Fig. 6

AZD1775 abrogates the intra-S-phase checkpoint and augments cell death induced by cytarabine. A A TP53 isogenic NALM6 cell line model was treated for 24 h with AZD1775 (200 nM), AraC (15 nM), or their combination and subjected to dual cell cycle and pHH3 (mitotic cells) analysis using flow cytometry. Data are representative of three independent experiments. 2N DNA content indicates cells in G₀ or G₁ phase. 4N DNA content indicates cells in either G₂ or M phase. Mitotic index was determined for cells with 4N and < 4N DNA content. Boxes indicate pHH3⁺ populations. Error bars show mean ± SD of at least three independent experiments. Top, PI alone; bottom, pHH3/PI. B Immunoblot of apoptotic and cell cycle markers in NALM6 cells treated for 24 h with AZD1775 (200 nM), AraC (15 nM), or their combination. Images are representative of three independent experiments. C Immunoblot of apoptotic and cell cycle markers in three relapsed PDX samples treated with respective IC50s of AZD1775, AraC, or their combination for 24 h. N = 1 for each respective sample. In B and C, ɑ-tubulin was used as loading control