Figure 8. K-80003 is a Potent Inhibitor of RXRα Dependent AKT Activation.

(A) Inhibition of AKT activation by Sulindac (50 μM) or K-80003 (50 μM) in the presence of TNFα.

(B) RXRα-dependent inhibition of AKT activation by K-80003. PC3 cells transfected with RXRα or RARγ siRNA were pre-treated with K-80003 (50 μM) for 1 hr before exposed to TNFα (10 ng/ml) for 30 min. pRXRα: phosphorylated RXRα.

(C) Inhibition of RXRα/Δ80 interaction with p85α by Sulindac and K-80003. A549 cells were transfected with Flag-p85α and Myc-RXRα/Δ80, treated with Sulindac (50 μM) or K-80003 (50 μM) for 1 hr before exposed to TNFα for 30 min, and analyzed by co-immunoprecipitation using anti-Flag antibody.

(D) Induction of PARP cleavage by Sulindac or K-80003 in the presence of TNFα. ZR-75-1 cells treated with TNFα and/or Sulindac (75 μM) or K-80003 (50 μM) for 6 hr were analyzed by immunoblotting.

(E) Activation of caspase-8 by K-80003 in the presence of TNFα. Cells treated with TNFα and/or K-80003 (50 μM) were analyzed by immunoblotting.

(F) Inhibition of clonogenic survival of RXRα/1–134 cells and RXRα/Δ80 stable clones by Sulindac (25 μM) and K-80003 (25 μM).

(G) Inhibition of RXRα/Δ80 tumor growth in animals by Sulindac and K-80003. Mice (n=6) were treated intraperitoneally with corn oil, Sulindac (60 mg/kg), or K-80003 (60 mg/kg) for two weeks. Tumors were removed and measured. Error bars represent SEM.

One of three to five similar experiments is shown.

See also Figure S8.