Lipid-Laden Macrophages Recycle Myelin to Feed Glioblastoma

Tumor-associated microglia and macrophages (TAM) make up the largest immune cell population in the glioblastoma (GBM) tumor microenvironment. Given the heterogeneity and plasticity of TAMs in the GBM tumor microenvironment, understanding the context-dependent cancer cell–TAM symbiotic interaction is crucial for understanding GBM biology and developing effective therapies. In a recent issue of Cell, Kloosterman and colleagues identified a subpopulation of glycoprotein nonmetastatic melanoma protein B^high lipid-laden microglia and macrophages (LLM) in GBM. Mesenchymal-like GBM cells help generate the LLM phenotype. Reciprocally, LLMs are epigenetically rewired to recycle myelin and transfer the lipid from myelin to cancer cells, fueling mesenchymal-like GBM progression in a liver X receptor/ABCA1-dependent manner. Together, leveraging LLMs opens new therapeutic possibilities for rewiring the metabolism-mediated tumor–TAM interaction during GBM progression.