Figure 5.

In vivo administration of AZD1480 reduces primary human AML but not normal stem cells in NSG mice. (A) AML or CB mononuclear cells were transplanted into NSG mice. After 6 to 10 weeks, engraftment was confirmed, and mice were treated with AZD1480 (50 mg/kg) or vehicle daily for 2 weeks and evaluated for human cell engraftment. In 1 experiment, secondary transplant of BM cells to NSG mice was performed, and human cell engraftment was evaluated after 8 weeks. (B) Human CD45⁺ cells in BM of mice engrafted with AML cells (AML566, AML600, AML666, AML866, and AML1274) following 2 weeks of treatment with AZD1480 or DMSO. The pSTAT3 and pSTAT5 expression levels for each sample are indicated in the figure. (C-E) Pooled AML CD34⁺ cells from 2 patients (AML 404 and 755) were transplanted into NSG mice that were subsequently treated with AZD1480 or vehicle for 2 weeks, following which BM cells from primary recipient mice were transplanted in limiting dilutions (1.6 × 10⁶, 0.8 × 10⁶, 0.2 × 10⁶ cells per mouse × 8 mice each) into secondary recipient mice, and human CD45⁺ cells in PB and BM (1.8 × 10⁶ only) were evaluated after 8 weeks. (C) Human AML CD45⁺ cells and expression of differentiation markers on engrafted CD45⁺ cells in BM of primary recipients following AZD1480 or DMSO treatment. (D) Human CD45⁺ cells in PB cells of secondary recipients 8 weeks after limiting dilution transplant of BM cells from primary recipients. (E) Stem cell frequency in AZD1480- and DMSO-treated mice calculated using Poisson statistics. (F) Engraftment of human AML CD45⁺ cells and expression of differentiation markers on engrafted CD45⁺ cells in BM of secondary recipients at 8 weeks after transplant. (G) Human CD45⁺ cells in BM of mice engrafted with CB cells and treated for 2 weeks with AZD1480 or DMSO. (H) Expression of differentiation markers on human CB CD45⁺ cells in BM after AZD1480 or DMSO treatment. (I) Engraftment of human CD45⁺ cells and expression of differentiation markers on engrafted CD45⁺ cells in BM of secondary recipients at 8 weeks after transplantation of BM cells from AZD1480-treated and control mice. Results represent mean ± SEM. Significance values: *P < .05, **P < .01, ***P < .001.