Figure 5

Knockdown of Ku80 enhances cisplatin-induced growth inhibition and apoptosis in A549/DDP cells. (A) RT-PCR analysis of Ku80 mRNA level in A549/DDP cells transfected with Ku80 siRNA (siKu80) or non-target sequence siRNA (Scramble). (B) Western blot analysis of Ku80 protein level in A549/DDP cells transfected with siKu80 or Scramble. (C) A549/DDP cells were transfected with siKu80 or Scramble and then treated with different concentrations of cisplatin for 24 h. Cell viability was determined by MTT assay. Data represented mean ± SD for three replicate experiments. (D) A549/DDP cells were transfected with siKu80 or Scramble and then treated with 6 μg/ml cisplatin for 24 h. The cells were collected and stained with Annexin-V-FITC and PI. Shown were representative images of three independent experiments. (E) A549/DDP cells were transfected with siKu80 or Scramble and then treated with 6 μg/ml cisplatin for 24 h. The cells were collected and subjected to western blot analysis for the detection of Ku80, cleaved caspase-3 and cleaved PARP levels. Shown were representative blots of three independent experiments. (F) Quantification of Ku80, cleaved caspase-3 and cleaved PARP levels as shown in (E). Data were presented as mean ± SD, n = 3. *P < 0.05.