Figure 3.

Colony formation potential and engraftment potential of cell subpopulations derived from patients with ALDH‐rare and ALDH‐numerous AML. (a) LTC‐IC frequencies of CD34⁺ALDH⁺ cells was highest, followed by CD34⁻ALDH⁺, CD34⁺CD38⁻ ALDH^‐ and other ALDH^‐ cells (rest of ALDH^‐) derived from patients with ALDH‐rare AML. (b) LTC‐IC frequencies of CD34⁺ALDH⁺ cells derived from patients with ALDH‐numerous AML were much lower than their counterparts derived from those with ALDH‐rare AML, but significantly higher than other populations including CD34⁺ALDH⁻ and CD34⁻ALDH⁺ cells. (c) CD34⁺ALDH⁺ cells derived from patients with ALDH‐rare AML were capable of multilineage engraftment in NSG mice (mouse tx CD34⁺ALDH⁺), while CD34⁺CD38⁻ALDH^‐ gave rise only to CD33⁺ myeloid cells (mouse tx CD34⁺CD38⁻ALDH⁻). (d) FLT3‐ITD detection revealed that engrafted cells from mice transplanted with CD34⁺ALDH⁺ cells expressed FLT3‐wild type. In contrast, FLT3‐ITD was positive in engrafted human cells of mice transplanted with CD34⁺CD38⁻ALDH⁻ cells. (e) FISH analysis confirmed the nonleukemic nature of the CD34⁺ALDH⁺ progenies with cells being trisomy 8‐negative. (f and g) for patients with ALDH‐numerous AML, AML engraftment was always found upon transplantation of CD34⁺ALDH⁺ as well as CD34⁺ALDH⁻ subsets, demonstrated by FACS and FISH analysis. Percentages of engrafted human cells with the proportions of CD33⁺, CD19⁺ and CD3⁺ cells are depicted in the FACS plots; mutated cells are marked with arrows in the FISH images. M: marker, wt: wild type, mut: mutation.