title: Receptor-targeted quantum dots: fluorescent probes for brain tumor diagnosis.
abstract: The intraoperative diagnosis of brain tumors and the timely evaluation of biomarkers that can guide therapy are hindered by the paucity of rapid adjunctive studies. This study evaluates the feasibility and specificity of using quantum dot-labeled antibodies for rapid visualization of epidermal growth factor receptor (EGFR) expression in human brain tumor cells and in surgical frozen section slides of glioma tissue. Streptavidin-coated quantum dots (QDs) were conjugated to anti-EGFR antibodies and incubated with target cultured tumor cells and tissues. The experiments were conducted first in human glioma tumor cell lines with elevated levels of EGFR expression (SKMG-3, U87) and then in frozen tissue sections of glioblastoma multiforme and of oligodendroglioma. The bioconjugated QDs used in the study were found to bind selectively to brain tumor cells expressing EGFR. QD complexed quickly to the cell membrane (less than 15 min), and binding was highly specific and depended on the expression level of EGFR on the cell membrane. Tissue experiments showed that only tumor specimens expressing EGFR were labeled in less than 30 min by QD complexes. These findings demonstrate that QD-labeled antibodies can provide a quick and accurate method for characterizing the presence or absence of a specific predictive biomarker.
authors.affiliation: University of Southern California, Department of Biomedical Engineering, Los Angeles, California 90089, USA.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Wang
authors.forename: William H
authors.initials: WH
authors.lastname: Yong
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Sun
authors.forename: P Thomas
authors.initials: PT
authors.lastname: Vernier
authors.forename: H Phillip
authors.initials: HP
authors.lastname: Koeffler
authors.forename: Martin A
authors.initials: MA
authors.lastname: Gundersen
authors.forename: Laura
authors.initials: L
authors.lastname: Marcu
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D016503:Drug Delivery Systems / Q000379:methods*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D005456:Fluorescent Dyes; D006801:Humans; D008856:Microscopy, Fluorescence / Q000379:methods*; D045663:Quantum Dots
chemical_list: D014408:Biomarkers, Tumor; D005456:Fluorescent Dyes; D004815:Epidermal Growth Factor