Western blot analysis was carried out as previously described (Tomimaru et al., 2013a (link)). In brief, immunoblots were probed with primary antibodies generated against β-catenin, β-actin (Cell Signaling Technology, Beverly, MA), cyclin D1, and PCNA (Santa Cruz Biotechnology, Inc., Santa Cruz, CA) and detected with HRP-labeled anti-mouse or anti-rabbit IgG (Amersham Pharmacia Biotech, Buckinghamshire, UK) using SuperSignal West Femto Maximum Sensitivity Substrate (Thermo Scientific, Rockford, IL). Positive signals were captured by the Image analyzer LAS-1000 plus (Fujifilm, Tokyo, Japan) and the band intensity of protein was determined using Image Gauge version 3.45 (Fujifilm).