Hypoxia inducing factor-1α regulates tumor necrosis factor-related apoptosis-inducing ligand sensitivity in tumor cells exposed to hypoxia

► 1. Hypoxia- and DEF-induced HIF-1α activation inhibited the TRAIL-mediated apoptosis. ► 2. HIF-1α inactivation increased the sensitivity to TRAIL in hypoxic tumor cells. ► 3. Knock-down of HIF-1α sensitized hypoxic tumor cells to TRAIL-mediated cell death.