A direct protein-protein interaction is involved in the suppression of β-catenin transcription by retinoid X receptor α in colorectal cancer cells

Abstract

Using both mammalian two-hybrid assay in vivo and immunoprecipitation in vitro we found that retinoid X receptor α (RXRα) directly interacted with β-catenin and suppressed β-catenin transcriptional activity and protein expression in colorectal cancer cells. But, reduction of RXRα by small interfering RNA upregulated β-catenin transcriptional activity and protein expression. However, gain- or loss- expression of β-catenin did not affect RXRα. Therefore, our data provided the first evidence that RXRα directly interacted with β-catenin and regulated β-catenin transcription, which provides important information for developing novel strategies in colorectal cancer prevention by targeting RXRα-β-catenin signaling.