GO-203 treatment increases β-F1-ATPase expression and reduces ATP levels. (A-D) U266 (A,C) and RPMI8226 (B,D) cells were left untreated, and treated with 5μM GO-203 or 5μM CP-2 each day for 3 days. The GO-203–treated cells were also incubated in the presence of 5mM NAC for the last 2 days. Lysates from U266 (A) and RPMI8226 (B) cells were immunoblotted with the indicated antibodies. Lysates from U266 (C) and RPMI8226 (D) cells were analyzed for intracellular ATP levels. The results are expressed as relative ATP levels (mean ± SD of 3 determinations) compared with that obtained for the control.