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B-Lymphoid Transcription Factors Restrict Glycolytic Energy Supply for Oncogenic Signaling

Oncogenic lesions in hematopoietic progenitor cells give rise to B-cell or myeloid malignancies. While often transformed by the same oncogenes, B-cell and myeloid leukemias markedly differ in biological and clinical characteristics. Our metabolic analyses revealed that B-cell-unlike myeloid-leukemia cells are massively restricted in their glycolytic capacity. Low glycolytic reserves in B cells resulted in a state of chronic energy depletion and engaged the energy sensor LKB1-AMPK. Myeloid cells strongly activated glucose transport through insulin receptor (INSR)-AKT signaling and lacked activity of LKB1-AMPK, reflecting energy abundance. Conversely, B-cells lacked INSR-AKT signaling and were critically dependent on LKB1-AMPK-mediated glucose uptake. Cre-mediated deletion of Lkb1 caused acute glycolytic exhaustion and cell death in B-lineage but increased glycolysis, energy levels and proliferation in myeloid leukemia. C/EBPa-mediated conversion of B-cell into myeloid identity reversed the detrimental effects of Lkb1-deletion and restored glycolysis, energy levels and survival of B→myeloid reprogrammed cells. In >80% of B-lineage leukemia cases, we found genetic lesions of transcription factors (e.g. deletion of PAX5, IKZF1, rearrangement of MLL) that caused a B→myeloid lineage shift. While previously of unknown functional significance, these lesions relieved B-cell-specific transcriptional repression of molecules that mediate glucose uptake and utilization (INSR, GLUT1, HK2, G6PD) and amplified glycolytic energy supply for transforming oncogenes. Likewise, glucocorticoid receptor (NR3C1)-mediated inhibition of glucose uptake and glycolysis was strictly dependent on a B-lymphoid transcriptional program. B→myeloid lineage conversion abolished NR3C1 expression and activity, which provides a mechanistic explanation for the empiric finding that glucocorticoids are highly active in the treatment of B-cell-but not myeloid malignancies. In conclusion, B-cell-specific restriction of glycolytic energy supply represents a previously unrecognized metabolic barrier against malignant transformation and reveals LKB1-AMPK as a novel target for the treatment of human B-lineage leukemia. Disclosures No relevant conflicts of interest to declare.