Effects of NL and RUX combination on the transplantable leukemogenic activity of CML CD34⁺ cells and on normal CB CD34⁺ cell engraftment. (A) Experimental design for the in vivo experiments. CML CD34⁺ cells (from 2 patients) or human CB CD34⁺ cells (from 2 subjects) were cultured for 72 hours with either NL (1 µM) or RUX (500 nM) or their combination, or media control. Following treatment, recovered cells were washed and injected intravenously into 8-week-old, sublethally irradiated (300 cGy) NSG mice (CML, 5 mice/per group; CB, 4 mice for controls; RUX, 4; NL, 5; and NL+RUX, 5). (B) The levels of human CML CD45⁺ cells, and (C) CD34⁺, CD33⁺, and CD19⁺ cells regenerated in the BM of mice transplanted with cells treated in different conditions were measured at 18 weeks. (D) The levels of BCR-ABL mRNA within the human CML CD45⁺ selected cells obtained from mouse BM at 18 weeks were evaluated by qRT-PCR and normalized to BCR mRNA expression levels. (E) The levels of human CB CD34⁺, CD33⁺, and CD19⁺ cells regenerated in the BM of mice transplanted with cells treated in different conditions were measured at 16 weeks. All data from independent experiments are presented as mean ± SEM. Significance values: *P < .05; †P < .01; ‡P < .001.