Fig. 6: WRNi triggers MUS81-dependent double-strand break formation in BRCA2-mutated cancer cells.

a Immunofluorescence staining of γH2AX following treatment of PEO4 and PEO1 cells with WRNi (5 µM) for 6 h. Cells were co-stained with PCNA to identify replicating cells. Nuclei were stained with DAPI. DAPI, PCNA, and γH2AX are shown in blue, red, and green, respectively. Scale bars are shown. Bar graph represents quantification of % PCNA-positive cells with ≥10 γH2AX foci under untreated (UT) and WRNi-treated conditions. Data represent mean ± SD of three independent experiments; two-tailed unpaired t-test; p values are indicated. b Analysis of DSB formation using neutral Comet assay. Control or MUS81-depleted PEO4 and PEO1 cells were subjected to neutral comet assay following treatment with WRNi (5 µM) for 6 h. Representative images of comets obtained from individual experimental conditions are shown. Scale bars are shown. Scatter dot plot showing tail moment in individual samples. Data represent mean ± SD of n ≥ 120 comets analyzed under each condition over n = 2 independent experiments. Mean tail moments (horizontal red bars) ± SD are shown. ≥120 comets were analyzed for each condition using the OpenComet plugin in ImageJ. Two-tailed Mann–Whitney test; p values (p < 0.0001, p < 0.0001, p = 0.0030, p < 0.0001, p < 0.0001) are indicated. Source data are provided as a Source Data file.