Wnt/β-catenin signaling reporter assay

Transcriptional activity assays were performed using the Luciferase Assay System (Genepharma, China) according to the manufacturer’s instructions^{37 (link)}. Briefly, cells were transfected with siRNAs targeting β-catenin or the scramble control. Cells were co-transfected with the M50 Super 8× TOP Flash or M51 Super 8× TOP Flash by Lipofectamine 3000 after 24 h post transfection. In some of the experiments, cells were also co-transfected with TMEM170B expression vector and miR-27a mimic or inhibitor. The luciferase activity of each sample was normalized against Renilla luciferase activity to monitor transfection efficiency. Twenty-four hours after transfection of plasmids, cells were lysed and luciferase activity was measured using the dual-luciferase reporter (DLR) assay Kit (Promega). Firefly and Renilla luciferase activities were determined using a luminometer and normalized.