{"entity": "researcher", "timestamp": "2026-08-22T08:31:17.535Z", "family": "Dam", "given": "Johan Hygum", "initials": "JH", "orcid": "0000-0001-6577-7011", "affiliations": ["PET & Cyclotron Unit, Department of Nuclear Medicine, Odense University Hospital, Odense, Denmark.", "Department of Clinical Research, University of Southern Denmark, Odense, Denmark."], "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/researcher/8495e80a9bd54345a3d18eaf987f9dd5.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/researcher/8495e80a9bd54345a3d18eaf987f9dd5"}}, "publications": [{"entity": "publication", "iuid": "7c4c340c7b2248789c648fbbb1c2ef0e", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/7c4c340c7b2248789c648fbbb1c2ef0e.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/7c4c340c7b2248789c648fbbb1c2ef0e"}}, "title": "Preclinical Evaluation of the Copper-64 Labeled GRPR-Antagonist RM26 in Comparison with the Cobalt-55 Labeled Counterpart for PET-Imaging of Prostate Cancer.", "authors": [{"family": "Baun", "given": "Christina", "initials": "C", "orcid": "0000-0002-5199-9200", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/484f3234a1a143c38b832f22c73d1d59.json"}}, {"family": "Mitran", "given": "Bogdan", "initials": "B"}, {"family": "Rinne", "given": "Sara S", "initials": "SS", "orcid": "0000-0003-2141-3982", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/3aea3edd98b441c98bb527b1e0c911f5.json"}}, {"family": "Dam", "given": "Johan H", "initials": "JH", "orcid": "0000-0001-6577-7011", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/8495e80a9bd54345a3d18eaf987f9dd5.json"}}, {"family": "Olsen", "given": "Birgitte B", "initials": "BB", "orcid": "0000-0002-6130-0387", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/883bae2a831c459ea60c589df0eb2d4d.json"}}, {"family": "Tolmachev", "given": "Vladimir", "initials": "V", "orcid": "0000-0002-6122-1734", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/896ae9fae8b74251afe11b4354c62794.json"}}, {"family": "Orlova", "given": "Anna", "initials": "A", "orcid": "0000-0001-6120-2683", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/1c374f429702489494c05f84f298b4b7.json"}}, {"family": "Thisgaard", "given": "Helge", "initials": "H", "orcid": "0000-0001-9492-448X", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/43de528e1e1d415bbd9fc1dc5a4285e6.json"}}], "type": "comparative study", "published": "2020-12-18", "journal": {"title": "Molecules", "issn": "1420-3049", "volume": "25", "issue": "24", "issn-l": "1420-3049"}, "abstract": "Gastrin-releasing peptide receptor (GRPR) is overexpressed in the majority of prostate cancers. This study aimed to investigate the potential of 64Cu (radionuclide for late time-point PET-imaging) for imaging of GRPR expression using NOTA-PEG2-RM26 and NODAGA-PEG2-RM26. Methods: NOTA/NODAGA-PEG2-RM26 were labeled with 64Cu and evaluated in GRPR-expressing PC-3 cells. Biodistribution of [64Cu]Cu-NOTA/NODAGA-PEG2-RM26 was studied in PC-3 xenografted mice and compared to the biodistribution of [57Co]Co-NOTA/NODAGA-PEG2-RM26 at 3 and 24 h p.i. Preclinical PET/CT imaging was performed in tumor-bearing mice. NOTA/NODAGA-PEG2-RM26 were stably labeled with 64Cu with quantitative yields. In vitro, binding of [64Cu]Cu-NOTA/NODAGA-PEG2-RM26 was rapid and GRPR-specific with slow internalization. In vivo, [64Cu]Cu-NOTA/NODAGA-PEG2-RM26 bound specifically to GRPR-expressing tumors with fast clearance from blood and normal organs and displayed generally comparable biodistribution profiles to [57Co]Co-NOTA/NODAGA-PEG2-RM26; tumor uptake exceeded normal tissue uptake 3 h p.i.. Tumor-to-organ ratios did not increase significantly with time. [64Cu]Cu-NOTA-PEG2-RM26 had a significantly higher liver and pancreas uptake compared to other agents. 57Co-labeled radioconjugates showed overall higher tumor-to-non-tumor ratios, compared to the 64Cu-labeled counterparts. [64Cu]Cu-NOTA/NODAGA-PEG2-RM26 was able to visualize GRPR-expression in a murine PC model using PET. However, [55/57Co]Co-NOTA/NODAGA-PEG2-RM26 provided better in vivo stability and overall higher tumor-to-non-tumor ratios compared with the 64Cu-labeled conjugates.", "doi": "10.3390/molecules25245993", "pmid": "33352838", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC7766840"}, {"db": "pii", "key": "molecules25245993"}], "notes": [], "created": "2026-08-21T13:04:26.638Z", "modified": "2026-08-21T13:04:26.801Z"}, {"entity": "publication", "iuid": "e549f93f8adc40b7956e4761c8324bf4", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/e549f93f8adc40b7956e4761c8324bf4.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/e549f93f8adc40b7956e4761c8324bf4"}}, "title": "Selection of an optimal macrocyclic chelator improves the imaging of prostate cancer using cobalt-labeled GRPR antagonist RM26.", "authors": [{"family": "Mitran", "given": "Bogdan", "initials": "B"}, {"family": "Thisgaard", "given": "Helge", "initials": "H"}, {"family": "Rinne", "given": "Sara", "initials": "S"}, {"family": "Dam", "given": "Johan Hygum", "initials": "JH", "orcid": "0000-0001-6577-7011", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/8495e80a9bd54345a3d18eaf987f9dd5.json"}}, {"family": "Azami", "given": "Frishta", "initials": "F"}, {"family": "Tolmachev", "given": "Vladimir", "initials": "V", "orcid": "0000-0002-6122-1734", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/896ae9fae8b74251afe11b4354c62794.json"}}, {"family": "Orlova", "given": "Anna", "initials": "A", "orcid": "0000-0001-6120-2683", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/1c374f429702489494c05f84f298b4b7.json"}}, {"family": "Rosenstr\u00f6m", "given": "Ulrika", "initials": "U"}], "type": "journal article", "published": "2019-11-19", "journal": {"title": "Sci Rep", "issn": "2045-2322", "volume": "9", "issue": "1", "pages": "17086", "issn-l": "2045-2322"}, "abstract": "Gastrin-releasing peptide receptors (GRPRs) are promising targets in oligometastatic prostate cancer. We have recently used 55Co (T1/2 = 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 was characterized by low internalization. The best binding capacity was found for DOTA-PEG2-RM26. Ex vivo biodistribution in PC-3 xenografted mice was characterized by rapid blood clearance via renal excretion. Tumor uptake was similar for all conjugates at 3 h pi, exceeding the uptake in all other organs. Higher kidney uptake and longer retention were associated with N-terminal negative charge (DOTAGA-containing conjugate). Tumor-to-organ ratios increased over time for all constructs, although significant chelator-dependent differences were observed. Concordant with affinity measurements, DOTA-analog had the best retention of activity in tumors, resulting in the highest tumor-to-blood ratio 24 h pi, which translated into high contrast PET/CT imaging (using 55Co).", "doi": "10.1038/s41598-019-52914-y", "pmid": "31745219", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC6863848"}, {"db": "pii", "key": "10.1038/s41598-019-52914-y"}], "notes": [], "created": "2026-08-21T11:52:53.330Z", "modified": "2026-08-21T11:52:53.425Z"}]}