JOSD1 Deubiquitinates Twist1 and Facilitates Epithelial–Mesenchymal Transition in Glioblastoma

Glioblastoma (GBM) is a lethal brain tumor where diffuse invasion and a mesenchymal phenotype drive therapy resistance. Maintaining proteostasis through ubiquitin editing is a crucial stress-adaptive mechanism in cancer, but its role in GBM invasiveness is unclear. We analyzed JOSD1 expression in clinical samples and assessed its correlation with patient survival. Gain- and loss-of-function studies in GBM cell lines were performed to evaluate the role of JOSD1 in invasion, migration, proliferation, and the regulation of epithelial-to-mesenchymal transition (EMT) markers. Protein-protein interaction, deubiquitination, and cycloheximide chase assays were used to define the mechanistic relationship between JOSD1 and Twist1. Rescue experiments with Twist1 re-expression were conducted to confirm the functional axis. JOSD1 was markedly upregulated in GBM and high expression correlated with poor patient survival. JOSD1 overexpression promoted invasion, migration, proliferation, and an EMT-like shift (decreased E-cadherin, increased N-cadherin and Vimentin), while its silencing had opposite effects. Mechanistically, JOSD1 directly bound to and deubiquitinated Twist1, preventing its proteasomal degradation and extending its protein half-life. JOSD1 depletion accelerated Twist1 turnover, and re-expression of Twist1 rescued the impaired invasiveness and growth in JOSD1-deficient cells. Conversely, Twist1 knockdown abrogated the pro-invasive effects of JOSD1 overexpression. Our findings define a JOSD1-Twist1 axis that sustains a mesenchymal, invasive phenotype in GBM by regulating Twist1 protein stability. This links ubiquitin-dependent proteostasis to GBM pathogenicity, suggesting that targeting JOSD1 may represent a therapeutic strategy for aggressive, mesenchymal GBM. Glioblastoma remains one of the most lethal human cancers, and effective strategies to block its diffuse invasion are urgently needed. Here we identify the deubiquitinase JOSD1 as a previously unrecognized driver of epithelial-mesenchymal transition and invasion in glioblastoma. JOSD1 directly binds and deubiquitinates the transcription factor Twist1, preventing its proteasomal degradation and sustaining a mesenchymal, highly motile phenotype. Genetic depletion inhibition of JOSD1 destabilizes Twist1, suppresses invasion, and attenuates tumor growth in preclinical models. Clinically, JOSD1 is markedly upregulated in glioma tissues and its high expression predicts poor patient survival. Our findings nominate the JOSD1-Twist1 axis as a druggable vulnerability for invasive glioblastoma and support future development of JOSD1-targeted therapies.