Abstract
Glioblastoma (GBM), the most aggressive central nervous system (CNS) malignancy, currently lacks curative therapeutic options. While immunotherapy has revolutionized treatment for many cancers, GBM remains refractory to immune-based interventions due to the absence of effective immunotherapeutic targets. Here, through CRISPR screening, we identify Niemann-Pick C1-like 1 (NPC1L1) as a previously unrecognized key driver of GBM progression. Mechanistically, NPC1L1 modulates cholesterol metabolism to concurrently enhance tumor cell stemness and suppress CD8+ T-cell activation, thus inducing tumor progression. Notably, combined treatment with ezetimibe (NPC1L1 inhibitor) and anti-PD-1 antibody elicited potent antitumor activity in GBM orthotopic mouse models. Collectively, these findings establish NPC1L1 as a critical regulator of GBM pathogenesis, underscoring the translational potential of targeting NPC1L1-mediated cholesterol metabolism for developing novel GBM immunotherapies.