TIGAR protein levels are down-regulated by GO-203 treatment. (A-D) U266 (A,B) and RPMI8226 (C,D) cells were left untreated, and treated with 5μM GO-203 or 5μM CP-2 each day for 3 days. Cells were harvested at the indicated times (A) or on day 3 (B-D). Lysates were immunoblotted with anti-TIGAR and anti–β-actin (A, B left, and C). TIGAR and β-actin mRNAs were amplified by RT-PCR and analyzed by agarose gel electrophoresis (B right and D). (E) KMS28PE cells were left untreated, and treated with 5μM GO-203 or 5μM CP-2 each day for 3 days. Lysates were immunoblotted with the indicated antibodies.