NEIL1 suppresses ROS accumulation to promote temozolomide resistance and malignant progression in glioma cells

BACKGROUND: Glioma is the most common malignant primary brain tumor. Temozolomide (TMZ) is the standard first-line chemotherapy, but its efficacy is severely limited by acquired resistance. Understanding resistance mechanisms, especially beyond traditional DNA repair, is crucial for improving outcomes. METHODS: We integrated multi-database glioma transcriptomics (TCGA, GTEx, CGGA). Bioinformatics (differential expression, WGCNA, glycolipid metabolism gene screening) and machine learning (LASSO, random forest) identified key genes, focusing on the DNA glycosylase NEIL1. Its expression was assessed in U251 MG cells versus TMZ-resistant (U251 MG/TMZ) cells. Gain/loss-of-function studies (lentiviral knockdown/overexpression) and pharmacological inhibition (a 2-thioxanthine derivative, TX16) were used to evaluate NEIL1's role in proliferation (CCK-8, EdU), migration, invasion, apoptosis (TUNEL), ROS, and TMZ sensitivity (IC50). A subcutaneous nude mouse model provided in vivo validation. RESULTS: (1.2-fold), and bolstered TMZ resistance. The NEIL1 inhibitor TX16 reversed these malignant behaviors and restored TMZ sensitivity (P < 0.05), reinstating ROS-driven apoptosis. In vivo, NEIL1 promoted tumor growth, which was suppressed by TX16. CONCLUSION: NEIL1 drives glioma malignancy and TMZ resistance by mitigating oxidative stress and DNA damage, highlighting its role as a promising target to overcome chemoresistance.