Figure 4 from Mitochondrial Transfer Rescues Respiration to Support De Novo Pyrimidine Biosynthesis and Tumor Progression

MSCs are recruited early after grafting ρ0 cells. A, Tumor tissue derived from parental and ρ0 cells, as shown, was evaluated by FCM for MSCs as a percentage of nonimmune, CD45− cells, as cells positive for Sca1 and CD90. B, Tumor tissue derived from parental and ρ0 cells on days shown was evaluated by confocal microscopy for Sca1+ and CD90+ cells following staining with relevant antibodies. DAPI was used for the detection of nuclei. C–E, Heatmap illustrating diverse mRNA expression of positive regulation of microtubule polymerization or depolymerization, negative regulation of G1–S transition of the mitotic cell cycle, and positive regulation of cell growth in parental, ρ0, ρ0 D3, ρ0 D5, and ρ0 D15 cells after 72-hour cultivation without uridine. Patterns were generated through clustering analysis of bulk RNA sequencing data. The vertical axis represents individual samples, whereas the horizontal axis delineates the various mRNA transcripts. F, MSCs isolated from mito::mKate2 mice were combined with GFP-positive ρ0 cells at 1:3 and grafted in Geltrex in Balb/c mice. After 3 days, mice were sacrificed. The tissue derived from the grafted cell mixture was placed in culture flasks, and 24 and 48 hours later, the cells were inspected by confocal microscopy for red and green fluorescence. G, Parental and ρ0 cells were grafted in Balb/c mice (106 per animal), and the tumor tissue was evaluated by FCM for the presence of cancer cells in the stroma, as the percentage of CD24+/CD49f+ (breast cancer) cells of CD45− (nonimmune) cells. H, Tumor volume was evaluated using calipers. Six mice were used for each group. The presented data reflect mean values with SEM for groups. *, P value of 0.01 to 0.05; **, P value of 0.001 to 0.01; ***, P value of 0.0001 to 0.001; ****, P < 0.0001.