The role of Wnt signaling in cancer and stem cells.

The Wingless-Int (Wnt) signaling pathway has been widely investigated in recent years. Initially, its role regulating cell proliferation and survival during embryogenesis aroused the interest of researchers. Later, the focus was placed on the link between aberrant Wnt pathway activation and human cancer. The improper function of Wnt signaling components can lead to aberrant cell proliferation and cancer. Mutations in the adenomatous polyposis coli and beta-catenin genes first implicated Wnt signaling in carcinogenesis. Over time, a wealth of evidence has indicated that amplification or inhibition of other components might also play a role in human cancers. In addition, Wnt signaling pathways also play a crucial role in normal tissue regeneration and stem cell self-renewal, raising the possibility of controlling immature tumor stem cells.