Cal33 cells demonstrate greater metabolic flexibility in response to hypoxia than OSC19 cells.

<p>After 16 or 48 hours in 2% (hypoxia) or 21% oxygen (normoxia), 4×10⁴ Cal33 or OSC19 cells were plated in a Seahorse XF24 Extracellular Flux Analyzer plate. The Seahorse Analyzer records rates of OXPHOS & glycolysis via the oxygen consumption rate (OCR) and the extracellular acidification rate (ECAR) of each sample culture. A, basal OCR recorded at the assay start after 16 hour incubation. B, ATP-linked OCR is the difference between the basal OCR and the OCR after the addition of oligomycin to sample cultures (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0102452#pone.0102452.s001" target="_blank">Figure S1</a>). C, Basal ECAR recorded at the assay start. Three experiments were performed at each time point, with five samples per condition. Boxes represent the interquartile range, horizontal lines indicate the median, the T-bars indicate the range, and individual points are outliers. P values were determined by two-way ANOVA. N = normoxia (21% oxygen), H = hypoxia (2% oxygen). D, Basal OCR recorded at assay start after 48 hour incubation. E, ATP-linked OCR recorded for 48 hour cultures. F, Basal ECAR recorded after 48 hour incubation.