Effect of S100A8 overexpression in MSCs on the growth and drug resistance of human AML cells in vitro. (A) Growth curve of Kasumi-1 cells cocultured with MSCs overexpressing S100A8 or control MSCs (n = 3). (B) Effects of S100A8 overexpression on the cell cycle of Kasumi-1; flow diagram (left) and statistical plots (right; n = 3). (C) S100A8 overexpression affects apoptosis in Kasumi-1 cells, with flow representative plots (left) and statistical plots (right; n = 3). (D) Effect of S100A8 overexpression on etoposide (2 μM) resistance in Kasumi-1 cells, with flow diagram (left) and statistical plots (right; n = 3). (E) Flow of patient-derived xenograft (PDX) modeling after coculture of patient-derived AML cells with MSCs. (F) PB white blood cell (WBC) counts in PDX mice with S100A8 overexpression vs the control group (n = 4-5). (G) Percentage of BM leukemia cells of PDX mice in the S100A8 overexpression and control group (n = 4-5). (H) The percentage of SP leukemia cells in PDX mice with S100A8 overexpression vs the control group (n = 4-5). ∗P < .05; ∗∗P < .01; ∗∗∗P < .001. Ctrl, control; MACS, magnetic-activated cell sorting; ns, not significant; NSG, NOD scid gamma mice.