Fig. 3. Effect of CK2 inhibitors on HIF-1 transcriptional activity in HepG2 cells. Cells were incubated for 16 hours under normoxia or hypoxia in the presence of different concentrations (µM) of DRB or apigenin (API). (A,B) Cells were cotransfected with pGL3-6HRE and pRL plasmids. HIF-1 activity is expressed as the ratio of native firefly luciferase to synthetic Renilla luciferase activity (means ± 1 s.d.; n=3). (C) Real-time PCR analysis of the aldolase mRNA level. Relative aldolase mRNA levels were calculated as the ratio of aldolase expression in hypoxia-incubated cells to these in control normoxic cells, both normalised to -tubulin levels. ^*P<0.05, ^**P<0.01, ^***P<0.001, NS, not significant vs. normoxia; (^*)P<0.05, (^**)P<0.01, (^***)P<0.001, (NS), not significant vs. hypoxia.