Ubiquitin-specific protease 5 (USP5) is frequently overexpressed in lung adenocarcinoma (LUAD) and correlates with advanced stage and poor prognosis. This study demonstrates that USP5 binds directly to CD73 and removes K48-linked polyubiquitin chains, thereby blocking its proteasomal degradation and increasing CD73 protein stability. In contrast, the E3 ligase tripartite motif-containing protein 28 (TRIM28) promotes CD73 ubiquitination and turnover. Functionally, USP5 enhances LUAD cell proliferation, migration, invasion, and tumor growth in vivo in a CD73-dependent manner. Metabolomic profiling and Seahorse assays reveal that the USP5/CD73 axis activates PI3K/AKT/mTOR signaling and drives glycolytic reprogramming, augmenting lactate production. Moreover, this axis contributes to acquired resistance to osimertinib, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI); combined inhibition of USP5 and osimertinib synergistically induces apoptosis and suppresses tumor growth in vitro and in vivo. These findings establish USP5-mediated stabilization of CD73 as a central mechanism underlying glycolytic metabolism and osimertinib resistance in LUAD, highlighting the USP5/CD73 pathway as a promising prognostic indicator and therapeutic target for LUAD treatment.
Chen et al. (2026) studied this question.