Lipidomic analysis of isolated lipid droplets reveals potential metabolic pathway differences between medulloblastoma subgroups.

Introduction: Medulloblastomas (MBs) are a highly aggressive paediatric brain tumour which is very difficult to treat. Lipid metabolism has emerged as a crucial determinant of tumour progression, metastasis and therapy resistance in MBs. Lipid droplets (LDs) are lipid-rich organelles that store neutral lipids; their biology and function remain poorly characterised within MBs. Methods: MB cells from the low-aggressive Sonic hedgehog (SHH) subgroup (DAOY, UW228-2) and the high-aggressive group 3 (G4) and group 4 (G4) subgroups (D458, D283) were treated with 80 μM oleic acid (OA), 50 μM cholesterol (Chol) or a mix to induce LD formation. LDs were isolated, and lipidomic analysis was performed. Results: No lipid species were consistently upregulated across all cell lines under any treatment condition. SHH cell lines exhibited a broad and consistent lipidomic response across all three treatments, resulting in a pronounced triacylglyceride (TAG) and cholesterol ester (CE) storage profile. The more aggressive subgroups exhibited a more selective, OA-driven phenotype, characterised by longer-chain TAG and CE species. Across all cell lines, OA produced the strongest LD expansion and metabolic separation, whereas Chol elicited a more restricted but highly subgroup-specific signature. G3/G4 Chol responses provide evidence for lipid metabolism rewiring, which could be responsible for the more aggressive phenotype. Discussion: These findings demonstrate that MB subtypes not only exhibit distinct basal lipid signatures but also engage in fundamentally different lipid remodelling in response to FA overload. These distinct lipid-handling signatures display metabolic heterogeneity across MB subgroups and suggest subtype-specific vulnerabilities. Overall, these findings position LD remodelling as a potential metabolic target of MB cells.