PLOD1 Catalytic Activity Stabilizes ENO1 by Limiting FBXW7-dependent Degradation to Promote Glycolysis and TMZ Resistance in Glioblastoma.

Acquired resistance to temozolomide (TMZ) remains a major therapeutic challenge in glioblastoma (GBM), with metabolic reprogramming emerging as a critical driver of treatment failure. Procollagen lysyl hydroxylase 1 (PLOD1) is identified as a key regulator of adaptive metabolic remodeling in TMZ-resistant GBM. Elevated PLOD1 promotes a hyper-glycolytic phenotype by maintaining the stability of the glycolytic enzyme alpha-enolase (ENO1). Mechanistically, PLOD1 catalytic activity increases an ENO1-associated hydroxylation signal, promotes ENO1 stability, and limits FBXW7-dependent ubiquitination and proteasomal degradation. Structural and functional analyses reveal that the central Ndst region of PLOD1 mediates substrate interaction, whereas its catalytic domain is required for ENO1 stabilization and downstream metabolic regulation. Clinically, PLOD1 and ENO1 expression levels are positively correlated in GBM specimens, and their co-expression is associated with unfavorable patient outcomes. In xenograft models, inhibition of the PLOD1-ENO1 axis suppresses tumor progression and enhances TMZ responsiveness. These findings establish the PLOD1-FBXW7-ENO1 regulatory axis as a critical mediator of GBM metabolic adaptation and therapeutic resistance, highlighting its potential as a prognostic biomarker and therapeutic target.