Fig. 6: Astrocytes are the predominant mitochondrial donors for ρ⁰ GBM cells.

To determine which brain resident cell type is the donor of mitochondria for cancer cells, in vitro co-culture experiments with two cell types isolated from adult mouse brain were carried out (A). Co-cultures of neural cells and GL261 ρ⁰ GFP⁺ cells were assessed by fluorescent confocal microscopy after 48 h (B) and by flow cytometry after 24 h (C). mtDNA levels were detected in parental and ρ⁰ cells, and in ρ⁰ cells after their 72-h co-culture with potential neural donor cells (D). Horizontal transfer of mitochondria from astrocytes in vivo was confirmed by confocal microscopy (F) using the inducible MitoTag mice model as visualised (E). CC AST – co-culture with astrocytes, CC MIC - co-culture with microglia, TAM – tamoxifen, i.p. – intraperitoneal, P – postnatal day, Aldh1l1 – aldehyde dehydrogenase 1l1.