title: Tc-99m Glu-Cys-Gly-His-Gly-Lys (ECG-HGK), a novel Tc-99m labeled hexapeptide for molecular tumor imaging.
abstract: Domain 5 of kinin-free high molecular weight kininogen inhibits the adhesion of many tumor cell lines, and it has been reported that the histidine-glycine-lysine (HGK)-rich region might be responsible for inhibition of cell adhesion. The authors developed HGK-containing hexapeptide, glutamic acid-cysteine-glycine (ECG)-HGK, and evaluated the utility of Tc-99m ECG-HGK for tumor imaging. Hexapeptide, ECG-HGK was synthesized using Fmoc solid-phase peptide synthesis. Radiolabeling efficiency was evaluated. The uptake of Tc-99m ECG-HGK within HT-1080 cells was evaluated in vitro. In HT-1080 tumor-bearing mice, gamma imaging and biodistribution studies were performed. The complexes Tc-99m ECG-HGK was prepared in high yield. The uptake of Tc-99m ECG-HGK within the HT-1080 tumor cells had been demonstrated by in vitro studies. The gamma camera imaging in the murine model showed that Tc-99m ECG-HGK was accumulated substantially in the HT-1080 tumor (tumor-to-muscle ratio = 5.7 ± 1.4 at 4 h), and the tumoral uptake was blocked by the co-injection of excess HGK (tumor-to-muscle ratio = 2.8 ± 0.6 at 4 h). In the present study, Tc-99m ECG-HGK was developed as a new tumor imaging agents. Our in vitro and in vivo studies revealed specific function of Tc-99m ECG-HGK for tumor imaging.
authors: Department of Nuclear Medicine and Institute of Wonkwang Medical Science, Wonkwang University School of Medicine, Iksan, Jeollabuk-do, Korea.|Research Unit of Molecular Imaging Agent (RUMIA), Wonkwang University School of Medicine, Iksan, Jeollabuk-do, Korea.
authors: Dae-Weung
authors: DW
authors: Kim
authors: Department of Nuclear Medicine and Institute of Wonkwang Medical Science, Wonkwang University School of Medicine, Iksan, Jeollabuk-do, Korea.
authors: Myoung Hyoun
authors: MH
authors: Kim
authors: Department of Nuclear Medicine and Institute of Wonkwang Medical Science, Wonkwang University School of Medicine, Iksan, Jeollabuk-do, Korea.
authors: Chang Guhn
authors: CG
authors: Kim
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000000981:diagnostic imaging*; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D015609:Organotechnetium Compounds / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D013667:Technetium / Q000737:chemistry*; D014018:Tissue Distribution
chemical_list: D009842:Oligopeptides; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C000612944:technetium 99m glutamyl-cysteinyl-glycyl-histidyl-glycyl-lysine; D013667:Technetium
keywords: HGK; Tc-99m; high molecular weight kininogen; histidine-glycine-lysine; molecular imaging