Large-scale CRISPRi screens link metabolic stress to glioblastoma chemoresistance

Abstract

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. Conclusions: Our 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.