In Vivo Molecular Imaging of the Efficacy of Aminopeptidase N (APN/CD13) Receptor Inhibitor Treatment on Experimental Tumors Using 68Ga-NODAGA-c(NGR) Peptide

Adrienn Kis; Noémi Dénes; Judit P Szabó; Viktória Arató; Lívia Beke; Orsolya Matolay; Kata Nóra Enyedi; Gábor Méhes; Gábor Mező; Péter Bai; István Kertész; György Trencsényi

doi:10.1155/2021/6642973

In Vivo Molecular Imaging of the Efficacy of Aminopeptidase N (APN/CD13) Receptor Inhibitor Treatment on Experimental Tumors Using ⁶⁸Ga-NODAGA-c(NGR) Peptide

Biomed Res Int. 2021 Mar 10:2021:6642973. doi: 10.1155/2021/6642973. eCollection 2021.

Authors

Adrienn Kis^{1

2}, Noémi Dénes^{1

3}, Judit P Szabó^{1

2}, Viktória Arató¹, Lívia Beke⁴, Orsolya Matolay⁴, Kata Nóra Enyedi⁵, Gábor Méhes⁴, Gábor Mező^{5

6}, Péter Bai^{7

8

9}, István Kertész¹, György Trencsényi^{1

2

3}

Affiliations

¹ Division of Nuclear Medicine and Translational Imaging, Department of Medical Imaging, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary.
² Doctoral School of Clinical Medicine, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary.
³ Gyula Petrányi Doctoral School of Allergy and Clinical Immunology, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary.
⁴ Department of Pathology, Faculty of Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary.
⁵ Eötvös Loránd University, Faculty of Science, Institute of Chemistry, Budapest, Hungary.
⁶ MTA-ELTE, Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös L. University, Budapest, Hungary.
⁷ Department of Medical Chemistry, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary.
⁸ MTA-DE Lendület Laboratory of Cellular Metabolism, Debrecen, Hungary.
⁹ Research Center for Molecular Medicine, University of Debrecen, Nagyerdei St. 98, H-4032 Debrecen, Hungary.

Abstract

Introduction: The aminopeptidase N (APN/CD13) receptor plays an important role in the neoangiogenic process and metastatic tumor cell invasion. Clinical and preclinical studies reported that bestatin and actinonin are cytotoxic to APN/CD13-positive tumors and metastases due to their APN/CD13-specific inhibitor properties. Our previous studies have already shown that ⁶⁸Ga-labeled NGR peptides bind specifically to APN/CD13 expressing tumor cells. The APN/CD13 specificity of ⁶⁸Ga-NGR radiopharmaceuticals enables the following of the efficacy of antiangiogenic therapy with APN/CD13-specific inhibitors using positron emission tomography (PET). The aim of this in vivo study was to assess the antitumor effect of bestatin and actinonin treatment in subcutaneous transplanted HT1080 and B16-F10 tumor-bearing animal models using ⁶⁸Ga-NODAGA-c(NGR).

Materials and methods: Three days after the inoculation of HT1080 and B16-F10 cells, mice were treated with intraperitoneal injection of bestatin (15 mg/kg) or actinonin (5 mg/kg) for 7 days. On the 5^th and 10^th day, in vivo PET scans and ex vivo biodistribution studies were performed 90 min after intravenous injection of 5.5 ± 0.2 MBq⁶⁸Ga-NODAGA-c(NGR).

Results: Control-untreated HT1080 and B16-F10 tumors were clearly visualized by the APN/CD13-specific ⁶⁸Ga-NODAGA-c(NGR) radiopharmaceutical. The western blot analysis also confirmed the strong APN/CD13 positivity in the investigated tumors. We found significantly (p ≤ 0.05) lower radiopharmaceutical uptake after bestatin treatment and higher radiotracer accumulation in the actinonin-treated HT1080 tumors. In contrast, significantly lower (p ≤ 0.01) ⁶⁸Ga-NODAGA-c(NGR) accumulation was observed in both bestatin- and actinonin-treated B16-F10 melanoma tumors compared to the untreated-control tumors. Bestatin inhibited tumor growth and ⁶⁸Ga-NODAGA-c(NGR) uptake in both tumor models.

Conclusion: The bestatin treatment is suitable for suppressing the neoangiogenic process and APN/CD13 expression of experimental HT1080 and B16-F10 tumors; furthermore, ⁶⁸Ga-NODAGA-c(NGR) is an applicable radiotracer for the in vivo monitoring of the efficacy of the APN/CD13 inhibition-based anticancer therapies.

MeSH terms

Acetates* / pharmacokinetics
Acetates* / pharmacology
Animals
CD13 Antigens* / antagonists & inhibitors
CD13 Antigens* / metabolism
Gallium Radioisotopes* / pharmacokinetics
Gallium Radioisotopes* / pharmacology
Heterocyclic Compounds, 1-Ring* / pharmacokinetics
Heterocyclic Compounds, 1-Ring* / pharmacology
Humans
Male
Melanoma, Experimental* / diagnostic imaging
Melanoma, Experimental* / enzymology
Mice
Mice, SCID
Molecular Imaging*
Neoplasm Proteins* / antagonists & inhibitors
Neoplasm Proteins* / metabolism
Oligopeptides* / pharmacokinetics
Oligopeptides* / pharmacology
Radiopharmaceuticals* / pharmacokinetics
Radiopharmaceuticals* / pharmacology

Substances

1-(1,3-carboxypropyl)-4,7-carboxymethyl-1,4,7-triazacyclononane
Acetates
Gallium Radioisotopes
Heterocyclic Compounds, 1-Ring
NGR peptide
Neoplasm Proteins
Oligopeptides
Radiopharmaceuticals
CD13 Antigens