Fig. 7: Elevated nonhomologous end-joining and genomic instability in BRCA2-mutated cancer cells exposed to WRNi.

a Representative immunofluorescence staining of DNA-PKcs p-S2056 foci in PEO4 and PEO1 cells following treatment with WRNi (5 µM) for 16 h. Cells were optionally treated with Mirin (25 µM). Cells were co-stained with PCNA to mark replicating cells. Bar graph represents quantification of % PCNA positive cells with ≥5 DNA-PKcs p-S2056 foci in individual experimental conditions. Data represent mean ± SD of three independent experiments; two-tailed unpaired t-test; p values are indicated. b Representative images of metaphase chromosome spread prepared from PEO1 and PEO4 cells treated or non-treated with WRNi (2 µM) for 48 h. Scatter plot showing relative chromosomal aberrations scored from the cells as described above. Data represent mean ± SEM of n ≥ 40 metaphase spreads analyzed under each condition over n = 3 independent experiments; Two-tailed Mann–Whitney test; p values (p = 0.3853, p < 0.0001, p < 0.0001) are indicated. c Analysis of chromosomal aberrations in BRCA2-mutated PEO1 cells following treatment with WRNi (5 µM) for 16 h. Cells were optionally treated with Mirin (25 µM) or DNA-PK inhibitor (DNA-PKi) NU7441 (10 µM). Quantification of chromosomal aberration analysis is shown. Data represent mean ± SEM of n ≥ 50 metaphase spreads analyzed under each condition over n = 3 independent experiments; Two-tailed Mann–Whitney test; p values (p < 0.0001, p < 0.000, p = 0.0023) are indicated. Structural aberrations including chromatid breaks/gaps, chromosome end-to-end fusions, dicentric and radial chromosomes are indicated by red arrows in b and c. Scale bars are shown in all representative images. In a, DAPI, PCNA, and DNA-PKcs p-S2056 foci are shown in blue, red, and green, respectively. Source data are provided as a Source Data file.