Expression of Ring Finger Protein 43 Gene in Cancers

RNF43(ring finger protein 43) is a member of proteins of Goliath and Godzilla families, which bears the characteristic sequence of an ubiquitin ligase and of a trans-membrane region, encoding E3 ubiquitination kinase and with the activity of E3 ubiquitin protein ligase. RNF43 has attracted much attention in the study of Wnt/β-catenin signaling pathway because of its high structural homology with ZNRF3(zinc and ring finger protein 3). RNF43 inhibits Wnt/β-catenin signalling by ubiquitinating Frizzled receptor and targeting it to the lysosomal pathway for degradation. Loss of function of RNF43 results in decrease or lack of degradation of Frizzled with enhancement of Wnt/β-catenin signalling pathway. The scavenging effect of RNF43 on Wnt membrane receptor is mediated by its binding to membrane receptors, so many studies have suggested that RNF43 is localized on the cell membrane. However, some scholars believe that RNF43 is located in the nucleus, even without specific organelles, but scattered in the cytoplasm. The abnormal expression and mutation of RNF43 gene are thought to be closely related to the occurrence and development of many cancers. Now there are many studies about the relationship between RNF43 gene and cancers, involving serrated colorectal lesions, gastric adenocarcinomas, pancreatic cystic lesions and adenocarcinomas, hepatic carcinoma, ovarian mucinous tumours, endometrial adenocarcinomas, neuroglioma and so on. Although large part of studies support that RNF43 is a tumor suppressor gene, a small number of studies suggest that RNF43 might be an oncogene. We make a review about the basic structure, location, biological function and expression of RNF43 gene in some cancers.