ROS detection assay

ROS production was detected as described previously [44]. Cells were seeded at a density of 1.5 × 10⁵ and subjected to various conditions. NCI-H460 cells or NCI-H1299 cells were pre-treated with 30 μM AMRI-59 for 6 h and then irradiated 3 or 5 Gy IR, respectively. After 48 h incubation, treated cells were incubated with 20 μM DCF-DA for 20 min and trypsinized with 1 × trypsin-EDTA at 37°C for 5 min. The cells were followed by centrifugation at 500 × g at 4°C for 5 min, and cell pellets were resuspended with ice-cold phosphate-buffered saline. ROS were detected and analyzed using a FACSort flow cytometer (Becton Dickinson, NJ, USA).