Figure 1.

Impact of checkpoint kinase 2-small interfering RNA (CHK2-siRNA) on CHK2 in A549 cells treated with CpG oligodeoxynucleotide (ODN) plus X-rays.

Notes: A, control group; B, CpG group; C, X-ray group; D, CpG + X-ray group; E, CHK2-siRNA + CpG + X-ray group. Total extract from A549 cells was immunoblotted against CHK2, phospho-CHK2 (Thr68), and β-actin at the indicated time points following irradiation. CHK2 and phospho-CHK2 status were assessed by Western blot using CHK2 and phospho-CHK2 antibody, respectively, and equal gel loading was verified using an anti-actin antibody. Quantitative analysis showed that the phospho-CHK2 difference between the X-ray group and CpG + X-ray group was significant at the 0.05 level (t = 12.35, P < 0.01).