Targeting USP14 sensitizes glioma to radiotherapy through exacerbated reactive oxygen species accumulation

Radiotherapy is one of the most effective treatments for glioma, but therapeutic efficacy is strongly limited due to intrinsic radioresistance, which is closely linked to reactive oxygen species. This research was designed to elucidate the role and underlying mechanisms of the deubiquitinase ubiquitin-specific protease 14 (USP14) in reactive oxygen species Accumulation and radioresistance of glioma. Bioinformatics analysis demonstrated that upregulation of USP14 was associated with tumor progression, high levels of USP14 in glioma patients were correlated with a significantly poorer prognosis. Cytological experimental results demonstrated that radiotherapy could induce increased USP14 expression. Inhibition of USP14 disrupted intracellular protein homeostasis, leading to upregulation of endoplasmic reticulum stress-related proteins thereby exacerbating endoplasmic reticulum stress. This stress response further induced substantial reactive oxygen species generation and DNA damage accumulation, ultimately synergistically enhancing the tumoricidal effect of radiotherapy. In vivo, the combined application of b-AP15 (a USP14 inhibitor) and radiotherapy elicited potent antitumor effects, marked by significant suppression of tumor growth and increased apoptotic cell death. In summary, we reveal a new regulatory axis by which USP14 governs glioma radiosensitivity through reactive oxygen species-mediated DNA damage and apoptosis, providing a promising therapeutic target and strategy for reversing clinical radioresistance.