Regulation of HIF-1 expression in osteosarcoma cells.

<p>A, Western blots showing the time course of HIF-1α and HIF-2α stabilisation and protein levels of the HIF-1 transcriptional target carbonic anhydrase IX (CA IX) in 791T, HOS and U2OS cells after exposure to hypoxia. GAPDH is a loading control. Data are representative of 3 independent experiments. B, Graphs show 2^(−ΔΔCT) where CT is the cross-threshold and represents the change in Glut-1 mRNA expression with time in 791T, HOS and U2OS cells in hypoxia relative to normoxia, where 1 would be equivalent expression in normoxia and hypoxia and greater than 1 represents an increase in hypoxia relative to normoxia. Data are the mean ± SEM of 2 independent experiments. C, VEGF-A levels in the supernatant of HOS and U2OS cells detected by enzyme-linked immunosorbent assay after 24 hours in normoxia or hypoxia, normalised to cell number. Data are the mean ± SEM of 3 independent experiments. * indicates p<0.05 as determined by the 2-tailed student t-test.