Fig. 7

K568R mutation of Ku80 sensitizes cancer cells to DNA damage agents and inhibits cancer development. a The Ku80 K568R mutation decreases the efficiency of DNA DSB repair, as shown by the increase in the number of residual γ-H2AX foci after 8 Gy irradiation. DAPI was used to be nuclear staining. b The γ-H2AX foci in 50 cells were quantified and analyzed. A p-value less than 0.05 indicates a significant difference; two-tailed Student’s t-test. c Flow cytometric histograms of apoptosis detection. Ku80 WT and K568R mutant HeLa cells were irradiated with 8 Gy of γ-ray. Apoptosis was detected at 48 h after irradiation. d Quantification of apoptosis induction was performed. The data are the means ± SDs from three independent experiments. P < 0.001, comparison between the wild-type group and the Ku80 WT group. e Growth curves of Ku80 WT and Ku80 K568R mutant HeLa cells generated using the xCELLigence Real-Time Cell Analyzer (RTCA)-MP system. f Survival of Ku80 WT and K568R mutant HeLa cells exposed to IR. The data are the means ± SDs from three independent experiments. *p < 0.1, **p < 0.01, ***p < 0.001. g The sensitivity of Ku80 WT and Ku80 K568R mutant HeLa cells to DNA damage or replication stress-inducing agents was determined by the xCELLigence Real-Time Cell Analyzer (RTCA)-MP system. h, i, j Tumorigenicity of Ku80 WT and Ku80 K568R mutant HeLa cells in nude mice. Ku80 WT (0.1 ml; 1 × 10⁶ cells) or Ku80 K568R mutant HeLa cells were injected into each nude mouse (n = 5 in each group). In addition, we list the treatment details in the Materials and Methods in available supplementary file. Tumor growth condition was recorded in every 3 days. The weight of tumor tissues were measured after sacrificing the mice. Data are presented as means ± SDs. A p-value less than 0.05 indicates a significant difference. **p < 0.01. β-actin was assayed to ensure equivalent loading and transfer