USP2-Mediated Deubiquitination of β-catenin Drives Colorectal Adenocarcinoma Progression and Immune Evasion.

The deubiquitinase USP2 is implicated in multiple malignancies, yet its role in colorectal adenocarcinoma (COAD) remains undefined. USP2 expression in COAD was predicted using bioinformatic tools, and verified in clinical cohort of 30 paired COAD tumors and adjacent normal tissues. HCT-116 cells carrying either stable sh-USP2 knockdown or ectopic β-catenin overexpression were subjected to CCK-8 viability, colony-forming, Transwell invasion/migration, and cycloheximide (CHX) or MG132 pulse-chase assays, while co-immunoprecipitation (co-IP), reciprocal IP, ubiquitination immunoblots and confocal immunofluorescence were employed to map the USP2-β-catenin interaction. CD8⁺ T cells isolated from healthy donors were co-cultured with HCT-116 cells to assess cytotoxicity by LDH release. Finally, subcutaneous xenografts established in nude mice and syngeneic C57 mice were monitored for 28 days, after which tumors were excised, weighed, and analysed by immunohistochemistry for β-catenin and PD-L1 expression. USP2 was markedly up-regulated in COAD tissues and cell lines and associated with poor prognosis. USP2 directly bound and deubiquitinated β-catenin, prolonging its half-life and up-regulating PD-L1. USP2 knockdown suppressed proliferation, invasion, colony formation, and immune evasion, effects reversed by β-catenin re-expression. In vivo, USP2 silencing retarded tumor growth and reduced β-catenin and PD-L1 expression. USP2 stabilizes β-catenin to drive COAD progression and immune escape; targeting the USP2 - β-catenin axis offers a promising therapeutic strategy.