Fig. 5: Recurrent MH-based deletions in myeloid malignancies are the result of PARP1 mediated MMEJ repair.
From: Recurrent deletions in clonal hematopoiesis are driven by microhomology-mediated end joining
a, d Indel sequences and percentage of ASXL1 (a) and SRSF2 (d) modified alleles among the total indel alleles as assessed by deep targeted sequencing (read depth 5000X) in K562 cells following the induction of DSBs in ASXL1 (a) or SRSF2 (d) loci. LIG4 −/− K562 cells (right panels) are presented together with Wild type (WT) K562 cells that were electroporated in the presence of the DMSO vehicle, 20, 40 or 60 μM rucaparib camsylate as indicated. Allele percent of 1% (a, d) and above are shown. b, e Overall modification frequency as assessed by deep targeted sequencing (read depth 5000X) in K562 cells following the induction of DSBs in ASXL1 (b) or SRSF2 (e) loci. WT K562 cells that were electroporated in the presence of the DMSO vehicle, 20, 40 or 60 μM rucaparib camsylate, together with LIG4 −/− K562 cells are shown. c, f Percentage of the recurrent MH-based deletions among the total indel alleles following the induction of DSBs in ASXL1 (c) or SRSF2 (f) loci. WT K562 cells that were electroporated in the presence of the DMSO vehicle, 20, 40 or 60 μM rucaparib camsylate, together with LIG4 −/− K562 cells are shown. Data are presented as mean values ± SEM. n = 3 biologically independent samples. Unpaired two tailed T-test was used to determine statistical significance. (*P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001). c Vehicle vs. rucaparib 20 μM p = 0.033, vehicle vs. rucaparib 40 μM p = 0.00052, vehicle vs. rucaparib 60 μM p = 4.17 e-05, vehicle vs. LIG4 −/− p = 0.00082. f Vehicle vs. rucaparib 20uM p = 0.0015, vehicle vs. rucaparib 40 μM p = 0.00025, vehicle vs. rucaparib 60 μM p = 0.0013, vehicle vs. LIG4 −/− p = 0.037. Indel signatures are: Insertions (red), ≥5-bp deletion with flanking microhomologies (MHs) of at least 2 bp (blue), ≥5-bp deletion with flanking MHs of zero or 1 bp (green), short deletion (<5-bp) (purple) and the recurrent deletions in ASXL1 (a, b, c) SRSF2 (d, e, f) genes (orange). Source data are provided as a Source Data file.
