Fig. 2.

Dasatinib impairs expansion of a subset of AML CD34⁺ cells in long-term cultures. Acute myeloid leukemia CD34⁺ cells (4 × 10⁴) were sorted and plated in 12-well plates precoated with MS5 stromal cells. Cells were expanded in LTC medium supplemented with 20 ng/ml IL-3, G-CSF, and TPO. Dasatinib was added as indicated concentrations. Cultures were demi-depopulated weekly for analysis. The responses to dasatinib at 0.5 nM (n = 15) (a) and 5 nM (n = 14) (b) of all AMLs capable of long-term proliferation on stroma are shown, as compared to the growth of control group (% growth of control). The time points for cell counts indicated were at week 4/5. Cell counts indicated suspension and adherent hematopoietic cells that were separated by sorting CD45⁺ (human) cells. c–e Growth curves of three AMLs with growth reduction by dasatinib treatment are shown. Weekly cumulative cell counts represented cells in suspension except at time point of replating, where cell counts reflected suspension and adherent hematopoietic cells. The leukemic cells both in suspension and adherent layer were harvested from the coculture at weeks 4 and 7 to initiate the second and third cocultures on new MS5 stroma (AML no. 1)