Fig. 2
SAMHD1 suppression sensitises AML cells to CNDAC. (A) CNDAC dose-response curves in THP-1 knockout (THP-1 KO) cells, in which the THP-1 gene was disrupted using CRISPR–Cas9, or control cells (THP-1 CTRL). Values represent means ± SD of three independent experiments. Concentrations that reduce cell viability by 50% (IC50s) ± SD are provided. (B) Representative LC-MS/MS analysis of CNDAC triphosphate (CNDAC-TP) levels in THP-1 KO and THP-1 CTRL cells. (C) Representative Western blots indicating levels of proteins involved in DNA damage response in THP-1 KO and THP-1 CTRL cells after treatment with increasing CNDAC concentrations (0, 3.2, 16, 80, 400, and 2000 nM) for 72 h. (D) Caspase 3/7 activity in THP-1 KO and THP-1 CTRL cells after treatment with increasing CNDAC concentrations (0.015, 0.9375 and 60 μM) for 24, 48, and 72 h, relative to untreated controls. Mean ± SD is provided for one representative experiment out of three using three technical replicates. p-values were determined by two-tailed Student’s t-tests (*p < 0.05; **p < 0.01; ***p < 0.001). (E) CNDAC IC50 values in AML cells after transfection with SAMHD1-siRNAs (siSAMHD1) or non-targeting control siRNAs (siCTRL). Values represent the means ± SD of three technical replicates of one representative experiment out of three. p-values were determined by two-tailed Student’s t-tests (*p < 0.05; **p < 0.01; ***p < 0.001). (F) CNDAC dose-response curves in AML cell lines treated with CNDAC in the absence or presence of VPX virus-like particles (VPX-VLPs, cause SAMHD1 depletion), or VPR virus-like particles (VPR-VLPs, negative control). Values represent the means ± SD of three technical replicates of one representative experiment out of three. (G) Representative Western Blots and LC-MS/MS analyses of CNDAC-TP levels in AML cells treated with VPX-VLPs or control VPR-VLPs