Fig. 1. Activation of Nrf1/2 in HS27 cells upon LDR. (A) HS27 cells were irradiated with 0.5 Gy of X-rays, and incubated for 2 h or 24 h. (B) Cells were irradiated with X-rays (0.05, 0.5 and 5 Gy), and then incubated for 2 h and 24 h, respectively. Expression of Nrf1/2/3 in cytosolic and nuclear fraction was determined by Western blotting. Levels were normalized to α-tubulin and lamin B. One representative result is shown from independent experiments that yield similar results. Relative intensity is shown under each blot. (C) HS27 cells were transfected with 0.5 μg ARE-luciferase reporter plasmid, and irradiated with X-rays (0.05, 0.5 and 5 Gy). After 24 h incubation, cells were harvested, and the luciferase activity was measured. *P ＜ 0.05, **P ＜ 0.01 vs. non-radiated control.