PKD1 represses Wnt/β-catenin transcription activity.

<p>(A) PKD1 inhibits β-catenin/TCF transcription activity. Topflash assay was performed in LNCaP cells. Data were normalized by <i>Renilla</i> luciferase activity based on average of triple samples. Error bars represent standard deviation. Significant difference between the control and tested groups were determined by Student's t-test. (B) Overexpression of PKD1 in C4-2 cells results in inhibition of Wnt target genes. Representative results of semi-quantitative RT-PCR for Wnt/β-catenin target genes from two independent assays (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0033830#s4" target="_blank">Materials and Methods</a>). (C) β-catenin in C4-2/PKD1 cells is co-localized with TGN marker p230 (white arrows). When the cells were treated with PKD1 small molecule inhibitor CID 755763 (50 nM) for 3days, the pattern is decreased (D). Anti β-catenin antibody H102 was used to stain endogenous β-catenin (red). TGN marker p230 and nuclei were labeled green. Images represent typical results from two tests.