YAP‑mediated crosstalk between the Wnt and Hippo signaling pathways (Review).

Yes‑associated protein (YAP) acts as a transcriptional co‑activator in gene expression and cell proliferation control by binding to the transcriptional factor TEA domain (TEAD) of the Hippo signaling pathway in the nucleus, and also acts as a regulator by binding to another transcriptional co‑activator, β‑catenin of the Wnt signaling pathway. Whether YAP preferentially acts as a transcriptional co‑regulator of the activity of the Hippo signaling pathway or as a regulator in the Wnt signaling pathway depends on the cell type. Nuclear YAP upregulates the expression of β‑catenin, while cytoplasmic YAP has a negative effect on this expression. The present mini‑review focused on the important roles of YAP and further discussed the cross‑links between the Wnt and Hippo signaling pathways. The Wnt and Hippo signaling pathways are both related to the development of fibrosis or cancer. The current review discussed treatment approaches for these conditions based on the two pathways. YAP, the intersection of these two signaling pathways, has the potential to be developed as a novel treatment target, according to previous basic studies on fibroblasts and cancer cells.