Roles of secreted frizzled-related proteins in cancer

The Wnt signaling pathway is implicated in a variety of biological processesranging from developmental cell fate to human disease.The components involvedin Wnt signaling have been under intense investigation over the last 2 decades.Aberrant canonical Wnt activation has been linked to tumor formation andinvolves activation of effector molecules or loss of tumor suppressor function.Secreted frizzled-related proteins (sFRPs) are Wnt antagonists.In recent years,accumulating evidence has suggested that sFRPs act as tumor suppressorsbecause their expression is frequently silenced in cancer by promoter hypermethyla-tion.However,sFRPs may also promote cell growth in some contexts.Here,wefocus on the known knowledge of sFRPs in tumorigenesis.