Figure 3. Glycosylase deficiency suppresses telomeric 8oxoG induced replication stress.

(A-B) Number of telomeric signal-free chromatid ends (A) or fragile telomeres (B) per metaphase in cell lines transiently depleted for p53. Inset shows representative images of metaphase chromosomes scored as normal, signal free end or fragile by telo-FISH (green); pink = centromeres. Data represent mean ± s.d. from number of metaphases indicated as dots analyzed from three independent experiments, normalized to the chromosome number; two-way ANOVA; NS = not significant, **p ≤ 0.01, ****p ≤ 0.0001.

(C) Immunoblot of indicated proteins in cells untreated or treated with 20 min DL, or 20 J/m² UVC light as a positive control (WT only), and recovered 3h; pATM and pChk2 indicate phosphorylated forms; GAPDH used as a loading control.

(D) Immunoblot of indicated proteins in cells untreated or treated with 20 min DL, or 20 J/m² UVC light as a positive control (WT only), and recovered 3h; pChk1 indicates phosphorylated forms; GAPDH used as a loading control.

(C) Quantification of the percent of cells showing ≥1 telomere foci co-localized with γH2AX, 53BP1 or both 24 h after no treatment or 20 min DL. Data represent the mean ± s.d. from four independent experiments, of more than 50 nuclei analyzed per condition for each experiment; 2-way ANOVA; NS = not significant (shown only for untreated to DL comparisons), *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001.