Figure 1.
Heterogeneity of Glucose and Glutamine Utilization by Proliferating Cancer Cells
(A) Cancer cell lines were labeled with a cocktail consisting of 2H-glucose, 15N-glutamine, and bromodeoxyuridine (BrdU) for 12 h. Two representative cell lines are shown: MALME3M (melanoma) and C4-2B (prostate). 12C14N and 31P mass images reveal cellular borders and details such as nuclei. BrdU incorporation by cells that divided during the labeling period is indicated by direct measurement of 81Br into nuclei that are also evident in the 12C14N and 31P mass images (example: large arrow heads). An adjacent BrdU− cell is indicated by a small arrow head. Hue saturation intensity (HSI) images display the isotope ratio measurements and therefore a map of the incorporation of 2H-glucose and 15N-glutamine. Arrows indicate metabolic labeling hotspots with features consistent with nucleoli in the 12C14N and 31P mass images. The lower bound of the scale (blue) is set to the background ratio (0%) and the upper bound (magenta) is set to reveal differences in labeling (150% and 300% above background, respectively). Scale bar, 10 μm.
(B) Dot plot of individual cancer cells, color coded according to cell line (legend). 15N-glutamine and 2H-glucose labeling expressed as percentage above natural background.
(C) 15N-glutamine labeling of cancer cell lines as a function of BrdU labeling (divided cells are BrdU+).
(D) 2H-glucose labeling of cancer cell lines as a function of BrdU labeling. For (C) and (D): red line = mean; ∗p < 0.05, ∗∗p < 0.001, ∗∗∗p < 0.0001, two-tailed t test.