Design, Synthesis, and Biological Evaluation of the First Radio-Metalated Neurotensin Analogue Targeting Neurotensin Receptor 2

Sacha Bodin; Santo Previti; Emmanuelle Jestin; Delphine Vimont; Imade Ait-Arsa; Frédéric Lamare; Emmanuelle Rémond; Elif Hindié; Florine Cavelier; Clément Morgat

doi:10.1021/acsomega.2c07814

Design, Synthesis, and Biological Evaluation of the First Radio-Metalated Neurotensin Analogue Targeting Neurotensin Receptor 2

ACS Omega. 2023 Feb 10;8(7):6994-7004. doi: 10.1021/acsomega.2c07814. eCollection 2023 Feb 21.

Authors

Sacha Bodin^{1

2}, Santo Previti³, Emmanuelle Jestin⁴, Delphine Vimont², Imade Ait-Arsa⁴, Frédéric Lamare^{1

2}, Emmanuelle Rémond³, Elif Hindié^{1

2

5}, Florine Cavelier³, Clément Morgat^{1

2}

Affiliations

¹ Department of Nuclear Medicine, University Hospital of Bordeaux, 33076 Bordeaux, France.
² University of Bordeaux, CNRS, EPHE, INCIA, UMR 5287, Bordeaux F-33000, France.
³ Institut des Biomolécules Max Mousseron, IBMM, UMR 5247, CNRS, Université de Montpellier, ENSCM, 1919 route de Mende, 34293 Montpellier cedex 5, France.
⁴ Cyclotron Réunion Océan Indien CYROI, 2 rue Maxime Rivière, 97490 Sainte Clotilde, France.
⁵ Institut Universitaire de France, 1 rue Descartes, 75231 Paris, France.

Abstract

Neurotensin receptor 2 (NTS₂) is a well-known mediator of central opioid-independent analgesia. Seminal studies have highlighted NTS₂ overexpression in a variety of tumors including prostate cancer, pancreas adenocarcinoma, and breast cancer. Herein, we describe the first radiometalated neurotensin analogue targeting NTS₂. JMV 7488 (DOTA-(βAla)₂-Lys-Lys-Pro-(D)Trp-Ile-TMSAla-OH) was prepared using solid-phase peptide synthesis, then purified, radiolabeled with ⁶⁸Ga and ¹¹¹In, and investigated in vitro on HT-29 cells and MCF-7 cells, respectively, and in vivo on HT-29 xenografts. [⁶⁸Ga]Ga-JMV 7488 and [¹¹¹In]In-JMV 7488 were quite hydrophilic (logD_7.4 = -3.1 ± 0.2 and -2.7 ± 0.2, respectively, p < 0.0001). Saturation binding studies showed good affinity toward NTS₂ (K _D = 38 ± 17 nM for [⁶⁸Ga]Ga-JMV 7488 on HT-29 and 36 ± 10 nM on MCF-7 cells; K _D = 36 ± 4 nM for [¹¹¹In]In-JMV 7488 on HT-29 and 46 ± 1 nM on MCF-7 cells) and good selectivity (no NTS₁ binding up to 500 nM). On cell-based evaluation, [⁶⁸Ga]Ga-JMV 7488 and [¹¹¹In]In-JMV 7488 showed high and fast NTS₂-mediated internalization of 24 ± 5 and 25 ± 11% at 1 h for [¹¹¹In]In-JMV 7488, respectively, along with low NTS₂-membrane binding (<8%). Efflux was as high as 66 ± 9% at 45 min for [⁶⁸Ga]Ga-JMV 7488 on HT-29 and increased for [¹¹¹In]In-JMV 7488 up to 73 ± 16% on HT-29 and 78 ± 9% on MCF-7 cells at 2 h. Maximum intracellular calcium mobilization of JMV 7488 was 91 ± 11% to that of levocabastine, a known NTS₂ agonist on HT-29 cells demonstrating the agonist behavior of JMV 7488. In nude mice bearing HT-29 xenograft, [⁶⁸Ga]Ga-JMV 7488 showed a moderate but promising significant tumor uptake in biodistribution studies that competes well with other nonmetalated radiotracers targeting NTS₂. Significant uptake was also depicted in lungs. Interestingly, mice prostate also demonstrated [⁶⁸Ga]Ga-JMV 7488 uptake although the mechanism was not NTS₂-mediated.