Figure 3. Cell death and DNA repair mediated by PARP1 are suppressed in aneuploid cells by PARP1 downregulation.

(A) PARP1 levels in near-diploid hCEC clones with PARP1 knockdown. (B) Viability of cells from (A) after H₂O₂. Mean ± SD of 9 fields (C) PARP1 levels in the acute aneuploidy (TP53WT hCEC) with PARP1 overexpression. Dashed lines indicate spliced lanes. (D) Viability of cells from (B) after H₂O₂. (E) PARP1 levels in aneuploid hCEC clones with PARP1 overexpression. (F) Viability of cells from (E) after H₂O₂. (G) Viability after H₂O₂ treatment with PARP1 knockdown, PARP1 overexpression, or both. (H) PARP1 levels (left) and H₂O₂-induced cell viability (right) in hCECs with doxycycline-inducible PARP1 overexpression. (I) Viability after H₂O₂ (40 μM) with PARP1or TIMELESS overexpression or both. (J) Viability after H₂O₂ in hCEC clones with NMN pretreatment (180 μM, 24h). (K) Viability after MNNG treatment (62.5 μM, 24 hours) in hCEC clones with control or PARP1 overexpression. (L) Viability after UV (50 J/m² + 5-day release) in hCEC clones. Average viability indicated below dashed line. (M) γH2AX before and after H₂O₂ (50 μM, 1h) in hCEC clones ± PARP1 overexpression. Left: images (scale bar, 10 μm). Right: violin plots showing median and quartiles (>460 cells/condition). R0/R6: 0 or 6h post-H₂O₂. All p-values in Table 3. γH2AX-negative threshold set at ~80% for untreated clones; percentages shown below X-axis. One-way ANOVA with Dunnett’s test (B); with Tukey’s test (G, I, J, K, L). Unpaired t-test (D, F, H). Kruskal-Wallis one-way ANOVA with Dunnett’s test (M).