest.


  1. 1.
    Deeley R, Westlake C, Cole SPC (2006) Transmembrane transport of endo- and xenobiotics by mammalian ATP-binding cassette multidrug resistance proteins. Physiol Rev 86:849–899CrossRefPubMedGoogle Scholar
  2. 2.
    Ambudkar SV, Dey S, Hrycyna AC et al (1999) Biochemical cellular and pharmacological aspects of the multidrug transporter. Annu Rev Pharmacol Toxicol 39:361–398CrossRefPubMedGoogle Scholar
  3. 3.
    Leslie EM, Deeley RG, Cole SP (2005) Multi drug resistance proteins: role of P-glycoprotein, MRP1, MRP2, and BCRP (ABCG2) in tissue defense. Toxicol Appl Pharmacol 204:216–237CrossRefPubMedGoogle Scholar
  4. 4.
    Löscher W, Potschka H (2005) Role of drug efflux transporters in the brain for drug disposition and treatment of brain diseases. Prog Neurobiol 76:22–765CrossRefPubMedGoogle Scholar
  5. 5.
    Higgins CF, Gottesman MM (1992) Is the multidrug transporter a flippase? Trends Biochem Sci 17:18–21CrossRefPubMedGoogle Scholar
  6. 6.
    Sharom FJ (2014) Complex Interplay between the P-glycoprotein multidrug efflux pump and the membrane: its role in modulating protein function. Front Oncol 4(41):1–19Google Scholar
  7. 7.
    Ambudkar SV, Kimchi-Sarfaty C, Sauna ZE et al (2003) P-glycoprotein: from genomics to mechanism. Oncogene 22:7468–7485CrossRefPubMedGoogle Scholar
  8. 8.
    Gottesman MM, Ling V (2006) The molecular basis of multidrug resistance in cancer: the early years of P-glycoprotein research. FEBS Lett 580:998–1009CrossRefPubMedGoogle Scholar
  9. 9.
    Beaulieu E, Demeule M, Ghitescu L et al (1997) P-glycoprotein is strongly expressed in the luminal membranes of the endothelium of blood vessels in the brain. Biochem J 326:539–544CrossRefPubMedPubMedCentralGoogle Scholar
  10. 10.
    Melaine N, Liénard MO, Dorval I et al (2002) Multidrug resistance genes and P-glycoprotein in the testis of the rat, mouse, guinea pig, and human. Biol Reprod 67:1699–1707CrossRefPubMedGoogle Scholar
  11. 11.
    Edwards JE, Alcorn J, Savolainen J et al (2005) Role of P-glycoprotein in distribution of nelfinavir across the blood-mammary tissue barrier and blood-brain barrier. Antimicrob Agents Chemother 49:1626–1628CrossRefPubMedPubMedCentralGoogle Scholar
  12. 12.
    Fromm MF (2004) Importance of P-glycoprotein at blood-tissue barriers. Trends Pharmacol Sci 25:423–429CrossRefPubMedGoogle Scholar
  13. 13.
    Demeule M, Labelle M, Regina A et al (2001) Isolation of endothelial cells from brain, lung, and kidney: expression of the multidrug resistance P-glycoprotein isoforms. Biochem Biophys Res Commun 281:827–834CrossRefPubMedGoogle Scholar
  14. 14.
    Sharom FJ (2008) ABC multidrug transporters: structure, function and role in chemoresistance. Pharmacogenomics 9:105–127CrossRefPubMedGoogle Scholar
  15. 15.
    Meissner K, Sperker B, Karsten C et al (2002) Expression and localization of P-glycoprotein in human heart: effects of cardiomyopathy. J Histochem Cytochem 50(10):1351–1356CrossRefPubMedGoogle Scholar
  16. 16.
    Auzmendi J, Merelli A, Girardi E et al (2014) Progressive heart P-glycoprotein (P-gp) overexpression after experimental repetitive seizures (ERS) associated with fatal status epilepticus (FSE). Is it related with SUDEP? Mol Cell Epilepsy 1:43–51Google Scholar
  17. 17.
    Loscher W, Potschka H (2005) Drug resistance in brain diseases and the role of drug efflux transporters. Nat Rev Neurosci 6:591–602CrossRefPubMedGoogle Scholar
  18. 18.
    Bartels AL, Willemsen ATM, Kortekaas R et al (2008) Decreased blood-brain barrier P-glycoprotein function in the progression of Parkinson’s disease, PSP and MSA. J Neural Transm 115:1001–1009CrossRefPubMedPubMedCentralGoogle Scholar
  19. 19.
    Rapposelli S, Digiacomo M, Balsamo A (2009) P-gp transporter and its role in neurodegenerative diseases. Curr Top Med Chem 9(1):209–217CrossRefPubMedGoogle Scholar
  20. 20.
    Vogelgesang S, Cascorbi I, Schroeder E et al (2002) Deposition of Alzheimer’s beta-amyloid is inversely correlated with P-glycoprotein expression in the brains of elderly non-demented humans. Pharmacogenetics 12(7):535–541CrossRefPubMedGoogle Scholar
  21. 21.
    Van Assema D, Lubberink M, Rizzu P et al (2012) Blood–brain barrier P-glycoprotein function in healthy subjects and Alzheimer’s disease patients: effect of polymorphisms in the ABCB1 gene. EJNMMI Res 2:57CrossRefPubMedPubMedCentralGoogle Scholar
  22. 22.
    Aller SG, Yu J, Ward A et al (2009) Structure of P-glycoprotein reveals a molecular basis for poly-specific drug dinding. Science 323(5922):1718–1722CrossRefPubMedPubMedCentralGoogle Scholar
  23. 23.
    Liu M, Hou T, Feng Z, Li Y (2013) The flexibility of P-glycoprotein for its poly-specific drug binding from molecular dynamics simulations. J Biomol Struct Dyn 31(6):612–629CrossRefPubMedGoogle Scholar
  24. 24.
    Kerb R (2006) Implications of genetic polymorphisms in drug transporters for pharmacotherapy. Cancer Lett 234:4–33CrossRefPubMedGoogle Scholar
  25. 25.
    Syvänen S, Eriksson J (2013) Advances in PET imaging of P-glycoprotein function at the blood-brain barrier. ACS Chem Neurosci 4:225–237CrossRefPubMedGoogle Scholar
  26. 26.
    Hendrikse NH, de Vries EG, Eriks-Fluks L et al (1999) A new in vivo method to study P-glycoprotein transport in tumors and the blood–brain barrier. Cancer Res 59:2411–2416PubMedGoogle Scholar
  27. 27.
    Bart J, Willemsen AT, Groen HJ et al (2003) Quantitative assessment of P-glycoprotein function in the rat blood–brain barrier by distribution volume of [11C]verapamil measured with PET. Neuroimage 20:1775–1782CrossRefPubMedGoogle Scholar
  28. 28.
    Dörner B, Kuntner C, Bankstahl JP et al (2009) Synthesis and small-animal positron emission tomography evaluation of [11C]-elacridar as a radiotracer to assess the distribution of P-glycoprotein at the blood-brain barrier. J Med Chem 52(19):6073–6082CrossRefPubMedPubMedCentralGoogle Scholar
  29. 29.
    Liow JS, Yasuno F et al (2008) 11C-loperamide and its N-desmethyl radiometabolite are avid substrates for brain permeability-glycoprotein efflux. J Nucl Med 49(4):649–656CrossRefPubMedGoogle Scholar
  30. 30.
    Luurtsema G, Schuit RC, Klok RP et al (2009) Evaluation of [11C]laniquidar as a tracer of P-glycoprotein: radiosynthesis and biodistribution in rats. Nucl Med Biol 36(6):643–649CrossRefPubMedGoogle Scholar
  31. 31.
    Lazarova N, Zoghbi SS, Hong J et al (2008) Synthesis and evaluation of [N-methyl-11C]N-desmethyl-loperamide as a new and improved PET radiotracer for imaging P-gp function. J Med Chem 51(19):6034–6043CrossRefPubMedPubMedCentralGoogle Scholar
  32. 32.
    Bauer F, Kuntner C, Bankstahl JP et al (2010) Synthesis and in vivo evaluation of [11C]tariquidar, a positron emission tomography radiotracer based on a third-generation P-glycoprotein inhibitor. Bioorg Med Chem 18(15):5489–5497CrossRefPubMedPubMedCentralGoogle Scholar
  33. 33.
    Levchenko A, Mehta B, Lee J et al (2000) Evaluation of 11C-colchicine for PET imaging of multiple drug resistance. J Nucl Med 41:493–501PubMedGoogle Scholar
  34. 34.
    van Waarde A, Ramakrishnan NK, Rybczynska AA et al (2009) Synthesis and preclinical evaluation of novel PET probes for Pp-glycoprotein function and expression. J Med Chem 52(14):4524–4532CrossRefPubMedGoogle Scholar
  35. 35.
    Shiue CY, Shiue GG, Mozley PD et al (1997) P-[18F]-MPPF: a potential radioligand for PET studies of 5-HT1A receptors in humans. Synapse 25(2):147–154CrossRefPubMedGoogle Scholar
  36. 36.
    Mairinger S, Wanek T, Kuntner C et al (2012) Synthesis and preclinical evaluation of the radiolabeled P-glycoprotein inhibitor [11C]MC113. Nucl Med Biol 39:1219–1225CrossRefPubMedPubMedCentralGoogle Scholar
  37. 37.
    Bart J, Dijkers E, Wegman T et al (2005) New positron emission tomography tracer [11C]carvedilol reveals P-glycoprotein modulation kinetics. Br J Pharmacol 145(8):1045–1051CrossRefPubMedPubMedCentralGoogle Scholar
  38. 38.
    Eriks-Fluks E, Elsinga PH, Hendrikse NH et al (1998) Enzymatic synthesis of [4-methoxy-11C]daunorubicin for functional imaging of P-glycoprotein with PET. Appl Radiat Isot 49(7):811–813CrossRefPubMedGoogle Scholar
  39. 39.
    Luurtsema G, Verbeek J, Lammertsma AA et al (2010) Carbon-11 labeled tracers for in vivo imaging of P-glycoprotein function: kinetics, advantages and disadvantages. Curr Top Med Chem 10:1820–1833CrossRefPubMedGoogle Scholar
  40. 40.
    Colabufo NA, Berardi F, Perrone R et al (2006) Arylmethyloxyphenyl derivatives: small molecules displaying P-glycoprotein inhibition. J Med Chem 49:6607–6613CrossRefPubMedGoogle Scholar
  41. 41.
    Colabufo NA, Berardi F, Perrone R et al (2008) 2-[(3-Methoxyphenylethyl)phenoxy]-based ABCB1 inhibitors: effect of different basic side-chains on their biological properties. J Med Chem 51:7602–7613CrossRefPubMedGoogle Scholar
  42. 42.
    Colabufo NA, Berardi F, Perrone R et al (2008) Synthesis and biological evaluation of (hetero)arylmethyloxy- and arylmethylamine-phenyl derivatives as potent P-glycoprotein modulating agents. J Med Chem 51:1415–1422CrossRefPubMedGoogle Scholar
  43. 43.
    Polli JW, Wring SA, Humphreys JE et al (2001) Huang rational use of in vitro P-glycoprotein assays in drug discovery. J Pharmacol Exp Ther 299:620–628PubMedGoogle Scholar
  44. 44.
    Nesi G, Colabufo NA, Contino M et al (2014) SAR study on arylmethyloxyphenyl scaffold: looking for a P-gp nanomolar affinity. Eur J Med Chem 76:558–566CrossRefPubMedGoogle Scholar
  45. 45.
    Larsen P, Ulin J, Dahlstrom K et al (1997) Synthesis of [11C]iodomethane by iodination of [11C]methane. Appl Radiat Isot 48:153–157CrossRefGoogle Scholar
  46. 46.
    Link JM, Krohn KA, Clark JC (1997) Production of [11C]CH3I by single pass reaction of [11C]CH4 with I2. Nucl Med Biol 24:93–97CrossRefPubMedGoogle Scholar
  47. 47.
    Petroni D, Berton B, Bettini B et al (2014) Performances of a TRACERlab FX C synthesis module using a Ni-nanopowder/molecular sieves mixed catalyst. J Radioanal Nucl Chem 299:2005–2011CrossRefGoogle Scholar
  48. 48.
    Mistry P, Stewart AJ, Dangerfield W et al (2001) In vitro and in vivo reversal of P-glycoprotein-mediated multidrug resistance by a novel potent modulator, XR9576. Cancer Res 61:749–758PubMedGoogle Scholar

Copyright information

© World Molecular Imaging Society 2016

Authors and Affiliations

  • Debora Petroni
    • 1
    Email author
  • Antonietta Bartoli
    • 2
  • Simona Rapposelli
    • 3
    Email author
  • Maria Digiacomo
    • 3
  • Silvia Burchielli
    • 4
  • Giulia Nesi
    • 3
  • Annalina Lapucci
    • 3
  • Silvia Pardini
    • 1
  • Sabrina Fucci
    • 4
  • Marco Macchia
    • 3
  • Piero A. Salvadori
    • 1
  • Luca Menichetti
    • 1
  1. 1.Institute of Clinical PhysiologyConsiglio Nazionale delle Ricerche (CNR)PisaItaly
  2. 2.Molecular Imaging CentreUniversity of TurinIvreaItaly
  3. 3.Department of PharmacyUniversity of PisaPisaItaly
  4. 4.Fondazione Toscana G. MonasterioPisaItaly

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