Targeting the deubiquitinase USP28 in cancer: navigating context-dependent mechanisms and therapeutic resistance.

Ubiquitin-specific protease 28 (USP28) is a deubiquitinating enzyme initially identified as a regulator that stabilizes p53 and c-MYC in response to DNA damage stress. Beyond its role in maintaining genomic integrity and cell cycle checkpoints, USP28 is implicated in diverse pathological processes. In various solid tumors, including lung, pancreatic, ovarian, and hepatocellular carcinomas, USP28 is markedly upregulated; it promotes proliferation, metabolic reprogramming, invasion, and therapeutic resistance by stabilizing oncoproteins such as c-Myc, STAT3, and SOX9. Conversely, in specific contexts like breast cancer and certain melanomas, USP28 deficiency drives malignant progression, revealing a context-dependent functional duality. These findings underscore the complexity of USP28 signaling and highlight its potential as a therapeutic target for precision medicine. This review summarizes the molecular characteristics and physiological functions of USP28, its context-dependent roles in neoplastic diseases, and its translational implications for targeted therapy and biomarker discovery.