Targeting TRIM25 as a therapeutic strategy to enhance ferroptosis in glioblastoma cells

Glioblastoma (GBM) is the most common malignant brain tumor with a dismal prognosis (< 7% 5-year survival) under current first-line treatment. While inducing programmed cell death (PCD) is a promising antitumor strategy, its effectiveness in GBM remains controversial. Ferroptosis emerged as the most enriched PCD process and was highly correlated with GBM malignant progression. We performed a CRISPR-Cas9 loss-of-function screen to identify critical ferroptosis contributors. Mechanistic studies involved assessing mitochondrial function and morphology. Protein interaction and degradation pathways were investigated using immunoprecipitation and ubiquitination assays. We developed a blood-brain-barrier-penetrating genome editing delivery system, Angiopep-2-modified nanoparticles with disulfide bonds (ANPSS), loaded with Cas9/sgRNA complexes. Voltage-dependent anion channel 2 (VDAC2) was identified as a critical contributor to ferroptosis. VDAC2 overexpression induced mitochondrial dysfunction and characteristic ferroptotic mitochondrial morphology. The E3 ubiquitin ligase TRIM25 was identified as a key suppressor of VDAC2, directly interacting with it and inducing its K48-linked polyubiquitination and subsequent proteasomal degradation. In vivo, the ANPSS(sgTRIM25) system effectively targeted GBM cells, significantly promoted ferroptosis, and inhibited GBM progression. Our findings demonstrate that TRIM25 is a critical negative regulator of VDAC2-dependent ferroptosis in GBM. Targeting TRIM25 using the ANPSS(sgTRIM25) genome editing system effectively overcomes ferroptosis resistance and suppresses tumor growth, representing a viable therapeutic approach for GBM.