UCHL3 inhibits ferroptosis by stabilizing ß-catenin and maintains stem-like properties of hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is the most common type of primary hepatic liver cancer. Dysregulated Wnt/ß-catenin activation is closely related to the progression of cancer. Nevertheless, the mechanism that sustains the abnormal expression of ß-catenin in HCC has yet to be identified. In this study, we find that UCHL3 is overexpressed in HCC tissues and correlated with ß-catenin protein level. High expression of UCHL3 is associated with poor prognosis. UCHL3 knockdown markedly reduces the protein level of ß-catenin in HCC cells. TOP-luciferase activity and ß-catenin target genes expression are also decreased upon UCHL3 depletion. We find that the ARM domain of ß-catenin is required for the interaction with UCHL3. UCHL3 increases ß-catenin protein stability via removing K48-specific poly-ubiquitin chains from ß-catenin protein. Furthermore, the depletion of UCHL3 induces ferroptosis and hinders the growth, invasion, and stem cell properties of HCC cells. These impacts could be restored by the overexpression of ß-catenin. In addition, the UCHL3 inhibitor TCID inhibits the aggressive phenotype of HCC through the degradation of ß-catenin. In general, our results indicates that UCHL3 increases the stability of ß-catenin, which in turn facilitates tumorigenesis of HCC, suggesting that targeting UCHL3 may be a promising approach for the treatment of HCC.