title: Imaging of protein synthesis: in vitro and in vivo evaluation of (44)Sc-DOTA-puromycin.
abstract: OBJECTIVE
  The purpose of this study was to investigate whether (44)Sc-labeled puromycin can be utilized for imaging of protein synthesis in vivo.
  
  
  METHODS
  For micro-positron emission tomographic (μPET) studies, 20-25 MBq of [(44)Sc]-DOTA-puromycin was administered to tumor-bearing rats, and animals were scanned for 1 h dynamically. Results were further validated by dissecting organs and tissues of the animals after the measurement and in vitro blocking experiments using puromycin or cycloheximide to block protein synthesis.
  
  
  RESULTS
  μPET images of tumor-bearing rats showed significant tumor uptake of [(44)Sc]-DOTA-puromycin and a clear-cut tumor visualization. In both blocking experiments, cellular uptake of [(44)Sc]-DOTA-puromycin ([(44)Sc]-DOTA-Pur) could be suppressed by blocking protein synthesis.
  
  
  CONCLUSIONS
  We report for the first time successful μPET imaging with (44)Sc obtained from a (44)Ti/(44)Sc generator, as well as noninvasive μPET imaging of ribosomal activity, respectively protein synthesis, with a puromycin-based radiopharmaceutical and the direct correlation between cellular uptake of [(44)Sc]-DOTA-Pur and protein synthesis.
authors.affiliation: Nuclear Physics Institute, Department of Radiopharmaceuticals, Academy of Science of the Czech Republic, Husinec-Rez 289, 25068 Husinec-Rez, Czech Republic. eigner@ujf.cas.cz
authors.forename: Sebastian
authors.initials: S
authors.lastname: Eigner
authors.forename: Denis R Beckford
authors.initials: DR
authors.lastname: Vera
authors.forename: Marco
authors.initials: M
authors.lastname: Fellner
authors.forename: Natalia S
authors.initials: NS
authors.lastname: Loktionova
authors.forename: Markus
authors.initials: M
authors.lastname: Piel
authors.forename: Ondrej
authors.initials: O
authors.lastname: Lebeda
authors.forename: Frank
authors.initials: F
authors.lastname: Rösch
authors.forename: Tobias L
authors.initials: TL
authors.lastname: Roß
authors.forename: Katerina Eigner
authors.initials: KE
authors.lastname: Henke
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006573:Heterocyclic Compounds, 1-Ring / Q000737:chemistry / Q000493:pharmacokinetics* / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008297:Male; D057054:Molecular Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D011691:Puromycin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology; D051381:Rats; D012538:Scandium / Q000737:chemistry / Q000493:pharmacokinetics*; D014018:Tissue Distribution
chemical_list: D006573:Heterocyclic Compounds, 1-Ring; D011506:Proteins; C071349:1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid; D011691:Puromycin; D012538:Scandium