Figure 5

TUNEL assay showing that the combination of DCQ and IR induces apoptosis in DLD-1 cells under oxic and hypoxic conditions. Cells were treated with 5 μM DCQ or DMSO (0.1%) and exposed to hypoxia or incubated in oxia for 1 hour, then irradiated (2 Gy). Immediately after radiation or drug treatment, cells were replenished with fresh media containing no drugs and left in the incubator for 24 hours. The extent of DNA fragmentation was determined by TUNEL assay and measured by flow cytometry. The percentage of apoptotic cells was determined using CellQuest. Results are representative of at least two independent experiments.