Cellular internalization of a cell-penetrating peptide conjugated gastrin-releasing peptide receptor antagonist

  • Zhengkun Zhong
  • Wentao KanEmail author
  • Wei Liao


This research aims to develop a gastrin-releasing peptide receptor (GRP-R) antagonist that can internalize into the tumor cells by conjugation a cell-penetrating peptide (CPP) to the GRP-R antagonist RM26. Firstly, the side effects of agonist can be avoided. Secondly, cellular internalization allows longer retention in the tumor cells. After the peptides were radiolabeled with 99mTc, cellular uptake and internalization as well as blocking tests were performed to evaluate the cell-penetrating and targeting property of the CPP-conjugated GRP-R antagonist. This study demonstrates the opportunity to modify antagonists with CCPs to enhance their cellular internalization and therapeutic efficacy.


Cell-penetrating GRP-R Antagonist Agonist Internalization Peptide 



This research is financially supported by Science and Technology Development of Foundation of China Academy of Engineering Physics (2014A0301011) and China National Natural Science Foundation (21571164).

Compliance with ethical standards

Conflict of interest

No conflict of interest exits in this research


  1. 1.
    Maecke HR, Reubi JC (2011) Somatostatin receptors as targets for nuclear medicine imaging and radionuclide treatment. J Nucl Med 52:841–844CrossRefGoogle Scholar
  2. 2.
    Schottelius M, Wester HJ (2009) Molecular imaging targeting peptide receptors. Methods 48:161–177CrossRefGoogle Scholar
  3. 3.
    Reubi JC (2003) Peptide receptors as molecular targets for cancer diagnosis and therapy. Endocr Rev 24:389–427CrossRefGoogle Scholar
  4. 4.
    Weiner RE, Thakur ML (2005) Radiolabeled peptides in oncology: role in diagnosis and treatment. Bio Drugs 19:145–163Google Scholar
  5. 5.
    Reubi JC, Maecke HR, Krenning EP (2005) Candidates for peptide receptor radiotherapy today and in the future. J Nucl Med 46:S67–S75Google Scholar
  6. 6.
    Richter S, Wuest M, Krieger SS, Rogers BE, Friebe M, Bergmann R, Wuest F (2013) Synthesis and radiopharmacological evaluation of a high-affinity and metabolically stabilized 18F-labeled bombesin analogue for molecular imaging of gastrin-releasing peptide receptor-expressing prostate cancer. Nucl Med Biol 40:1025–1034CrossRefGoogle Scholar
  7. 7.
    Schröder FH, Roobol MJ (2013) Prostate cancer epidemic in sight? Eur Urol 61:1093–1095CrossRefGoogle Scholar
  8. 8.
    Ambrosini V, Fani M, Fanti S, Forrer F, Maecke HR (2011) Radiopeptide imaging and therapy in Europe. J Nucl Med 52:S42–S55CrossRefGoogle Scholar
  9. 9.
    Mansi R, Wang X, Forrer F, Kneifel S, Tamma ML, Waser B, Cescato R, Reubi JC, Maecke HR (2009) Evaluation of a 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid-conjugated bombesin-based radioantagonist for the labeling with single-photon emission computed tomography, positron emission tomography, and therapeutic radionuclides. Clin Cancer Res 15:5240–5249CrossRefGoogle Scholar
  10. 10.
    Cescato R, Maina T, Nock B, Nikolopoulou A, Charalambidis D, Piccand V, Reubi JC (2008) Bombesin receptor antagonists may be preferable to agonists for tumor targeting. J Nucl Med 49:318–326CrossRefGoogle Scholar
  11. 11.
    Wadas TJ, Eiblmaier M, Zheleznyak A, Sherman CD, Ferdani R, Liang K, Achilefu S, Anderson CJ (2008) Preparation and biological evaluation of 64Cu-CB-TE2A-sst2-ANT, a somatostatin antagonist for PET imaging of somatostatin receptor-positive tumors. J Nucl Med 49:1819–1827CrossRefGoogle Scholar
  12. 12.
    Ginj M, Zhang H, Waser B, Cescato R, Wild D, Wang X, Erchegyi J, Rivier J, Macke HR, Reubi JC (2006) Radiolabeled somatostatin receptor antagonists are preferable to agonists for in vivo peptide receptor targeting of tumors. Proc Natl Acad Sci USA 103:16436–16441CrossRefGoogle Scholar
  13. 13.
    Sancho V, Di Florio A, Moody TW, Jensen RT (2011) Bombesin receptor-mediated imaging and cytotoxicity: review and current status. Curr Drug Deliv 8:79–134CrossRefGoogle Scholar
  14. 14.
    Mansi R, Fleischmann A, Maecke HR, Reubi JC (2013) Targeting GRPR in urological cancers from basic research to clinical application. Nat Rev Urol 10:235–244CrossRefGoogle Scholar
  15. 15.
    Lantry LE, Cappelletti E, Maddalena ME, Fox JS, Feng W, Chen J, Thomas R, Eaton SM, Bogdan NJ, Arunachalam T, Reubi JC, Raju N, Metcalfe EC, Lattuada L, Linder KE, Swenson RE, Tweedle MF, Nunn AD (2006) 177Lu-AMBA: synthesis and characterization of a selective 177Lu-labeled GRP-R agonist for systemic radiotherapy of prostate cancer. J Nucl Med 47:1144–1152Google Scholar
  16. 16.
    Bodei L, Ferrari M, Nunn A, Llull J, Cremonesi M, Martano L, Laurora G, Scardino E, Tiberini S, Bufi G, Eaton S, deCobelli O, Paganelli G (2007) 177Lu-AMBA Bombesin analogue in hormone refractory prostate cancer patients: a phase I escalation study with single-cycle administrations. Eur J Nucl Med Mol Imaging 34:S221Google Scholar
  17. 17.
    Baum RP, Prasad V, Frischknecht M, Maecke HR, Reubi JC (2007) Molecular imaging of bombesin receptors in various tumors by Ga-68 AMBA PET/CT. J Nucl Med 48:79Google Scholar
  18. 18.
    Hoffman TJ, Smith CJ (2009) True radiotracers: Cu-64 targeting vectors based upon bombesin peptide. Nucl Med Biol 36:579–585CrossRefGoogle Scholar
  19. 19.
    Maddalena ME, Fox J, Chen J, Feng W, Cagnolini A, Linder KE, Tweedle MF, Nunn AD, Lantry LE (2009) 177Lu-AMBA biodistribution, radiotherapeutic efficacy, imaging, and autoradiography in prostate cancer models with low GRP-R expression. J Nucl Med 50:2017–2024CrossRefGoogle Scholar
  20. 20.
    Shen MM, Abate-Shen C (2010) Molecular genetics of prostate cancer: new prospects for old challenges. Genes Dev 24:1967–2000CrossRefGoogle Scholar
  21. 21.
    Jamous M, Tamma ML, Gourni E, Waser B, Reubi JC, Maecke HR, Mansi R (2014) PEG spacers of different length influence the biological profile of bombesin-based radiolabeled antagonists. Nucl Med Biol 41:464–470CrossRefGoogle Scholar
  22. 22.
    Mansi R, Wang X, Forrer F, Waser B, Cescato R, Graham K, Borkowski S, Reubi JC, Maecke HR (2011) Development of a potent DOTA-conjugated bombesin antagonist for targeting GRPr-positive tumours. Eur J Nucl Med Mol Imaging 38:97–107CrossRefGoogle Scholar
  23. 23.
    Nock B, Nikolopoulou A, Chiotellis E, Loudos G, Maintas D, Reubi JC, Maina T (2003) Tc-99m demobesin-1, a novel potent bombesin analogue for GRP receptor-targeted tumour imaging. Eur J Nucl Med Mol Imaging 30:247–258CrossRefGoogle Scholar
  24. 24.
    Kroll C, Mansi R, Braun F, Dobitz S, Maecke HR, Wennemers H (2013) Hybrid bombesin analogues: combining an agonist and an antagonist in defined distances for optimized tumor targeting. J Am Chem Soc 135:16793–16796CrossRefGoogle Scholar
  25. 25.
    Oh D, Sun J, Shirazi AN, LaPlante KL, Rowley DC, Parang K (2014) Antibacterial activities of amphiphilic cyclic cell-penetrating peptides against multidrug-resistant pathogens. Mol Pharm 11:3528–3536CrossRefGoogle Scholar
  26. 26.
    Liolios CC, Fragogeorgi EA, Zikos C, Loudos G, Xanthopoulos S, Bouziotis P, Paravatou-Petsotas M, Livaniou E, Varvarigou AD, Sivolapenko GB (2012) Structural modifications of 99mTc-labelled bombesin-like peptides for optimizing pharmacokinetics in prostate tumor targeting. Int J Pharm 430:1–17CrossRefGoogle Scholar
  27. 27.
    Jiang T, Olson ES, Nguyen QT, Roy M, Jennings PA, Tsien RY (2004) Tumor imaging by means of proteolytic activation of cell-penetrating peptides. Proc Natl Acad Sci USA. 101:17867–17872CrossRefGoogle Scholar
  28. 28.
    Vives E (2005) Present and future of cell-penetrating peptide mediated delivery systems: Is the Trojan horse too wild to go only to Troy? J Control Release 109:77–85CrossRefGoogle Scholar
  29. 29.
    Herce HD, Garcia AE (2007) Cell penetrating peptides: How do they do it? J Biol Phys 33:345–356CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2019

Authors and Affiliations

  1. 1.Institute of Nuclear Physics and ChemistryChina Academy of Engineering PhysicsMianyangChina

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