Targeting Mitochondrial Membrane Potential as A Generalized Strategy to Eradicate Leukemic Stem Cells

Heterogeneity in acute myeloid leukemias makes the development of effective therapies challenging. In the current study, we found that mitochondrial membrane potential (MMP) differs as a function of metabolism and stemness of leukemic cells. Mechanistically, MMP is regulated by mitochondrial translation, whose rate is sensitive to the availability of asparagine. Interestingly, this MMP-modulating mechanism is hijacked by leukemic cells, especially leukemic stem cells (LSCs), to elevated MMP to evade chemotherapy and thus depletion of asparagine by asparaginase chemo-sensitizes LSCs. To further evaluate the function of MMP-modulating mechanisms in disease development and drug resistance, we performed a targeted drug screen and identified Alexidine as a strong MMP-lowering agent via repressing mitochondrial translation. We revealed that Alexidine binds to cardiolipin to interfere with the inner membrane localization of mitochondrial ribosomes to inhibit mitochondrial translation. We demonstrated that Alexidine has anti-leukemic effect and is a potent chemo-sensitizer. Together, our study suggests that targeting MMP-modulating machineries is a promising approach to eradicate leukemic cells. Overall design: Total RNAs were isolated from different leukemia cell lines, AML patient samples and leukemia cell line-derived xenograft models(CDX model). Genes with a FPKM no less than 1 were included in the analysis.