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Targeting receptors of neurotensin and bombesin

Explore novel radio-ligands targeting neurotensin and bombesin receptors for cancer imaging and therapy, with potential applications in prostate, breast, and other cancers. Investigate ligand-receptor systems and analogs to optimize efficacy.

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Targeting receptors of neurotensin and bombesin

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  1. Targeting receptors of neurotensin and bombesin Franz Buchegger, David Viertl, Thierry Stora, LéoBühler, Helmut R. Maecke, MarekKosinski, SébastienBaechler, Raymond Miralbell, John O. Prior and RosalbaMansi Departments of Nuclear Medicine, Radio-Oncology, Institute of Radiation Physics and Surgical Research Unit, Lausanne and Geneva University Hospitals, European Organization for Nuclear Research, CERN Medicis, Department of Organic Chemistry, VrijeUniversiteit Brussels and Department of Nuclear Medicine, University Hospital of Freiburg CERN Medicis - Oct 2014

  2. Novel radio-ligands in clinicaltumor PET (CHUV) • 68Ga-DOTA-octreotate (collaboration w. SWAN, Bern), neuroendocrine tumors. • 68Ga-NODAGA-RGDyK, targeting avb3integrin, (neovascularization, diverse tumors, atheromatous lesions). • 68Ga-NODAGA-MJ9, bombesin analog with antagonist activity, selected by Prof H.R. Maecke, Freiburg, DE, and Dr R. Mansi, Basel. Study in prostate cancer patients (open) and breast cancer patients (in preparation). • Different Neurotensine analogs conjugated to NODAGA/DOTA chelators are studied in vivo in collaboration with Prof D. Tourwé, Bruxelles.

  3. Neurotensin and bombesin ligand-receptor systems evolved from a common ancestor • The neurotensin and GRP ligand /receptor systems are both G-protein coupled, show similar distributions in the central nervous system and in gastrointestinal tissues and exhibit similar functionalities. • Neurotensin (NT) has been shown to induce EGFR-, c-Src- and Stat5b-dependent proliferation of prostate cancer PC-3, while a commercial NT antagonist SR-48692 (Sanofi Research) tested on the breast cancer cell line MDA-MB-231 inhibited its growth. • SR-48692 is a radiosensitizer (shown on PC-3 tumor grafts). • Bombesin promotes breast cancer cells MDA-MB-231. Bombesin antagonist RC-3095 and RC-3940-II (peptides) inhibit growth of MDA-MB231.

  4. Structural similarities of the G-protein coupled receptors of neurotensin and gastrin releasing peptide (GRP, bombesin) T. Nakagawa et al. Biochem Pharmacol 69 (2005) 579–593 « Structure of the agonist-bound neurotensin receptor ». Jim F. White et al N AT U R E ; V O L 4 9 0 ; 2 5 O C T O B E R 2 0 1 2

  5. We previously performed a SPECT imaging study with 99mTc-tricarbonyl-NT-XI in patients scheduled for surgery of ductal pancreatic adenocarcinoma Tissue activities expressed in %ID/g x104, corrected for physical half-life of isotope. Numbers in parentheses represent tumor-to-normal tissue radioactivity ratios. Buchegger et al, J Nucl Med 2003; 44:1649–1654

  6. Different NT-chelate conjugates have been studied compared here with previously selected 99mTc-labeled peptides of neurotensin 99mTc-NT -XI (NaHis)Ac-Lys-(CH2NH)-Arg-Pro-Tyr-Tle-Leu 99mTc-NT -XIX (NaHis)Ac-Arg-(NMe)Arg-Pro-Dmt-Tle-Leu V Maes, E Garcia-Garayoa, P Bläuenstein and D Tourwé: J. Med. Chem. 2006, 49, 1833-1836 DOTA-NT-XIX DOTA-Arg-(NMe)Arg-Pro-Dmt-Tle-Leu √ NODAGA-NT20.3 Ac-Lys(NODAGA)-Pro-(NMe)Arg-Arg-Pro-Tyr-Tle-Leu √ DOTA-NT20.3 Ac-Lys(DOTA)-Pro-(NMe)Arg-Arg-Pro-Tyr-Tle-Leu √ DOTA-NT20.3- (modified) Ac-Lys(DOTA)-Pro-(NMe)Arg-Arg-Pro-Tyr-Ile-Leu √ NODAGA-PEG-NT-X NODAGA-PEG-Arg-Arg-Pro-Tyr-Tle-Leu √ NODAGA-PEG-NT-X’ NODAGA-PEG-Arg-Arg-Pro-Dmt-Tle-Leu √ NODAGA-PEG-NT-XII NODAGA-PEG-Arg-(NMe)Arg-Pro-Tyr-Tle-Leu √ (NODAGA-PEG-NT-X’’ ) (NODAGA-PEG-Arg-(CH2NH)-Arg-Pro-Tyr-Tle-Leu ) Sequence of natural NT and NT(8-13)Glu-Leu-Tyr-Glu-Asn-Lys-Pro-Arg-Arg-Pro-Tyr-Ile-Leu

  7. 68Ga-NODAGA-NT20.3 Analog to the INSERM : DOTA-NT20.3 (patent) Interesting uptake was observed in reference tumor HT-29and in co-transplanted prostate cancer PC-3 as well as in normal intestines compared with the 99mTc-NT-XIX or the 111In-DOTA-NT20.3 (published by INSERM) and 68Ga-DOTA-NT20.3 (our results)

  8. 68Ga-NODAGA-PEG-NT-X Looked good, has been prepared in GMP quality ! PA= Phosphoramidon (enzyme inhibitor; B.A. Nock et al JNM 2014;55:121-7)

  9. Summary on NT analogs • NODAGA-NT20.3, analog to the French INSERM DOTA-NT20.3 (patented by INSERM) showed good tumor uptake. • NODAGA-PEG-NT-X and derivatives with single further modifications (NT-X’, NT-XII) gave high tumor-to-normal tissue ratios. With 68Ga-NODAGA-PEG-NT-X we have made a preclinical dosimetry and a tolerance study in mice and produced it in GMP quality (ready for a clinical study). • Prostate cancer PC-3 expresses both bombesin and neurotensin receptors in high amount. • Pancreas tumors Capan-2 and Mia-PaCa-2 will be tested as new targets expressing NT receptors (transferred from Douglas Hanahan’s lab). • Glioblastoma lines LN229, U-87, U-251 are other potential targets of neurotensin

  10. Bombesin analogs for imaging (prostate and breast) cancer and preclinical therapy studies • Ligands of gastrin releasing peptide (GRP) have been developed as analogs of bombesin. Bombesin was first isolated from skin of the frog “bombina”. Bombesin is very similar to the human GRP. In human, a strong expression of GRP receptors was found in the central nervous system and neuroendocrin gastrointestinal tissues and cancer, particularly in prostate and breast cancer (studies by Prof. J.C. Reubi, US and Bern). • A comparative PET/CT study on 18F-choline and 11C-acetate has been performed at HUG on 35 patients. A first analysis in 23 patients has been published. It showed a similar behavior of both tracers. • A PET/CT study on evolution of tumor hypoxia under radiation therapy of prostate cancer shown by F-MISO is open at HUG. (comparison with F-Choline or 11C-acétate).

  11.  GRP and GRP receptors and bombesin analogs with agonist and antagonist activity - the similarity with neurotensin • Bombesin is a peptide of 14 amino acids while GRP is composed of 27 amino acids. • GRP receptors (GRPr) and its ligand GRP, are frequently co-expressed by the same cells (autocrine loop), notably in prostate, breast and digestif cancers. • GRPr belongs together with NMBr (neuromedin receptor), BRS-3, NTr1 and NTR2 to the family of G-protein coupled receptors. • The fragment NTS8-13 of neurotensin bound to the receptor NTr1 has been resolved by crystallography. • Similar to NTr1, GRPr has 7 transmembrane domains. The 3 extracellular loops of GRPr form the ligand binding site. GRP and analogs of bombesin exhibiting agonist and antagonist activity: GRP : Val-Pro-Leu-Pro-Ala-Gly-G​ly-Gly-Thr-Val-Leu-Thr-Ly​s-Met-Tyr-Pro-Arg-Gly-Asn​-His-Trp-Ala-Val-Gly-His-​Leu-Met Bombésine :Pyr-Gln-Arg-Leu-Gly-Asn-Gln-Trp-Ala-Val-Gly-His-Leu-Met GRP antagonist : D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu DOTA-RM6 : DOTA-PEG4-(4-amino-1-carboxymethyl-piperidine)-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu NODAGA-MJ9 NODAGA-4-amino-1-carboxymethyl-piperidine-D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu Pyr= pyroglutamyl; Sta=statine

  12. 68Ga-NODAGA-MJ9 (bombesin conjugate) biodistribution1 h after injection of SCID mice bearing PC-3 tumors

  13. 152Tb-DOTA-RM6 in SCID mice bearing PC-3 tumors

  14. 161Tb-DOTA-RM6 Two small PC-3 tumors/mouse (grown over 3 weeks), male SCID mice, DOTA-RM6 as used for Tb-152, 3 mice per group

  15. 68Ga-NODAGA-MJ9 sequential biodistributions(preclinical dosimetry data)

  16. Relative organ contributions to the human effective dose (ED) according to Olinda; The ED predicted from mice was confirmed in 5 male patients with less than 10 % difference. 38.2 mSv/MBq 68Ga-NODAGA-MJ9 dosimetry projection for human application 28.3 mSv/MBq Interval of bladder void : 1 h 0.5 h

  17. 161Tb-DOTA-RM6 (for therapywith SPECT control) 161Tb of PSI(collaboration)

  18. 177Lu-DOTA-RM6 studied under therapy conditions Biodistribution after injection of 8.25 MBq 177Lu-DOTA-RM6 SPECT/CT (clinical imaging device)

  19. 177Lu-DOTA-RM6 pilot therapy studies (PRRT) in combination/comparison with external beam radiation therapy

  20. The CHUV Nuclear Medicine Albira PET/SPECT/CT jointly funded by FNS and UNIL should be operational in 2 to 3 months.

  21. Summary • The clinical study of dual PET/CT foreseen for 60 prostate cancer patients at either initial presentation or recurrence comparing 68Ga-NODAGA-MJ9 with 18F-flurocholine, has confirmed the dosimetry projection extrapolated from mice and is currently generally open for inclusion. • MJ9 exhibiting antagonist activity was predicted not to provoke side effects such as gastrin release or cellular growth. No side effects were observed in our first 8 patients. • DOTA-RM6 can be radiolabeled with positron emitters for PET such as 152Tb or 68Ga, electron emitters for therapy such as 161Tb or 177Lu, or the a-particle emitter 149Tb (the latter co-emitting positrons for PET). DOTA-RM6 radiolabeled with these different radioisotopes should allow approaching therapy studies under well controlled conditions searching for curative approaches. • Our first experiments showed that external beam radiation therapy (RT) combines favorably with systemic radiation therapy with DOTA-bombesin labeled with an electron emitter (PRRT). • Bombesin in conjunction with neurotensin and neurotensin receptor expression of PC-3 cells can allow double receptor targeting with both peptide analogs for a co-operative therapy study (the neurotensin antagonist SR48692 has been shown to be a radiosensitizer on PC-3 tumors (Cancer Research) or could be used as unlabeled growth inhibitor) or to use neurotensin analogs for imaging independent of the therapy with high amounts of bombesin conjugates. Repeat imaging under therapy requires an on-site micro-PET/SPECT/CT. It will be installed at CHUV this month.

  22. Thanks for support to : Fondation pour les recherches médicales et biologiques sur le cancer, Genève. Cellex Foundation, Barcelona (Clinical study support). Dr Catherine Servis, Protein and Peptide Chemistry Facility, Department of Biochemistry, UNIL, for the collaboration in peptide design and production. and a great thanks you for your attention !

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