Fig. 2: Inhibition of mitochondrial fusion targets leukemia-initiating cells in vivo.

A PDX AML cells were transduced with mCherry-tagged shRNA targeting MFN2 or OPA1, or CTL shRNAs, then transplanted to recipient NSG mice. After 10–16 weeks, the engraftment of mCherry⁺ human AML cells was analyzed quantitatively by flow cytometry and qualitatively by confocal imaging on bone marrow tissue samples. B Representative contour plots for mCherry versus side-scatter-A (SSC-A) across the experimental conditions. C Representative confocal microscopy images at 20x magnification assessing the proportion of mCherry⁺ AML cells in CTL compared to MFN2- or OPA1-depleted conditions. Scale bars = 50 μm. D Relative engraftment defined as a ratio between the output (proportion of mCherry⁺ cells after 10–16 weeks) and the input (mCherry⁺ before transplantation). Results are plotted to compare MFN2 or OPA1 to the CTL conditions. Each dot indicates the relative engraftment in single mice. Two different PDX samples were transduced with CTL or anti-MFN2, or CTL or anti-OPA1 shRNAs and each of these four conditions was transplanted to five mice. E, F PDX AML cells were transduced with mCherry-tagged CTL or anti-MFN2 shRNAs, then transplanted to primary recipient NSG mice (n = 4 for each condition). Next, human AML cells were sorted after 7 days and transplanted to secondary recipient mice (n = 7 for each condition). Relative engraftment of mCherry⁺ cells was measured 12 weeks after transplant. E Schematic representation of the assay. F Relative engraftment after 12 weeks in shCTL and shMFN2 conditions. Fold-changes (FC) between the CTL and MFN2-depleted conditions are provided. Vertical bars indicate standard deviations. ns not significant, *p < 0.05, **p < 0.01, ***p < 0.001.