FIG. 8.

Effect of HIF1A 5′-UTR on luciferase expression. (A) MCF-7 cells were cotransfected with pSV-Renilla and firefly luciferase (LUC) reporter genes containing 572 bp of 5′-FS from the human HIF1A gene, followed by either 284 or 32 bp of the 5′-UTR. (B) Transfected cells were exposed to heregulin or vehicle for 24 h, and the ratio of firefly luciferase to Renilla (Relative Luciferase) activity was determined. The mean and standard deviation for each condition are shown based upon three independent transfections. (C) Expression of Renilla (Ren) and firefly luciferase (Luc) mRNA in transfected cells was determined by RT-PCR. The ratio of Renilla to firefly luciferase expression was determined by densitometry for the 20- and 24-cycle PCR but was not determined (N/D) for the 16-cycle PCR due to the low levels of product.