title: Novel Tc-99m labeled ELR-containing 6-mer peptides for tumor imaging in epidermoid carcinoma xenografts model: a pilot study.
abstract: OBJECTIVE
  ELR-containing peptides targeting CXCR2 could be the excellent candidate for targeting ligand of molecular tumor imaging. In this study, we had developed two ELR-containing 6-mer peptides and evaluated the diagnostic performance of Tc-99m labeled 6-mer peptides as a molecular imaging agent in murine models bearing KB epidermoid carcinoma.
  
  
  METHODS
  Peptides were synthesized using Fmoc solid phase peptide synthesis. Radiolabeling efficiency with Tc-99m was evaluated using instant thin-layer chromatography. In KB epidermoid cancer-bearing mice, gamma images had acquired and tumor-to-muscle uptake ratio was calculated. Competition and biodistribution studies had performed.
  
  
  RESULTS
  Two 6-mer peptides, ELR-ECG and ECG-ELR were successfully synthesized. After radiolabeling procedures with Tc-99m, the complex Tc-99m ELR-ECG and Tc-99m ECG-ELR were prepared in high yield. In the gamma camera imaging of murine model, Tc-99m ELR-ECG was substantially accumulated in the subcutaneously engrafted tumor and tumor uptake had been suppressed by the free ELR co-injection. However, Tc-99m ECG-ELR was minimally accumulated in the tumor.
  
  
  CONCLUSIONS
  Two ELR-containing 6-mer peptides, ELR-ECG and ECG-ELR, were developed as a molecular imaging agent to target CXCR2 of epidermoid carcinoma. Tc-99m ELR-ECG had showed significant uptake in tumor and it was good candidate for a tumor imaging.
authors.affiliation: Department of Nuclear Medicine, Wonkwang University School of Medicine, 344-2 Shinyong-Dong, Iksan, Jeollabuk-do, 570-711, Republic of Korea.
authors.forename: Dae-Weung
authors.initials: DW
authors.lastname: Kim
authors.forename: Woo Hyoung
authors.initials: WH
authors.lastname: Kim
authors.forename: Myoung Hyoun
authors.initials: MH
authors.lastname: Kim
authors.forename: Chang Guhn
authors.initials: CG
authors.lastname: Kim
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D007553:Isotope Labeling; D007624:KB Cells; D051379:Mice; D057054:Molecular Imaging / Q000379:methods*; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D010865:Pilot Projects; D023063:Receptors, Interleukin-8B / Q000378:metabolism; D013667:Technetium
chemical_list: D009842:Oligopeptides; D023063:Receptors, Interleukin-8B; D013667:Technetium