Fig. 1.

Overexpression of Nrf2 attenuates the CK2 downregulation-induced ROS production and senescence phenotypes in human cancer cells. MCF-7 and HCT116 cells were transfected with CK2α siRNA in the absence or presence of the Nrf2 cDNA for 48 h. (A) Cells were lysed and electrophoresed on a 10% SDS–polyacrylamide gel. Protein bands were visualized by immunoblotting (left panel). Representative data from three independent experiments are shown. Graphs show the quantification of the protein levels relative to that of β-actin (right panel). (B) Cells were stained with 5-bromo-4-chloro-3-indolyl-β-D-galactoside, and the percentage of blue-stained cells was measured. (C) The cells were then incubated with 10 μM CM-H₂DCFDA. Fluorescence intensity was determined by flow cytometry analysis (left panel). Representative data from three independent experiments are shown. The graphs show the relative fluorescence level (right panel). All data are presented as means ± SEM. *P < 0.05; **P < 0.01; ***P < 0.001.