Figure 1.

PP blocks Wnt/β-catenin signaling. (A) Molecular structure of PP. (B) RPMI-8226 and LP1 cells were treated with PP at the indicated concentrations for 48 h, and western blot analysis was performed with whole-cell lysates. RPMI-8226 cells were transfected with (C) plasmids (empty vector or β-catenin) or (D) shRNAs (scramble or β-catenin-targeting). The cells were treated with the indicated concentration of PP, cell lysates were subjected to western blot analysis and the degree of cell death was determined using a trypan blue exclusion assay. *P<0.05, **P<0.01, ***P<0.001; β-catenin vs. empty vector, shβ-catenin #1 or shβ-catenin #2 vs. Scramble, respectively. shRNA, short hairpin RNA; PP, pyrvinium pamoate; p-GSK3β, phosphorylated glycogen synthase kinase 3β; PARP, poly (ADP-ribose) polymerase.