Project description:Despite early optimism, therapeutics targeting oxidative phosphorylation (OxPhos) have faced clinical setbacks, primarily stemming from their inability to distinguish healthy from cancerous mitochondria. Herein, we describe an actionable bioenergetic mechanism unique to cancerous mitochondria inside acute myeloid leukemia (AML) cells. Unlike healthy cells which couple respiration to the synthesis of ATP, AML mitochondria were discovered to support inner membrane polarization by consuming ATP. Because matrix ATP consumption allows cells to survive bioenergetic stress, we hypothesized that AML cells may resist cell death induced by OxPhos damaging chemotherapy by reversing the ATP synthase reaction. In support of our hypothesis, targeted inhibition of BCL-2 with venetoclax abolished OxPhos flux without impacting mitochondrial membrane potential. In surviving AML cells, sustained polarization of the mitochondrial inner membrane was dependent on matrix ATP consumption. Mitochondrial ATP consumption was further enhanced in AML cells made refractory venetoclax, consequential to downregulations in both the proton-pumping respiratory complexes, as well the endogenous F1-ATPase inhibitor ATP5IF1. In treatment-naive AML, ATP5IF1 knockdown was sufficient to drive venetoclax resistance, while ATP5IF1 overexpression impaired F1-ATPase activity and heightened sensitivity to venetoclax. Collectively, our data identify matrix ATP consumption as cancer-cell intrinsic bioenergetic vulnerability actionable in the context of mitochondrial damaging chemotherapy.
Project description:Acute myeloid leukemia (AML) is an aggressive blood cancer with poor prognosis. We performed a comprehensive proteogenomic analysis of bone-marrow biopsies from 252 uniformly treated AML patients to elucidate the molecular pathophysiology of AML in order to inform future diagnostic and therapeutic approaches. In addition to in-depth quantitative proteomics, our analysis included cytogenetic and mutation profiling, and RNA sequencing. This identified five proteomic AML subtypes, each reflecting specific biological features spanning genomic boundaries. Two of these subtypes were correlated with patient outcome, but none exclusively associated with specific genomic aberrations. Remarkably, one subtype (Mito-AML), which was only captured in the proteome, was characterized by high expression of mitochondrial proteins and showed poor outcome, with reduced remission rate and shorter overall survival upon treatment with intensive induction chemotherapy. Functional analyses revealed that Mito-AML is metabolically wired towards stronger complex Idependent respiration and is more responsive to treatment with the BCL2-inhibitor venetoclax.
Project description:Acute myeloid leukemia study. Supplementary Table 1: Clinical, morphological, cytogenetic and molecular genetic information on 116 AML patient samples. Supplementary Table 2: Summary of the distribution of clinical and molecular genetic characteristics within the AML sample set. Supplementary Table 3: Fluorescence ratios of the 6,283 well-measured and variably-expressed genes. Supplementary Table 4: Clinical and laboratory characteristics of normal karyotype predominant subtypes I and II. Supplementary Table 5: Supervised analysis of group-specific gene expression signatures. Supplementary Table 6: Gene-expression outcome class predictor. Supplementary Table 7: Multivariate proportional hazards analysis. Keywords: other