1 research outputs found
Supramolecular Probes for Assessing Glutamine Uptake Enable Semi-Quantitative Metabolic Models in Single Cells
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