Analysis of etoposide inducible SCNP DDR readouts in cell lines with characterized DDR pathway deficiencies. (A) Flow plots illustrate the gating scheme to identify live (Aqua-) non-apoptotic, healthy (cPARP-) cells for analysis of DDR responses. (B) Flow plot examples of p-DNA-PKcs, p-H2AX, p-ATM and p-BRCA1 induction in ATM+/+, ATM+/- and ATM-/- cell lines (Red: 2 h unstimulated, Blue: 2 h etoposide treated, (30 μg/mL)). (C) Shown are Log2Fold change in levels of intracellular readouts following 2 hr etoposide treatment. DDR readouts: p-ATM, p-BRCA1, p-DNA-PKcs, p-53BP1, p-p53, p-Chk2, and p-H2AX. Cell lines (Cell line panel 1, Materials and methods) are coded by color. ATM-/- cell lines (grey and back dots) consistently show lower induced values for all modulated DDR readouts measured. In contrast, ATM +/- cells (magenta dots) shows slightly lower DDR readouts vs. ATM +/+ cells for some (p-ATM, p-DNA-PKcs) but not all reaoduts in these conditions.