Enhanced Expression of ABCB1 and Nrf2 in CD133-Positive Cancer Stem Cells Associates with Doxorubicin Resistance

Figure 2

DXR resistance of different subpopulations of cells. (a) MTT assay was done to evaluate the cytotoxicity of DXR. Data are expressed as the percentile of baseline (before DXR treatment) from three independent experiments. vs. all other subpopulations. (b) Representative histograms of flow cytometry analysis show the accumulation of DXR in cells 24 hr after the treatment with 10 μM DXR, in the absence or presence of 50 μM verapamil and 200 μM BSO. The dotted vertical lines through histograms indicated the mean levels of DXR accumulation in CD44⁺CD133⁺ cells for comparing with other subpopulations of cells. The results were reproducible in three independent experiments. (c) Representative histograms of flow cytometry analysis show the expression of the ABCB1 or ABCG2 in different subpopulations of cells. Quantitative data in the histograms are presented as the mean fluorescent intensity from three independent experiments.

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