Selection of an optimal macrocyclic chelator improves the imaging of prostate cancer using cobalt-labeled GRPR antagonist RM26.

ABSTRACT: Gastrin-releasing peptide receptors (GRPRs) are promising targets in oligometastatic prostate cancer. We have recently used ⁵⁵Co (T_1/2 =17.5 h) as a label for next day PET imaging of GRPR expression obtaining high imaging contrast. The radionuclide-chelator combination can significantly influence the biodistribution of radiopeptides. Therefore, in this study, we hypothesized that the properties of ⁵⁵Co-labeled PEG₂-RM26 can be improved by identifying the optimal macrocyclic chelator. All analogues (X-PEG₂-RM26, X = NOTA,NODAGA,DOTA,DOTAGA) were successfully labeled with radiocobalt with high yields and demonstrated high stability. The radiopeptides bound specifically and with picomolar affinity to GRPR and their cellular processing wa

SUBMITTER: Mitran B 

PROVIDER: S-EPMC6863848 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature