Expression of MSC-derived S100A8 under leukemic state. (A) Transcriptome sequencing data compare the expression of cytokines in MSC-derived AML mice with rapid vs slow disease progression. (B) Flowchart of coculture of patient-derived BM MSC with leukemic cells Kasumi-1. (C) Identify the adipose differentiation capacity of MSC by Oil Red O staining. (D) Identifying the osteogenic differentiation capacity of MSC by Alizarin red staining. (E) Flow plots of representative fluorescence intensity of S100A8 in MSC coculture with Kasumi-1 and control MSC. (F) Mean fluorescence intensity (MFI) of S100A8 in MSCs after coculture with Kasumi-1 cells (n = 3). (G) Expression of S100A8 in BM MSCs from MLL-AF9 mice and normal mice (n = 5). (H-I) Representative immunofluorescence images of human BM sections from a healthy donor and a patient with AML stained for CD271 (red), S100A8 (green), and DAPI (4′,6-diamidino-2-phenylindole; blue), along with quantitative analysis of S100A8 expression based on confocal microscopy (scale bars, 10 μm; n = 6). ∗∗∗P < .001. Ctrl, control; MNC, mononuclear cells.