Fig. 5

SOX30 suppresses Wnt/CTNNB1 signaling by directly transcriptional inhibition of CTNNB1. a SOX30 decreased the TOP-flash reporter activity in SPC-A-1 cells, whereas not affected this activity in H520 and H2170 cells. TOP-flash or FOP-flash plasmid was co-transfected with PRL-TK and SOX30 or empty vector plasmids into the cells, and detected the transcriptional activity of Wnt/CTNNB1 signaling. Error bars indicate SEM. **, p < 0.01. The p value was obtained by Student’s t-test. b Two putative binding sites for SOX30 were predicted in CTNNB1 promoter. It was predicted using Jaspar (http://jaspar.genereg.net/) with the score threshold being 85%. c The CTNNB1 promoter was cloned into pGL3-basic luciferase reporter vector. d The luciferase reporter assays were performed using the luciferase reporter plamid linked with full-length native promoter of CTNNB1 in SPC-A-1, H520 and and H2170 cells. Error bars indicate SEM. **, p < 0.01. The p value was obtained by Student’s t-test. e The ChIP-PCR assay was used to determine whether CTNNB1 was a direct target of SOX30 in SPC-A-1, H520 and and H2170 cells