{"entity": "publication", "iuid": "f34c53feced64382a61689e6e503325f", "timestamp": "2026-08-22T08:31:32.911Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/f34c53feced64382a61689e6e503325f.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/f34c53feced64382a61689e6e503325f"}}, "title": "Influence of the Position and Composition of Radiometals and Radioiodine Labels on Imaging of Epcam Expression in Prostate Cancer Model Using the DARPin Ec1.", "authors": [{"family": "Deyev", "given": "Sergey M", "initials": "SM", "orcid": "0000-0002-3952-0631", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/fb88df2aaa8a46a5957370b9258e2834.json"}}, {"family": "Xu", "given": "Tianqi", "initials": "T", "orcid": "0000-0002-1826-4093", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/688f685bf3474e72bfab58e1fa2035b9.json"}}, {"family": "Liu", "given": "Yongsheng", "initials": "Y", "orcid": "0000-0001-5871-5779", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/a53363bbcb5b414681ee46ac22b65230.json"}}, {"family": "Schulga", "given": "Alexey", "initials": "A", "orcid": "0000-0003-3425-0828", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/45b1c8e5447c41bbb93e61706377a0c7.json"}}, {"family": "Konovalova", "given": "Elena", "initials": "E"}, {"family": "Garousi", "given": "Javad", "initials": "J"}, {"family": "Rinne", "given": "Sara S", "initials": "SS", "orcid": "0000-0003-2141-3982", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/3aea3edd98b441c98bb527b1e0c911f5.json"}}, {"family": "Larkina", "given": "Maria", "initials": "M", "orcid": "0000-0003-1176-2441", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/557c8a9c8b2142a7a88d6211335d24e4.json"}}, {"family": "Ding", "given": "Haozhong", "initials": "H", "orcid": "0000-0003-1093-8222", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/3ee6fb5a9b694c1d8a40cc41e9d16146.json"}}, {"family": "Gr\u00e4slund", "given": "Torbj\u00f6rn", "initials": "T", "orcid": "0000-0002-5391-600X", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/afff2431691348539334ab0e86158505.json"}}, {"family": "Orlova", "given": "Anna", "initials": "A", "orcid": "0000-0001-6120-2683", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/1c374f429702489494c05f84f298b4b7.json"}}, {"family": "Tolmachev", "given": "Vladimir", "initials": "V", "orcid": "0000-0002-6122-1734", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/896ae9fae8b74251afe11b4354c62794.json"}}, {"family": "Vorobyeva", "given": "Anzhelika", "initials": "A", "orcid": "0000-0002-4778-3909", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/99703faa11ab4c19aff2f426f61c3134.json"}}], "type": "journal article", "published": "2021-07-17", "journal": {"title": "Cancers (Basel)", "issn": "2072-6694", "volume": "13", "issue": "14", "issn-l": "2072-6694"}, "abstract": "The epithelial cell adhesion molecule (EpCAM) is intensively overexpressed in 40-60% of prostate cancer (PCa) cases and can be used as a target for the delivery of drugs and toxins. The designed ankyrin repeat protein (DARPin) Ec1 has a high affinity to EpCAM (68 pM) and a small size (18 kDa). Radiolabeled Ec1 might be used as a companion diagnostic for the selection of PCa patients for therapy. The study aimed to investigate the influence of radiolabel position (N- or C-terminal) and composition on the targeting and imaging properties of Ec1. Two variants, having an N- or C-terminal cysteine, were produced, site-specifically conjugated to a DOTA chelator and labeled with cobalt-57, gallium-68 or indium-111. Site-specific radioiodination was performed using ((4-hydroxyphenyl)-ethyl)maleimide (HPEM). Biodistribution of eight radiolabeled Ec1-probes was measured in nude mice bearing PCa DU145 xenografts. In all cases, positioning of a label at the C-terminus provided the best tumor-to-organ ratios. The non-residualizing [125I]I-HPEM label provided the highest tumor-to-muscle and tumor-to-bone ratios and is more suitable for EpCAM imaging in early-stage PCa. Among the radiometals, indium-111 provided the highest tumor-to-blood, tumor-to-lung and tumor-to-liver ratios and could be used at late-stage PCa. In conclusion, label position and composition are important for the DARPin Ec1.", "doi": "10.3390/cancers13143589", "pmid": "34298801", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC8304184"}, {"db": "pii", "key": "cancers13143589"}], "notes": [], "created": "2026-08-21T13:01:42.532Z", "modified": "2026-08-21T13:01:42.881Z"}