SOX21 suppresses glioblastoma growth by repressing AP-1 activity.

Rrapaj E, Yuan J, Kurtsdotter I, Misyurin V, Baselli GA, Holmberg J, Persson O, Bergsland M, Muhr J

Cell Death Dis 17 (1) 191 [2026-01-31; online 2026-01-31]

Treatment-resistant glioblastoma stem and precursor cells (GPCs) drive glioblastoma (GBM) growth and recurrence. Thus, targeting the molecular machinery that sustains GPCs in an undifferentiated and self-renewing state is a promising therapeutic strategy. The transcription factor SOX21 effectively suppresses the tumorigenic capacity of GPCs, but the mechanism by which SOX21 impedes GPC features is unknown. By engineering patient-derived GPCs with a transgenic TetOn system we show that SOX21 expression induces an anti-tumorigenic transcriptional program, aligning with clinical data demonstrating a positive correlation between SOX21 levels and improved GBM patient survival. Induced SOX21 expression in GPCs within pre-established GBM reduces their capacity to sustain tumor growth and significantly extends the survival of the orthotopically transplanted mice. Mechanistically, SOX21 functions as a tumor suppressor by binding a large set of AP-1-targeted chromatin regions, leading to epigenetic repression of AP-1-activated genes. Consistently, the anti-tumorigenic activities of SOX21 are largely replicated by AP-1 inhibitors, which decrease GPC proliferation and survival, while overexpression of the AP-1 family member, c-JUN, counteracts these effects. Our findings identify SOX21 as a key regulator that prevents GPC malignancy by targeting and repressing an AP-1-driven, tumor-promoting gene expression program. These results highlight SOX21-regulated pathways as promising therapeutic targets for GBM.

NGI Short read [Service]

NGI Stockholm (Genomics Production) [Service]

National Genomics Infrastructure [Service]

PubMed 41620461

DOI 10.1038/s41419-026-08442-5

Crossref 10.1038/s41419-026-08442-5

pii: 10.1038/s41419-026-08442-5


Publications 9.5.1