Yabushita, T. | Search bioRxiv

bioRxiv2023

Group comparison based on genetic information reveals lineage-specific therapeutic vulnerabilities in acute myeloid leukemia

Cancer is a genetic disease with specific mutations or fusions. Therapies targeting cancer cell-specific essential genes are expected to have efficient anticancer effects with fewer side effects. To explore such cancer cell-specific vulnerabilities, we established a two-group comparison system to predict essential genes in each cancer subtype using the data from the Cancer Dependency Map (DepMap). We applied this analytical method to acute myeloid leukemia (AML) and identified PCYT1A and BCL2L1 as a specific vulnerability in MLL-rearranged AML and TP53-mutated AML, respectively. Interestingly, further investigation revealed that PCYT1A is in fact a critical regulator in monocytic AML including those with MLL-rearrangements, and BCL2L1 is essential in acute erythroid leukemia in which TP53 is frequently mutated. These results highlighted the importance of cell of origin, rather than the genetic aberrations alone, to identify subtype-specific vulnerabilities in AML. The DepMap-based two-group comparison approach could accelerate the discovery of subtype-specific therapeutic targets in diverse cancers.

cancer biology↗

bioRxiv2023

Context-Dependent Modification of PFKFB3 in Hematopoietic Stem Cells Promotes Anaerobic Glycolysis and Ensures Stress Hematopoiesis

Metabolic pathways are plastic and rapidly change in response to stress or perturbation. Current metabolic profiling techniques require lysis of many cells, complicating the tracking of metabolic changes over time after stress in rare cells such as hematopoietic stem cells (HSCs). Here, we aimed to identify the key metabolic enzymes that define differences in glycolytic metabolism between steady-state and stress conditions in HSCs and elucidate their regulatory mechanisms. Through quantitative 13C metabolic flux analysis of glucose metabolism using high-sensitivity glucose tracing and mathematical modeling, we found that HSCs activate the glycolytic rate-limiting enzyme phosphofructokinase (PFK) during proliferation and oxidative phosphorylation (OXPHOS) inhibition. Real-time measurement of adenosine triphosphate (ATP) levels in single HSCs demonstrated that proliferative stress or OXPHOS inhibition led to accelerated glycolysis via increased activity of PFKFB3, the enzyme regulating an allosteric PFK activator, within seconds to meet ATP requirements. Furthermore, varying stresses differentially activated PFKFB3 via PRMT1-dependent methylation during proliferative stress and via AMPK-dependent phosphorylation during OXPHOS inhibition. Overexpression of Pfkfb3 induced HSC proliferation and promoted differentiated cell production, whereas inhibition or loss of Pfkfb3 suppressed them. This study reveals the flexible and multilayered regulation of HSC glycolytic metabolism to sustain hematopoiesis under stress and provides techniques to better understand the physiological metabolism of rare hematopoietic cells. Key PointsO_LICombined isotope tracing, mathematical modeling, and single cell ATP analysis enable high-resolution evaluation of blood cell metabolism. C_LIO_LIUnder stress, HSCs quickly accelerate glycolysis to meet ATP demands and maintain hematopoiesis via context-dependent PFKFB3 activation. C_LI

cell biology↗