Wnt-5a

Wnt-5a, a member of the highly conserved Wnt protein family, is a 352 amino acid protein containing 23 conserved cysteines and contains a cysteine modified by palmitate which is essential for receptor binding and biological activity. Wnt-5a is one of the most highly investigated non-canonical Wnts and has been implicated in almost all aspects of non-canonical Wnt signaling. In terms of cancer development, Wnt-5a has, until recently, lived in the shadow of its better-characterized relatives. This was largely because of its apparent inability to transform cells or signal through the canonical beta-catenin pathway that is so important in cancer, particularly colorectal cancer. Recent work in a wide range of human tumours has pointed to a critical role for Wnt-5a in malignant progression, but there is conflicting evidence whether Wnt-5a has a tumour-promoting or -suppressing role. Emerging evidence suggests that the functions of Wnt-5a can be drastically altered depending on the availability of key receptors. Hence, the presence or absence of these receptors may go some way to explain the conflicting role of Wnt-5a in different cancers.