CGK062 induces β-catenin degradation through a mechanism independent of GSK-3β and dependent of β-TrCP.

<p>(A) HEK293 reporter cells were incubated with CGK062 in the presence of 20 mM LiCl. (B) HEK293 reporter cells were incubated with CGK062 in the presence of 0.75 µM BIO. In (A) and (B), after 15 h, luciferase activities were determined and reported as relative light unit (RLU) normalized to cell titer. The results are the average of three experiments, and the bars indicate standard deviations. *, <i>P</i><0.05, compared with the LiCl- or BIO-treated control group. (C) Cytosolic proteins were prepared from HEK293 reporter cells treated with either vehicle (DMSO) or increasing amounts of CGK062 in the presence of 20 mM LiCl for 15 h and then subjected to Western blotting with β-catenin antibody. (D) HEK293 cells were transfected with the Δβ-TrCP expression plasmid and then incubated with either the vehicle (DMSO) or CGK062 (25 µM) in the presence of Wnt3a CM for 15 h. Cytosolic proteins were subjected to Western blotting with β-catenin and β-TrCP antibodies. In (C) and (D), the blots were reprobed with anti-actin antibody as a loading control.