Effects of rottlerin on endogenous LRP6 degradation. PC-3 cells were incubated with 10 μg/ml of cycloheximide in the presence of rottlerin (2 μM) or vehicle for 0, 3, 6, 10 or 24 h. Cells were then harvested, and the level of endogenous human LRP6 (210 kDa for mature form) was examined by Western blotting. Samples were also probed with anti-actin antibody to verify equal loading. Lower panel: the pixels for each band were measured, normalized and plotted. Data are mean values of three independent experiments with the SD values indicated by error bars. *P < 0.05, **P < 0.01 versus corresponding control value.