Development and Preclinical Evaluation of 99mTc- and 186Re-Labeled NOTA and NODAGA Bioconjugates Demonstrating Matched Pair Targeting of GRPR-Expressing Tumors

PURPOSE: The goal of this work was to develop hydrophilic gastrin-releasing peptide receptor (GRPR)-targeting complexes of the general formula fac-[M(CO)3(L)]+ [M = natRe, 99mTc, 186Re; L: NOTA for 1, NODAGA for 2] conjugated to a powerful GRPR peptide antagonist (DPhe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2) via a 6-aminohexanoic acid linker.

PROCEDURES: Metallated-peptides were prepared employing the [M(OH2)3(CO)3]+ [M = Re, 99mTc, 186Re] precursors. Re-1/2 complexes were characterized with HR-MS. IC50 studies were performed for peptides 1/2 and their respective Re-1/2 complexes in a binding assay utilizing GRPR-expressing human PC-3 prostate cancer cells and [125I]I-Tyr4-BBN as the competing ligand. The 99mTc/186Re-complexes were identified by HPLC co-injection with their Re-analogues. All tracers were challenged in vitro at 37 °C against cysteine/histidine (phosphate-buffered saline 10 mM, pH 7.4) and rat serum. Biodistribution and micro-SPECT/CT imaging of [99mTc]Tc-1/2 and [186Re]Re-2 were performed in PC-3 tumor-bearing ICR SCID mice.

RESULTS: High in vitro receptor affinity (IC50 2-3 nM) was demonstrated for all compounds. The 99mTc/186Re-tracers were found to be hydrophilic (log D7.4 ≤ - 1.35) and highly stable. Biodistribution in PC-3 xenografted mice revealed good tumor uptake (%ID/g at 1 h: 4.3 ± 0.7 for [99mTc]Tc-1, 8.3 ± 0.9 for [99mTc]Tc-2 and 4.2 ± 0.8 for [186Re]Re-2) with moderate retention over 24 h. Rapid renal clearance was observed for [99mTc]Tc-2 and [186Re]Re-2 (> 84 % at 4 h), indicating favorable pharmacokinetics. Micro-SPECT/CT images for the 99mTc-tracers clearly visualized PC-3 tumors in agreement with the biodistribution data and with superior imaging properties found for [99mTc]Tc-2.

CONCLUSIONS: [99mTc]Tc-2 shows promise for further development as a GRPR-imaging agent. [186Re]Re-2 demonstrated very similar in vivo behavior to [99mTc]Tc-2, and further studies are therefore justified to explore the theranostic potential of our approach for targeting of GRPR-positive cancers.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:23

Enthalten in:

Molecular imaging and biology - 23(2021), 1 vom: 18. Feb., Seite 52-61

Sprache:

Englisch

Beteiligte Personen:

Makris, George [VerfasserIn]
Bandari, Rajendra P [VerfasserIn]
Kuchuk, Marina [VerfasserIn]
Jurisson, Silvia S [VerfasserIn]
Smith, Charles J [VerfasserIn]
Hennkens, Heather M [VerfasserIn]

Links:

Volltext

Themen:

1,4,7-triazacyclononane-N,N',N''-triacetic acid
1-(1,3-carboxypropyl)-4,7-carboxymethyl-1,4,7-triazacyclononane
56491-86-2
7440-15-5
7440-26-8
Acetates
Gastrin-releasing peptide receptor
Heterocyclic Compounds, 1-Ring
Journal Article
Ligands
Micro-SPECT/CT imaging
Organometallic complexes
Peptides
Prostate cancer
Radioisotopes
Receptors, Bombesin
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Rhenium
Rhenium-186
Technetium
Technetium-99m
Theranostics
Tricarbonyl complexes

Anmerkungen:

Date Completed 25.08.2021

Date Revised 26.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s11307-020-01537-1

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM314591303