title: A (99m) Tc-tricine-HYNIC-labeled peptide targeting the neurotensin receptor for single-photon imaging in malignant tumors.
abstract: In this study, a new neurotensin (NT) analog was labeled with (99m) Tc via HYNIC chelator and tricine as coligand and investigated further. An NT (7-13) analog was prepared, and labeling with (99m) Tc was performed. The internalization rate and biodistribution of radiopeptide were studied in HT-29 cells and nude mice bearing tumor, respectively. Radiolabeling with (99m) Tc was performed at high specific activities (54 MBq/nmol) with an acceptable labeling yield (>95%). In vitro cell line studies showed a specific internalization uptake up to 13.23 ± 0.45% during 4 h which was blocked in the presence of excess cold peptide to 0.83 ± 0.15%. In biodistribution studies, uptake was observed in NT receptor-positive organs so that after 1 h the uptakes in mouse intestine and tumor were 1.23 ± 0.16% ID/g and 1.12 ± 0.11% ID/g, respectively. In animals co-injected with excess cold peptide, reduction uptake in tumor and intestines were 73% (1.10% vs. 0.29% ID/g at 4 h) and 61% (1.22% vs. 0.47% ID/g at 4 h) respectively. Predominant renal excretion pathway with a highest accumulation of activity in bladder was observed for this radiopeptide. This radiolabeled peptide could be a candidate for detection of NT positive tumors.
authors.affiliation: Radiation Application Research School, Nuclear Science and Technology Research Institute (NSTRI), Atomic Energy Organization of Iran (AEOI), PO Box: 11365-3486, end of Karegar Ave., Tehran, Iran.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Erfani
authors.forename: Nakisa
authors.initials: N
authors.lastname: Zarrabi Ahrabi
authors.forename: Mohammad
authors.initials: M
authors.lastname: Shafiei
authors.forename: Seyed Pezhman
authors.initials: SP
authors.lastname: Shirmardi
mesh_terms: D000818:Animals; D005998:Glycine / Q000031:analogs & derivatives* / Q000737:chemistry; D019073:HT29 Cells; D006801:Humans; D051379:Mice; D009525:Niacin / Q000031:analogs & derivatives* / Q000737:chemistry; D015609:Organotechnetium Compounds / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics; D010455:Peptides / Q000737:chemistry*; D017785:Photons; D018028:Receptors, Neurotensin / Q000378:metabolism*
chemical_list: C561328:6-hydrazinonicotinic acid; D015609:Organotechnetium Compounds; D010455:Peptides; D018028:Receptors, Neurotensin; D009525:Niacin; D005998:Glycine; C100184:tricine
keywords: 99mTc; HT-29 cells; HYNIC; neurotensin; tricine; tumor