White matter injury fuels early progression of glioblastoma

Glioblastoma (GBM) is the most aggressive and devastating primary brain cancer in adults. Most GBMs are diagnosed at an advanced stage with therapy resistance, posing a major obstacle to understanding the tumor microenvironment (TME) at the earliest stages of disease development. A precise characterization of early-stage GBM and its TME could provide critical insights into tumor progression and inform new therapeutic strategies. In a recent issue of Nature, Clements and colleagues demonstrated that white matter (WM) injury, induced by early tumor cells, constitutes a key TME factor driving GBM progression. Using somatic mouse models, patient-derived xenografts (PDXs), and human tissues, they showed that early glioma cells preferentially infiltrate WM tracts, inducing SARM1-mediated Wallerian degeneration (WD) that propagates into distal WM regions. Remarkably, WM injury induced by axonal transection significantly accelerated GBM progression at distal sites, whereas this effect was abolished by Sarm1 knockout, confirming that axonal injury followed by WD drives distal tumor progression. Collectively, these findings reveal a previously unrecognized evolutionary process in GBM development and highlight potential targets for therapeutic intervention.