Deubiquitinase USP33 promotes the glycolysis and growth of osteosarcoma by modifying PFKFB3 ubiquitination and degradation

Osteosarcoma (OS) is the most common malignant tumor of the bone tissue with the lowest survival rate among all pediatric cancers. OS cells grow vigorously under malnutrition; however, the mechanism by which they adapt to metabolic stress via metabolic reprogramming remains undefined. Here, we demonstrated that USP33, a member of the DUBs family, was significantly upregulated in the tissues of patients with OS compared to normal tissues. Moreover, high USP33 expression was significantly associated with poor survival. Functional assays suggested that USP33 promoted OS cell growth through the induction of aerobic glycolysis. Additionally, we confirmed that 6-phosphofructo-2-kinase/fructose-2, 6-biphosphatase 3 (PFKFB3) was critical for USP33-induced proliferation and aerobic glycolysis in OS cells, and the protein expression levels of PFKFB3 and USP33 were positively correlated in the OS tissues. Mechanistically, USP33 stabilized the expression of PFKFB3 by suppressing the ubiquitin mediated PFKFB3 degradation. Collectively, these findings reveal a mechanism by which OS cells survive in a dystrophic tumor microenvironment, with the USP33-PFKFB3 axis as a critical driver of aerobic glycolysis and OS proliferation. Furthermore, these findings reveal novel insights into the adaptation of cancer cells to metabolic stress in OS.