Figure 1

CD34⁺ KG1a and Kasumi-1cells were insensitive to DNR. (A) KG1a, Kasumi-1 and U937 cells were stained with PE-conjugated CD34 antibody and subjected to flow cytometry to determine the purity of CD34⁺ cells. (B, C) These three cell lines were treated with different concentrations of DNR for 48 h. MTT assay (B) was performed as described in "Methods" and apoptosis (C) was assessed by Annexin V/PI assays. Cells in the lower right quadrant represent early apoptosis and those in the upper right quadrant represent late apoptosis. The graph displays the means ± SD of three independent experiments. * p < 0.05, ** p < 0.01, *** p < 0.001 (compared with control).