Association of HIF-1α with p300 in the presence of FIH-1, PTEN in U87 cells.

<p>A: Western blot of HIF-1α from protein lysates of U87 cells incubated overnight either in hypoxic (3% oxygen) or normoxic (21% oxygen) conditions (top panel). No change of p300 protein levels was observed in the same samples (middle panel). β-actin was used as a loading control (lower panel). B: Association of HIF-1α with p300 in U87 cells: cells were transiently transfected with either FIH-1 or a PTEN expression plasmid, or both of them together for 24 hrs, and then incubated overnight under both normoxic and hypoxic conditions. Nuclear extracts were collected and subjected to immunoprecipitation with anti-p300 antibody followed by Western blot analysis with anti-HIF-1α (top panel) and IgG (middle panel). Nuclear extracts were also subjected to western blot analysis with anti- HIF-1α antibody (bottom panel).