The oncogenic transcription factor FOXQ1 is a differential regulator of Wnt target genes
Giulia Pizzolato, Lavanya Moparthi, Simon Söderholm, Claudio Cantù, Stefan Koch
Abstract
The forkhead box transcription factor FOXQ1 contributes to the pathogenesis of carcinomas. In colorectal cancers, FOXQ1 promotes tumour metastasis by inducing epithelial-to-mesenchymal transition (EMT) of cancer cells. FOXQ1 may exacerbate cancer by activating the oncogenic Wnt/β-catenin signalling pathway. However, the role of FOXQ1 in the Wnt pathway remains to be resolved. Here, we report that FOXQ1 is an activator of Wnt-induced transcription and regulator of β-catenin target gene expression. Upon Wnt pathway activation, FOXQ1 synergises with the β-catenin nuclear complex to boost the expression of major Wnt targets. In parallel, we find that FOXQ1 controls the differential expression of various Wnt target genes in a β-catenin-independent manner. Using RNA sequencing of colorectal cancer cell lines, we show that Wnt signalling and FOXQ1 converge on a transcriptional programme linked to EMT and cell migration. Additionally, we demonstrate that FOXQ1 occupies Wnt-responsive elements in β-catenin target gene promoters and recruits a similar set of co-factors to the β-catenin-associated transcription factor Tcf7l1. Taken together, our results indicate a multifaceted role of FOXQ1 in Wnt/β-catenin signalling, which may drive the metastasis of colorectal cancers.