Abstract 2651: Deep hypoxia and the genomic background cooperate to shape the metabolic profile of acute myeloid leukemia cells
Authors: Bruno Samantha , Pazzaglia Martina , Cerchione Claudio , Soverini Simona , Cavo Michele , Montanaro Lorenzo , Simonetti Giorgia , Martinelli Giovanni 
Published: August 2019

Abstract
Hematopoietic stem cells (HSC) and leukemic stem cells (LSC) develop in the hypoxic bone marrow (BM) niche. Hypoxia contributes to the development and maintenance of LSC and might influence chemosensitivity in acute myeloid leukemia (AML). In this study we analyzed the transcriptomic and metabolomic profile of 2 AML cell lines with diverse genomic background, in order to better understand the impact of hypoxia in AML. Gene Expression Profiling (GEP) and Liquid Chromatography-Tandem Mass Spectroscopy were performed on OCI-AML3 (FAB M4,NPM1 and DNMT3A mutations) and KASUMI-1 (FAB M2, t(8;21) and KITmutation) cell lines, after 20 hours of incubation under normoxia or hypoxia (1% O2). GEP analysis was performed by Transcriptome Analysis Console (Affymetrix), DAVID tool and Gene Set Enrichment Analysis (GSEA). Hypoxia alters the transcriptional level of 1301 and 276 genes in OCI-AML3 and KASUMI-1, respectively. Hypoxia induces MYC down-regulation in both lines, combined with increased expression of several HIF-1α-related genes (e.g. ARNT, CXCR4, S100A4). Moreover, hypoxia upregulates HIF-1α target genes associated with the glycolytic-pathway, as HK2, GPI, PFKP, PKM, LDHA, ALDOA and ENO1 (p&lt;0.01). Differentially expressed transcripts were significantly enriched for genes involved in metabolic pathways including regulation of cellular amino acid metabolic process, canonical glycolysis, gluconeogenesis, pyruvate metabolism and glycolytic process (p&lt;0.01). Conversely, gene sets related to tricarboxylic acid (TCA) cycle, oxidative phosphorylation (OxPhos), cytochrome complex assembly and mitochondrial respiratory chain were enriched in normoxia. Hypoxia forced metabolic adaptation that was dependent on the cell type. In OCI-AML3 cells, deep hypoxia induced metabolic changes associated to the Warburg effect, with increased glycolysis and low efficiency of OxPhos. The metabolic hypoxia-related profile was characterized by an increased conversion of pyruvate to lactate and alanine with high levels of fumarate and succinate, which are intermediates of the TCA cycle, elevated 2-hydroxiglutarate and glycerol 3-phospate, suggesting a reduction of energy production by OxPhos. The observed increase of glutamine levels and the reduction of glutamate, that is catabolized by TCA cycle, was associated with down-regulation of MYC expression, induced by hypoxia. Kasumi-1 showed an increase of lysolipid and fatty acid metabolism, with low impact on TCA intermediates and increased levels of alanine, glutamine and glutamate. The observed cell-line specific metabolic response to hypoxia suggests that a deep characterization of stem cells residing in the hypoxic BM niche is required in each patient. Moreover, the analysis of the metabolic profile may help define specific vulnerabilities and guide personalized therapeutic approaches.Supported by: ELN, AIL, AIRC, FP7 NGS-PTL
Note: This abstract was not presented at the meeting.
Citation Format: Samantha Bruno, Martina Pazzaglia, Claudio Cerchione, Simona Soverini, Michele Cavo, Lorenzo Montanaro, Giorgia Simonetti, Giovanni Martinelli. Deep hypoxia and the genomic background cooperate to shape the metabolic profile of acute myeloid leukemia cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2651.