Fig. 3: cfDNA release upon normoxic and hypoxic conditions.
From: Hypoxia differently modulates the release of mitochondrial and nuclear DNA
After seeding SW620 cells for 24 h, the culture medium was replaced with a fresh medium and cells were placed in two different incubators: one with normoxic conditions (21% O2) and the other with hypoxic conditions (0.5% O2). Different aliquots of the same supernatant were sampled during 3 days (D1–D3, days of sample collection). Total concentrations of nuclear (a) and mitochondrial (b) extracellular cfDNA were quantified by qPCR. cfDNA [0–24] corresponds to the concentration of released DNA during the first 24 h; cfDNA [24–48] corresponds to the concentration of released DNA between the 24th and 48th hour of incubation; cfDNA [48–72] corresponds to the concentration of released DNA between the 48th and 72nd hour of incubation. The proportions of nuclear or mitochondrial DNA newly released during each period, as compared to the total concentration measured each day, are shown in c, d, respectively; e shows the nuclear DII of supernatants from cells cultured in normoxia (white square, dashed line) or in hypoxia (dark triangle, solid line); f shows the MNR of supernatants from cells cultured in normoxia (white square, dashed line) or in hypoxia (dark triangle, solid line). Values are presented as mean (±) standard error of four independent wells, each performed in triplicate. cfDNA: extracellular cell-free DNA; DII: DNA integrity index; MNR: mitochondrial-to-nuclear DNA ratio; n.s.: not significant. p-Values significance: *p < 0.05, **p < 0.01, ***p ≤ 0.001 and ****p ≤ 0.0001.
