Effect of 17-AAG on HL-60 cell types. (A) 17-AAG treatment does not down-regulate Bcl-2 or Bcl-xL proteins. HL-60/Neo, HL-60/Bcl-2, and HL-60/Bcl-xL cells were treated with 1.0 μM 17-AAG for 48 hours. Cells were harvested, and cell lysates were used to determine Bcl-2 and Bcl-xL levels by Western blot analysis. As the loading control, β-actin was used. (B) Ectopic overexpression of Bcl-2 or Bcl-xL in HL-60 cells confers resistance against 17-AAG—induced apoptosis. HL-60/Neo, HL-60/Bcl-2, and HL-60/Bcl-xL cells were exposed to 0.1, 0.25, 0.5, 1.0, and 5.0 μM 17-AAG for 48 or 96 hours. Following these treatments, treated and untreated cells were stained with annexin V, and the percentages of positively stained cells were quantitated by flow cytometry. Values represent the mean ± standard error (SE) of 3 independent experiments.
