In vivo assessment of aminopeptidase N (APN/CD13) specificity of different 68Ga-labelled NGR derivatives using PET/MRI imaging

Adrienn Kis; Noémi Dénes; Judit P Szabó; Viktória Arató; István Jószai; Kata Nóra Enyedi; Szilvia Lakatos; Ildikó Garai; Gábor Mező; István Kertész; György Trencsényi

doi:10.1016/j.ijpharm.2020.119881

In vivo assessment of aminopeptidase N (APN/CD13) specificity of different ⁶⁸Ga-labelled NGR derivatives using PET/MRI imaging

Int J Pharm. 2020 Nov 15:589:119881. doi: 10.1016/j.ijpharm.2020.119881. Epub 2020 Sep 16.

Authors

Affiliations

¹ Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Hungary; Doctoral School of Clinical Medicine, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary.
² Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Hungary; Gyula Petrányi Doctoral School of Allergy and Clinical Immunology, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary.
³ Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Hungary.
⁴ Eötvös Loránd University, Faculty of Science, Institute of Chemistry, Budapest, Hungary.
⁵ Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Hungary; Scanomed LTD, Nagyerdei St. 98, H-4032 Debrecen, Hungary.
⁶ Eötvös Loránd University, Faculty of Science, Institute of Chemistry, Budapest, Hungary; MTA-ELTE, Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös L. University, Budapest, Hungary.
⁷ Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Hungary; Doctoral School of Clinical Medicine, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary; Gyula Petrányi Doctoral School of Allergy and Clinical Immunology, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary. Electronic address: trencsenyi.gyorgy@med.unideb.hu.

PMID: 32946975
DOI: 10.1016/j.ijpharm.2020.119881

Abstract

Aminopeptidase N (APN/CD13) plays an important role in neoangiogenic process in malignancies. Our previous studies have already shown that ⁶⁸Ga-labelled NOTA conjugated asparagine-glycine-arginine peptide (c[KNGRE]-NH₂) specifically bind to APN/CD13 expressing tumors. The aim of this study was to evaluate and compare the APN/CD13 specificity of newly synthesized ⁶⁸Ga-labelled NGR derivatives in vivo by PET/MRI imaging using hepatocellular carcinoma (He/De) and mesoblastic nephroma (Ne/De) tumor models. PET/MRI and ex vivo biodistribution studies were performed 11 ± 1 days after subcutaneous injection of tumor cells and 90 min after intravenous injection of ⁶⁸Ga-NOTA-c(NGR), ⁶⁸Ga-NODAGA-c(NGR), ⁶⁸Ga-NODAGA-c(NGR) (MG1) or ⁶⁸Ga-NODAGA-c(NGR) (MG2). The APN/CD13 selectivity was confirmed by blocking experiments and the APN/CD13 expression was verified by immunohistochemistry. ⁶⁸Ga-labelled c(NGR) derivatives were produced with high specific activity and radiochemical purity. In control animals, low radiotracer accumulation was found in abdominal and thoracic organs. Using tumor-bearing animals we found that the ⁶⁸Ga-NOTA-c(NGR), ⁶⁸Ga-NODAGA-c(NGR), and ⁶⁸Ga-NODAGA-c(NGR) (MG1) derivatives showed higher uptake in He/De and Ne/De tumors, than that of the accumulation of ⁶⁸Ga-NODAGA-c(NGR) (MG2). APN/CD13 is a very promising target in PET imaging, however, the selection of the appropriate ⁶⁸Ga-labelled NGR-based radiopharmaceutical is critical for the precise detection of tumor neo-angiogenesis and for monitoring the efficacy of anticancer therapy.

Keywords: (68)Ga; Aminopeptidase N; Angiogenesis; CD13; CID: 2796029, 1-hydroxybenzotriazole (HOBt); CID: 3036142, 1,4,7-triazacyclononane-1,4,7-triacetic acid (NOTA); CID: 33032, L-Glutamic acid; CID: 5962, L-Lysine; CID: 6228, N,N-dimethylformamide (DMF); CID: 6267, L-Asparagine; CID: 6322, L-Arginine; CID: 6422, triflouroacetic acid (TFA); CID: 750, Glyicine; NGR; PET/MRI imaging.

MeSH terms

Animals
CD13 Antigens* / metabolism
Cell Line, Tumor
Gallium Radioisotopes
Liver Neoplasms*
Magnetic Resonance Imaging
Male
Positron-Emission Tomography
Tissue Distribution

Substances

Gallium Radioisotopes
CD13 Antigens