Fig. 2: IMPDH2 downregulation or pharmacological inhibition leads to DNA damage accumulation and G2/M arrest.
From: Nuclear IMPDH2 controls the DNA damage response by modulating PARP1 activity
A Cell cycle profile of U2OS cells using the adapted FUCCI system, with the scaled density of nuclear IMPDH2 high (top 10%, left panel) and IMPDH2 low (bottom 10%, right panel) expressing cells. B Quantification of IMPDH2 nuclear integrated intensity across the different cell cycle phases (nG1 = 635, nS = 418, nG2M = 243; unpaired two-tailed Wilcoxon test). C Representative pictures of cells in G1 or G2M phases of the cell cycle (scale bar 25 μm). D Quantification of ɣH2AX nuclear integrated intensity across the different cell cycle phases (nG1 = 751, nS = 387, nG2M = 375; unpaired two-tailed Wilcoxon test). Representative pictures (E) and quantification (F) of ɣH2AX foci (ɣH2AX orange, DAPI blue; scale bar 15 μm) in MDA-MB-231 (NT, n = 6081; sh1, n = 5534; sh2, n = 2916) and CAL-51 (NT, n = 16171; sh1, n = 7916; sh2, n = 15196) cell lines 72 h after knockdown of IMPDH2; unpaired two-tailed Wilcoxon test. Representative pictures (G) and quantification (H) of ɣH2AX foci (ɣH2AX orange, DAPI blue; scale bar 15 μm) in MDA-MB-231 cells treated with increasing amounts of MPA (72 h) or etoposide control (3 h) (MPA 0, n = 6086; MPA 2.5 μM, n = 6005, MPA 7.5 μM, n = 5018, MPA 15 μM, n = 3005; DMSO, n = 2996; ETO, n = 5230; unpaired two-tailed Wilcoxon test). Guanosine titration in MDA-MB 231 WT and IMPDH2 KO cells (WT: n0 = 10683, n6.25 = 10079, n12.5 = 10368, n25 = 10784, n50 = 9917, n100 = 9275, n200 = 8232, n400 = 7834, n800 = 7326, n1000 = 5874; KO: n0 = 2161, n6.25 = 3444, n12.5 = 4147, n25 = 7014, n50 = 8741, n100 = 7009, n200 = 7446, n400 = 6388, n800 = 6268, n1000 = 5807) with representative pictures (I) (DAPI blue, ɣH2AX orange, 53BP1 green; scale bar 10 μm) and quantification of ɣH2AX foci (J), 53BP1 foci (K) and nuclei counting (L) with the percentage relative to WT nuclei count without guanosine. All box plots indicate the median value (central line), interquartile range IQR (box boundaries) and up to 1.5*IQR beyond the box boundaries (whiskers). Source data are provided as a Source Data file.
