{"entity": "publication", "iuid": "72a8c3b95b674cf186a9698113f12544", "timestamp": "2026-08-20T21:13:09.205Z", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/72a8c3b95b674cf186a9698113f12544.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/72a8c3b95b674cf186a9698113f12544"}}, "title": "Synthesis and Preclinical Evaluation of Radio-Iodinated GRPR/PSMA Bispecific Heterodimers for the Theranostics Application in Prostate Cancer.", "authors": [{"family": "Abouzayed", "given": "Ayman", "initials": "A"}, {"family": "Yim", "given": "Cheng-Bin", "initials": "CB"}, {"family": "Mitran", "given": "Bogdan", "initials": "B"}, {"family": "Rinne", "given": "Sara S", "initials": "SS"}, {"family": "Tolmachev", "given": "Vladimir", "initials": "V", "orcid": "0000-0002-6122-1734", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/896ae9fae8b74251afe11b4354c62794.json"}}, {"family": "Larhed", "given": "Mats", "initials": "M", "orcid": "0000-0001-6258-0635", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/225695195abc4233bd141e6858e72e7f.json"}}, {"family": "Rosenstr\u00f6m", "given": "Ulrika", "initials": "U"}, {"family": "Orlova", "given": "Anna", "initials": "A", "orcid": "0000-0001-6120-2683", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/1c374f429702489494c05f84f298b4b7.json"}}], "type": "journal article", "published": "2019-07-23", "journal": {"title": "Pharmaceutics", "issn": "1999-4923", "volume": "11", "issue": "7", "issn-l": null}, "abstract": "Gastrin-releasing peptide receptor (GRPR) and prostate-specific membrane antigen (PSMA) are overexpressed in most prostate cancers. GRPR expression is higher in early stages while PSMA expression increases with progression. The possibility of targeting both markers with a single theranostics radiotracer could improve patient management. Three GRPR/PSMA-targeting bispecific heterodimers (urea derivative PSMA-617 and bombesin-based antagonist RM26 linked via X-triazolyl-Tyr-PEG2, X = PEG2 (BO530), (CH2)8 (BO535), none (BO536)) were synthesized by solid-phase peptide synthesis. Peptides were radio-iodinated and evaluated in vitro for binding specificity, cellular retention, and affinity. In vivo specificity for all heterodimers was studied in PC-3 (GRPR-positive) and LNCaP (PSMA-positive) xenografts. [125I]I-BO530 was evaluated in PC-3pip (GRPR/PSMA-positive) xenografts. Micro single-photon emission computed tomography/computed tomography (microSPECT/CT) scans were acquired. The heterodimers were radiolabeled with high radiochemical yields, bound specifically to both targets, and demonstrated high degree of activity retention in PC-3pip cells. Only [125I]I-BO530 demonstrated in vivo specificity to both targets. A biodistribution study of [125I]I-BO530 in PC-3pip xenografted mice showed high tumor activity uptake (30%-35%ID/g at 3 h post injection (pi)). Activity uptake in tumors was stable and exceeded all other organs 24 h pi. Activity uptake decreased only two-fold 72 h pi. The GRPR/PSMA-targeting heterodimer [125I]I-BO530 is a promising agent for theranostics application in prostate cancer.", "doi": "10.3390/pharmaceutics11070358", "pmid": "31340483", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC6680768"}, {"db": "pii", "key": "pharmaceutics11070358"}], "notes": [], "created": "2026-08-20T13:42:56.984Z", "modified": "2026-08-20T13:42:57.066Z"}