Figure 1.

Unlike Bulk BM Stromal Cells, Nestin+ Niche Cells Are Preserved in Human and Murine AML and Promote Leukemogenesis

(A–D) Representative examples of immunohistochemistry for human NESTIN (brown) and human CD34 (pink) in BM samples from AML patients. CD34− AML (A), CD34+ AML ([B] and [C]), and MLL-AF9+ AML (D) show increased NESTIN+ niches (arrows) and CD34+ vessels (arrowheads). Scale bar, 10 μm (A–C), 100 μm (D).

(E) Quantification of NESTIN+ niches from (A and B) (control n = 12; MLL-AF9− AML n = 56; MLL-AF9+ AML n = 5). ^∗p < 0.05, ^∗∗p < 0.01, one-way ANOVA and Bonferroni comparisons.

(F) Scheme showing the induction of AML in primary, non-transplanted Nes-GFP mice to study BMSC changes during leukemogenesis.

(G) Fold change in the number of BM stromal cells (CD45− Ter119−CD31−) and BMSCs expressing low or high levels of Nes-GFP (NesGFPlow/high) in the BM of control (C) Nes-GFP;rtTA mice and Nes-GFP;rtTA;iMLL-AF9 (AML) mice. Numbers were normalized with the average of WT controls in each independent experiment. Mice were analyzed 8–10 weeks after inducing MLL-AF9 expression. Dots represent data from individual mice (n = 2 independent experiments). Data are mean ± SEM. Unpaired two-tailed t test.

(H) Scheme showing experimental depletion of nestin+ cells in primary, non-transplanted leukemic mice. MLL-AF9 expression (iMLL-AF9) is induced with doxycycline.

(I) Nestin+ cell depletion extends AML mouse survival. Kaplan-Meier survival curve of primary iMLL-AF9 mice in control group (black, n = 9) or after nestin+ cell depletion (red, n = 11). Logrank test.