Yun SI, Kim HH, Yoon JH, Park WS, Hahn MJ, Kim HC, Chung CH, Kim KK. Ubiquitin specific protease 4 positively regulates the WNT/β-catenin signaling in colorectal cancer.
Mol Oncol 2015;
9:1834-1851. [PMID:
26189775 PMCID:
PMC5528720 DOI:
10.1016/j.molonc.2015.06.006]
[Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 06/24/2015] [Accepted: 06/25/2015] [Indexed: 12/12/2022] Open
Abstract
β-catenin is a key signal transducer in the canonical WNT pathway and is negatively regulated by ubiquitin-dependent proteolysis. Through screening of various deubiquitinating enzymes (DUBs), we identified ubiquitin specific protease 4 (USP4) as a candidate for β-catenin-specific DUB. The effects of USP4 overexpression or knockdown suggested that USP4 positively controls the stability of β-catenin and enhances β-catenin-regulated transcription. Domain mapping results revealed that the C-terminal catalytic domain is responsible for β-catenin binding and nuclear transport. Examination of colon cancer tissues from patients revealed a correlation between elevated expression levels of USP4 and β-catenin. Consistent with this correlation, USP4 knockdown in HCT116, a colon cancer cell line, reduced invasion and migration activity. These observations indicate that USP4 acts as a positive regulator of the WNT/β-catenin pathway by deubiquitination and facilitates nuclear localization of β-catenin. Therefore, we propose that USP4 is a potential target for anti-cancer therapeutics.
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