Figure 2

Oxidative stress is involved in A549 cells sensitization to TRAIL-mediated apoptosis induced by CSE. A549 cells were pretreated with 5 mM NAC and exposed to 5% cigarette smoke extract (CSE) or 500 mM H₂O₂ and/or 100 ng/ml of recombinant human TRAIL (T100) for 6 h in serum free media. Caspase-3 activity was then measured from the whole lysate. Experiments were repeated three separate times. Results are expressed as means ± SEM. Bars with different superscripts are significantly different (p < 0.05).