New homogeneous high-throughput assays for inhibitors of β-catenin/Tcf protein-protein interactions.

The transcriptional activator β-catenin is the primary mediator of the canonical Wnt/β-catenin signaling pathway. The aberrant formation of the β-catenin/T-cell factor (Tcf) complex leads to many cancers and organ fibroses. Selective inhibition of β-catenin/Tcf protein-protein interactions represents an appealing therapeutic strategy. In this study, two new robust, homogeneous high-throughput assays, AlphaScreen and fluorescence polarization, were established to study β-catenin/Tcf interactions. These two new assays reproduce native β-catenin/Tcf interactions, quantify inhibitory potency, and are complementary with each other. The establishment of these two high-throughput screenings enables quick identification of inhibitors of β-catenin/Tcf protein-protein interactions.