Abstract <p>Glioblastoma multiforme (GBM) is an aggressive brain tumor characterized by metabolic plasticity and resistance to therapy. Understanding the mechanisms underlying GBM's adaptability to metabolic stress is crucial for developing effective treatments. This study investigates the role of Brain Protein I3 (BRI3) in regulating lipid metabolism and autophagy in GBM, and its potential as a therapeutic target. We performed integrative bioinformatics analysis using TCGA–GBM and CGGA datasets to identify lipophagy-related gene signatures. BRI3's function was examined through in vitro studies using GBM cell lines and patient-derived samples. Lipid metabolism and autophagy were assessed under normal and oxygen–glucose deprivation (OGD) conditions in BRI3-knockdown and control GBM cells. Bioinformatics analysis revealed a lipophagy-related gene signature associated with poor prognosis in GBM. BRI3 emerged as a key upregulated gene in GBM, correlating with altered lipid homeostasis and enhanced autophagy. In vitro studies demonstrated that BRI3 knockdown led to lipid accumulation, impaired autophagy, reduced proliferation, and increased apoptosis in GBM cells. Under OGD conditions mimicking the tumor microenvironment, BRI3-depleted cells showed compromised lipid mobilization, autophagy induction, and cell survival compared to controls. Our findings suggest BRI3 as a critical regulator of lipophagy in GBM, enhancing tumor cell resilience to metabolic stress. This study provides insights into GBM's metabolic adaptability and identifies BRI3 as a potential therapeutic target for modulating tumor cell survival in the challenging glioblastoma microenvironment.</p> Graphical Abstract <p></p>