HIF-1 activation is sufficient to upregulate DEC2 in osteosarcomas under normoxic condition. A. Bioinformatics analysis of DEC2 promoter reveals that a region with highly acetylated histone H3 at K27 contains potential binding sites for multiple transcription regulators including HIF-1, c-Fos/Jun, c-Myc/Max and E2F. B. HIF-1 activation is sufficient to upregulate DEC2 levels under normoxic condition. 143B cells were cultured in hypoxia workstation or treated with 100 μM of DFX for 6 h prior to harvest to stabilize HIF-1α. Western blots show HIF-1α stabilization up-regulates DEC2.