Fig. 2.

CK2 downregulation reduces the transcriptional activity and expression of Nrf2 in human cancer cells. (A) MCF-7 and HCT116 cells were co-transfected with the ARE luciferase construct and CK2α siRNA or pcDNA-HA-CK2α. The firefly luciferase activity was measured 24 h after transfection and normalized to Renilla luciferase activity. (B, C) Cells were transfected with CK2α siRNA or pcDNA-HA-CK2α for 48 h. (B) Total RNA was extracted from the cells, and RT-PCR was performed using specific primers. PCR products were resolved on a 1.5% agarose gel (upper panel). Graphs show the quantification of the mRNA levels of each gene relative to that of β-actin (bottom panels). (C) Cells were lysed and electrophoresed on a 10% SDS–polyacrylamide gel. Protein bands were visualized by immunoblotting (upper panel). Graphs show the quantification of the protein levels relative to β-actin levels (bottom panels). All data are shown as means ± SEM. *P <0.05; **P < 0.01; ***P < 0.001.