Fig. 6

Chronic hypoxia reduces ATM activation after etoposide treatment. D283-MED cells were pre-incubated in 21% O₂, 1% O₂ or 0.1% O₂ prior to treatment with 20 μM etoposide for 4 h, or cells were left untreated as a control. Levels of ATM and ATM serine 1981 phosphorylation were determined using 3 independent western blots. The plots represent the densitometry of a representative western blot (a) measured using Image J