The bioenergenetic and metabolic profile of developing tumours changes dynamically to meet changing growth requirements and complex adaptive interactions with cells of the microenvironment. We have recently shown that metastatic melanoma and breast carcinoma cell models with mtDNA damage acquire intact mitochondria from adjacent normal cells, and that this transfer is associated with respiration recovery and tumour growth. This novel discovery adds a new layer of complexity to cancer cell biology that directly impinges on adaptive remodelling following mitochondrial damage and DNA-damaging treatment regimens. To investigate intercellular mitochondrial transfer in the brain, we developed a mouse glioma model devoid of mtDNA (GL261ρo) and therefore glycolytic and auxotrophic for uridine and pyruvate. When injected intracranially into syngeneic mice, tumour growth occurred between 87 and 126 days compared with 26-29 days for parental GL261 cells. Cell lines from these tumours contained mtDNA polymorphisms of the recipient mouse, showed enhanced respiration recovery and similar tumorigenicity to parental GL261 cells when passaged intracranially. Coculture of GL261ρo with stromal cells derived from bone chips of mice transgenic for a mitochondrially-imported red fluorescent protein (mitoDsRed) showed mitochondrial uptake by GL261ρo cells. Furthermore, a GFP neonatal astrocyte cell line without mtDNA (GFP NeoAstrocyte ρo) acquired mitochondria from mitoDSRed bone chip-derived stromal cells, but stable lines could not be established. When injected intracranially, GFP NeoAstrocyte ρo cells survived less than 7 days. We conclude that normal cells in the brain can transfer mitochondria to glioma cells without mtDNA restoring cell respiration and tumorigenicity.