Figure 3.

Relative enhancement of expression of the downstream reporter enzyme by the HIF-1α 5′UTR in various cell types. NIH3T3, HEK293, and HeLa cells were transiently transfected with pRF or pRhifF (Figure 1) as indicated. Renilla and firefly luciferase activities were determined 24 h posttransfection, and IRES activities represented as ratios of firefly to Renilla luciferase. The ratios for each cell line are graphed relative to pRF, which was given a value of 1. Data presented are the mean (±SEM) of triplicate samples from three independent experiments.