Unraveling the Role of FOXQ1 in Colorectal Cancer Metastasis

Malignant cell transformation, invasion, and metastasis are dependent on the coordinated rewiring of gene expression. A major component in the scaffold of these reprogramming events is one in which epithelial cells lose intercellular connections and polarity to adopt a more motile mesenchymal phenotype, which is largely supported by a robust transcriptional machinery consisting mostly of developmental transcription factors. This study demonstrates that the winged helix transcription factor, FOXQ1, contributes to this rewiring process, in part by directly modulating the transcription of TWIST1, itself a key mediator of metastasis that transcriptionally regulates the expression of important molecules involved in epithelial-to-mesenchymal transition. Forced expression and RNA-mediated silencing of FOXQ1 led to enhanced and suppressed mRNA and protein levels of TWIST1, respectively. Mechanistically, FOXQ1 enhanced the reporter activity of TWIST1 and directly interacted with its promoter. Furthermore, enhanced expression of FOXQ1 resulted in increased migration and invasion in colorectal cancer cell lines, whereas knockdown studies showed the opposite effect. Moreover, using the in vivo chicken chorioallantoic membrane metastasis assay model, FOXQ1 significantly enhanced distant metastasis with minimal effects on tumor growth. (C) 2013 AACR.