Figure 6. 5-Aza-dC treatment alters response to IM treatment in K562 cells. (A) Apoptosis level was assessed in K562 cells under the following conditions: 1 μM IM, 5μM 5-Aza-dC (3 wk treatment), co-treatment, and at the absence (ctrl) of both drugs. (B) Representative histograms of Pgp expression after 5 μM 5-Aza-dC treatment after 3 wk: K562 ctrl, 5-Aza-dC –treated K562 cells and Lucena cells (used for positive control of Pgp expression). PE-isotype antibody was used as a control. The results are expressed as the mean ± SD for three independent experiments. Ctrl: control.