OTUB1 inhibits autophagy-dependent ferroptosis in hepatocellular carcinoma by stabilizing p62 via non-canonical deubiquitination

Abstract

Ubiquitination plays a critical role in hepatocellular carcinoma (HCC) pathogenesis and is closely linked to ferroptosis. This study investigates the function of OTUB1, a deubiquitinase overexpressed in HCC, in regulating autophagy-dependent ferroptosis. Using integrated bioinformatics, biochemical assays, and xenograft models, we demonstrated that OTUB1 is upregulated in HCC and correlates with poor prognosis. Functionally, OTUB1 knockdown suppressed proliferation and induced ferroptosis, whereas its overexpression promoted malignancy. Mechanistically, OTUB1 competitively binds to p62/SQSTM1, thereby suppressing autophagic flux. Crucially, we identified that OTUB1 stabilizes p62 via non-canonical, D88-dependent deubiquitination by specifically removing K48-linked polyubiquitin chains. This stabilization hinders the initiation of autophagy-dependent ferroptosis. Pharmacological inhibition of autophagy abrogated the ferroptosis induced by OTUB1 knockdown. Furthermore, inhibiting OTUB1 sensitized HCC tumors to Lenvatinib, resulting in synergistic anti-tumor efficacy in vivo. Collectively, these findings reveal that OTUB1 drives HCC progression by stabilizing p62 to block autophagy-dependent ferroptosis. Targeting the OTUB1-p62 axis represents a novel therapeutic strategy to overcome drug resistance and improve outcomes in advanced HCC.