Large-scale CRISPRi screens link metabolic stress to glioblastoma chemoresistance

Background Glioblastoma (GBM) patients frequently develop resistance to temozolomide (TMZ), the standard chemotherapy. While targeting cancer metabolism shows promise, the relationship between metabolic perturbation and drug resistance remains poorly understood.Methods We performed high-throughput CRISPR interference screens in GBM cells to identify genes modulating TMZ sensitivity. Findings were validated using multiple GBM cell lines, patient-derived glioma stem cells, and clinical data. Molecular mechanisms were investigated through transcriptome analysis, metabolic profiling, and functional assays.Results We identified phosphoglycerate kinase 1 (PGK1) as a key determinant of TMZ sensitivity. Paradoxically, while PGK1 inhibition suppressed tumor growth, it enhanced TMZ resistance by inducing metabolic stress. This activated AMPK and HIF-1α pathways, leading to enhanced DNA damage repair through 53BP1. PGK1 expression levels correlated with TMZ sensitivity across multiple GBM models and patient samples.Conclusion sOur study reveals an unexpected link between metabolic stress and chemoresistance, demonstrating how metabolic adaptation can promote therapeutic resistance. These findings caution against single-agent metabolic targeting and suggest PGK1 as a potential biomarker for TMZ response in GBM.