GADD45g overexpression represses HR DNA repair pathway. (A) Volcano plots of normalized gene expression in Molm-13 cells with or without Dox treatment as analyzed by RNA-seq. (B) Gene Ontology (GO) functional enrichment analysis of the RNA-seq data. Upregulated gene- enriched GO terms are represented by red, and downregulated gene-enriched GO terms are blue. (C) GSEA plot showing the enriched genes signature associated with HR in Molm-13 cells upon GADD45g overexpression. The normalized enrichment score (NES) and P values are shown. (D) qRT-PCR analysis of key HR genes including RAD51, BRCA1, and BRCA2 expression in THP-1, U937, HL60, and Molm-13 cells upon GADD45g overexpression. Data are presented as the fold change in gene expression relative to the negative control group, which is considered as 1. (E) Representative IF micrographs (left) of RAD51 foci in Molm-13 cells with or without Dox-induced GADD45g overexpression from 3 independent experiments, and quantification (right) of RAD51 foci (red) in nuclei (blue) per cell. Scale bar, 5 μm. (F) Representative micrographs (left) of the neutral comet assays for THP-1 and Molm-13 cells with or without Dox-induced GADD45g overexpression from 3 independent experiments, and quantification of tail-moments in comet assays (right). Representative IF micrographs showing γH2AX foci in Molm-13 cells, primary BMMNCs from patients with AML, and MNCs from human CB with or without GADD45g overexpression from 3 independent experiments (G), and quantification of the γH2AX foci per cell (H). Scale bar, 5 μm. (I) The efficiency of HR-mediated repair of I-SceI–induced DSB in THP-1 and Molm-13 cells transduced with pLV-GADD45g-mCherry (GADD45g) or lentiviral empty control vector (Control). Data are presented as the mean ± SD of ≥3 independent experiments, and comparisons were evaluated by using the 2-tailed Student t test. *P < .05, **P < .01, ***P < .001, ****P < .0001. DAPI, 4′,6-diamidino-2-phenylindole; NS, not significant.