Figure 47.

The canonical (yellow background) and non-canonical (red background) Wnt/β-catenin signaling pathways are related to mechanical elements and actions responsible for cell polarization, migration and tissue organization. Blue background stands for membrane bound receptors. β-catenin is a major player and is permanently created and degraded by the APC complex. It is important for linking the cytoskeleton to the cell membrane and to neighboring cells but also as a gene transcription factor. If it is over-expressed or if APC is not working properly developmental genes are activated and the cell is less adhesive and the epithelial-mesenchymal transition is induced with cell migration and proliferation. These are features of malignant tumors. The Wnt pathway is further directly linked to pathways controlling the activity and structure of the cytoskeleton: Rac, Cdc42, and Rho. It was recently discovered that IPGAP1 has a major regulatory function for actin and MT cytoskeleton. This is also the case for the APC-Asef complex. The illustration combines different sources as indicated by numbers on a white background. 1: [560], 2: [561], 3:[559], 4: [562,563], 5: [564].