Dynamic alteration of hematopoiesis-supportive gene expression in BM stromal cells during AML development. Gene expression was determined by qPCR on freshly FACS-sorted BM SCA1⁺CD51⁺ MSCs, SCA1⁻CD51⁺ MPCs, and CD31⁺ ECs from recipient mice at different time points posttransplantation of MLL-AF9⁺ AML cells or normal KIT⁺ HSPCs. Data are presented as mean values of duplicate or triplicate qPCR measurements from 3 to 4 independent sorting experiments. Statistical differences were determined using an unpaired parametric 1-sided Student t test and Pearson or Spearman correlation. (A) Relative mRNA expression of hematopoiesis-supportive genes and mesenchymal lineage–associated genes in BM MSCs 21 days after transplantation of AML cells. (B) Relative expression of hematopoiesis-supportive genes and mesenchymal lineage–associated genes in BM MPCs 21 days after transplantation of AML cells. (C) Correlation between AML cell engraftment and relative expression of the hematopoiesis-supportive genes in recipient BM MPCs after transplantation of the AML cells.