title: Near-infrared fluorescence imaging of HER-2 protein over-expression in tumour cells.
abstract: The aim of this study was to evaluate in vitro and in vivo imaging of HER-2-over-expressing tumours using near-infrared optical imaging. A fluorochrome probe was designed by coupling Cy5.5 to anti-HER-2 antibodies. Cells over-expressing (SK-BR-3 cells) or normally expressing (PE/CA-PJ34 cells) the HER-2 protein were incubated with the probe. After removing unbound probe molecules, fluorescence intensities were determined (a.u.: arbitrary units). Cells were additionally investigated using FACS and laser scanning microscopy. The probe was also injected intravenously into tumours bearing SK-BR-3 ( n=3) or PE/CA-PJ34 ( n=3). Whole-body fluorescence images were generated and analysed. The incubation of SK-BR-3 cells with the probe led to higher fluorescence intensities [2,133 (+/-143) a.u.] compared to controls [975 (+/-95) a.u.]. The results from FACS and immunocytochemical analysis were in agreement with these findings. A distinct dependency between the fluorescence intensity and the cell number used in the incubations was detected. In vivo, the relative fluorescence intensities in SK-BR-3 tumours were higher than in PE/CA-PJ34 tumours at 16-24 h after probe application. HER-2-over-expressing tumours were depictable in their original size. Labelling of HER-2 with Cy5.5 is suitable for in vitro and in vivo detection of HER-2-over-expressing tumour cells.
authors.affiliation: Institute for Diagnostic and Interventional Radiology, Friedrich Schiller University Hospital Jena, Bachstrasse 18, 07743 Jena, Germany. ingrid.hilger@med.uni-jena.de
authors.forename: Ingrid
authors.initials: I
authors.lastname: Hilger
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Leistner
authors.forename: Alexander
authors.initials: A
authors.lastname: Berndt
authors.forename: Christine
authors.initials: C
authors.lastname: Fritsche
authors.forename: Karl Michael
authors.initials: KM
authors.lastname: Haas
authors.forename: Hartwig
authors.initials: H
authors.lastname: Kosmehl
authors.forename: Werner A
authors.initials: WA
authors.lastname: Kaiser
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000737:chemistry; D005456:Fluorescent Dyes; D006801:Humans; D007150:Immunohistochemistry; D051379:Mice; D016513:Mice, SCID; D018613:Microscopy, Confocal; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D019265:Spectroscopy, Near-Infrared; D014407:Tumor Cells, Cultured
chemical_list: D005456:Fluorescent Dyes; D018719:Erb-b2 Receptor Tyrosine Kinases