title: Supramolecular Probes for Assessing Glutamine Uptake Enable Semi-Quantitative Metabolic Models in Single Cells.
abstract: We describe a supramolecular surface competition assay for quantifying glutamine uptake from single cells. Cy3-labeled cyclodextrins were immobilized on a glass surface as a supramolecular host/FRET donor, and adamantane-BHQ2 conjugates were employed as the guest/quencher. An adamantane-labeled glutamine analog was selected through screening a library of compounds and validated by cell uptake experiments. When integrated onto a single cell barcode chip with a multiplex panel of 15 other metabolites, associated metabolic enzymes, and phosphoproteins, the resultant data provided input for a steady-state model that describes energy potential in single cells and correlates that potential with receptor tyrosine kinase signaling. We utilize this integrated assay to interrogate a dose-dependent response of model brain cancer cells to EGFR inhibition. We find that low-dose (1 μM erlotinib) drugging actually increases cellular energy potential even as glucose uptake and phosphoprotein signaling is repressed. We also identify new interactions between phosphoprotein signaling and cellular energy processes that may help explain the facile resistance exhibited by certain cancer patients to EGFR inhibitors.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Min
authors.initials: M
authors.lastname: Xue
authors.affiliation: Department of Molecular and Medical Pharmacology, University of California , Los Angeles, California 90095, United States.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Yapeng
authors.initials: Y
authors.lastname: Su
authors.affiliation: Department of Molecular and Medical Pharmacology, University of California , Los Angeles, California 90095, United States.
authors.forename: Dazy
authors.initials: D
authors.lastname: Johnson
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , Pasadena, California 91125, United States.|Department of Molecular and Medical Pharmacology, University of California , Los Angeles, California 90095, United States.
authors.forename: James R
authors.initials: JR
authors.lastname: Heath
mesh_terms: D001932:Brain Neoplasms / Q000188:drug therapy / Q000378:metabolism*; D002232:Carbocyanines / Q000737:chemistry; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D066246:ErbB Receptors / Q000037:antagonists & inhibitors; D000069347:Erlotinib Hydrochloride / Q000494:pharmacology; D031541:Fluorescence Resonance Energy Transfer; D005909:Glioblastoma / Q000188:drug therapy / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism*; D006801:Humans; D015335:Molecular Probes
chemical_list: D002232:Carbocyanines; D015335:Molecular Probes; C089187:cyanine dye 3; D005973:Glutamine; D000069347:Erlotinib Hydrochloride; C512478:EGFR protein, human; D066246:ErbB Receptors