title: Molecular imaging of the translocator protein (TSPO) in a pre-clinical model of breast cancer.
abstract: OBJECTIVE
  To quantitatively evaluate the utility of a translocator protein (TSPO)-targeted near-infrared (NIR) probe (NIR-conPK11195) for in vivo molecular imaging of TSPO in breast cancer.
  
  
  METHODS
  NIR-conPK11195 uptake and TSPO-specificity were validated in TSPO-expressing human breast adenocarcinoma cells (MDA-MB-231). In vivo NIR-conPK11195 biodistribution and accumulation were quantitatively evaluated in athymic nude mice bearing MDA-MB-231 xenografts.
  
  
  RESULTS
  Fluorescence micrographs illustrated intracellular labeling of MDA-MB-231 cells by NIR-conPK11195. Quantitative uptake and competition assays demonstrated dose-dependent (p < 0.001) and TSPO-specific (p < 0.001) NIR-conPK11195 uptake. In vivo, NIR-conPK11195 preferentially labeled MDA-MB-231 tumors with an 11-fold (p < 0.001) and 7-fold (p < 0.001) contrast enhancement over normal tissue and unconjugated NIR dye, respectively.
  
  
  CONCLUSIONS
  NIR-conPK11195 appears to be a promising TSPO-targeted molecular imaging agent for visualization and quantification of breast cancer cells in vivo. This research represents the first study to demonstrate the feasibility of TSPO imaging as an alternative breast cancer imaging approach.
authors: Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA.
authors: Shelby K
authors: SK
authors: Wyatt
authors: H Charles
authors: HC
authors: Manning
authors: Mingfeng
authors: M
authors: Bai
authors: Stephanie N
authors: SN
authors: Bailey
authors: Pascal
authors: P
authors: Gallant
authors: Guobin
authors: G
authors: Ma
authors: Laura
authors: L
authors: McIntosh
authors: Darryl J
authors: DJ
authors: Bornhop
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000473:pathology; D045744:Cell Line, Tumor; D002470:Cell Survival; D005260:Female; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D057054:Molecular Imaging / Q000379:methods*; D015335:Molecular Probes / Q000737:chemistry / Q000493:pharmacokinetics; D018079:Receptors, GABA / Q000378:metabolism*; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors; D014018:Tissue Distribution; D051598:Whole Body Imaging
chemical_list: D015335:Molecular Probes; D018079:Receptors, GABA; C499229:TSPO protein, human