Figure 7.

Analysis of the effect of hypoxia on chimeric mRNAs containing pairwise combinations of the VEGF 5′UTR, coding region, and 3′UTR. Time courses of degradation of the f5′V-GH-3′V, f5′V-164–3′GH, or f164–3′V mRNAs from cells incubated under normoxia (open symbols) or hypoxia (closed symbols) for 24 h. The graphs show data as mean ± SEM for two independent experiments, either normalized for GAPDH (left panels) or without normalization (right panels). The levels of serum induction observed for the f5′V-GH-3′V reporter gene were 6.4- and 5.5-fold under normoxia and 4.9- and 6.0-fold under hypoxia. For the f5′V-164–3′GH reporter gene the serum induction was 5.7- and 6.3-fold under normoxia and 8.4- and 8.0-fold under hypoxia. For the f164–3′V reporter gene the serum induction was 5.2- and 9.3-fold under normoxia and 6.6- and 8.3-fold under hypoxia. The maximal levels of induction (expressed as a ratio to the GAPDH level) for the f5′V-GH-3′V reporter gene were 0.22 and 0.27 under normoxia and 0.24 and 0.21 under hypoxia. The maximal levels of induction for the f5′V-164–3′GH reporter gene were 0.18 and 0.22 under normoxia and 0.18 and 0.30 under hypoxia. The maximal levels of induction for the f164–3′V reporter gene were 0.22 and 0.36 under normoxia and 0.19 and 0.21 under hypoxia.