Involvement of p53 in MIF-induced HIF-1 activation.

<p>(A and B) MDA-MB-231 cells and Saos-2 cells were exposed to 20% or 1% O₂ conditions with or without rhMIF treatment for 4 h and then harvested for immunoblot assay for p53 (A) and HIF-1α and HIF-1β protein (B). (C and D) MCF-7 cells and Saos-2 cells were transfected with p2.1 reporter and pRL-SV40 (C). MCF-7 cells transfected with pSUPER (EV) or pSUPER-p53(p53) were transfected with p2.1 reporter and pRL-SV40 (D). Cells were exposed to 20% and 1% O₂ conditions with or without rhMIF treatment and then harvested for luciferase assay. Fold induction of relative luciferase activity was calculated. A normalized mean value±S.D. of three independent transfections is shown as fold induction. *; <i>p</i><0.05 compared to respective control (ANOVA). (E) MCF-7 and MDA-MB-231 cells transfected with pFLAG-MIF-wt plasmid were exposed to 1% O₂ and then cells were harvested. 500 µg of lysates were incubated with anti-FLAG affinity agarose beads and captured protein was eluted and analyzed by Western blot with anti-p53 antibody. 50 µg of lysate were analyzed by Western blot with anti-p53 antibody.