Targeting fatty acid metabolism to abrogate differentiation block in pre-leukemia induced by AML1-ETO
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ABSTRACT: To gain the underlying insight into the functional impact of AML1-ETO expressed in HSPCs, RNA-seq was performed on purified LT-HSCs and GMPs from the bone marrow (BM) of both AML1-ETO expressed (AML1/ETO) and Wild-Type (control) C57 mice. Our work suggested that AML1-ETO resulted in impaired hematopoietic reconstitution and increased self-renewal ability.The oxidative phosphorylation and glycolysis decreased significantly in AML1/ETO LT-HSCs accompanied by increased HSC quiescence and reduced cell cycling. Furthermore, it was observed that HSCs expressing AML1-ETO exhibited an increased requirement for fatty acids when they differentiated.
Project description:To gain the underlying insight into the functional impact of AML1-ETO expressed in hematopoietic stem cells and progenitors (HSPCs), we employed single-cell transcriptome sequencing to elucidate the characteristics of purified Lin-c-kit+ cells (HSPCs) from the bone marrow (BM) of both AML1-ETO expressed (AML1/ETO) and Wild-Type (control) C57 mice.
Project description:U937 AML cells that express an inducible AML1-ETO construct under the control of the tetracycline promoter. Microarrays used to discover an AML1-ETO signature for a GE-HTS screen to identify AML1-ETO modulators.
Project description:Somatic mutations in acute myeloid leukemia (AML) are acquired sequentially and hierarchically. First, pre-leukemic mutations, such as t(8;21) that encodes AML1-ETO, are acquired within the hematopoietic stem cell (HSC) compartment, while signaling pathway mutations, including K-RAS activating mutations, are late events acquired during transformation of leukemic progenitor cells and rarely detectable in HSCs. This raises the possibility that signaling pathway mutations are detrimental to clonal expansion of pre-leukemic HSCs. To address this hypothesis we here used conditional genetics to introduce Aml1-ETO and K-RasG12D into murine HSCs, either individually or in combination. In the absence of activated Ras, Aml1-ETO expression conferred a competitive advantage to HSCs. However, activated K-Ras had a marked detrimental effect on Aml1-ETO expressing HSCs, leading to loss of both phenotypic and functional HSCs. Cell cycle analysis revealed a loss of quiescence in HSCs co-expressing Aml1-ETO and K-RasG12D, accompanied by an enrichment in E2F and Myc target gene expression and depletion of HSC self-renewal-associated gene expression. These findings provide a mechanistic basis for the observed absence of KRAS, and potentially other, signaling mutations in the pre-malignant HSC compartment.
Project description:In an effort to identify novel drugs targeting fusion-oncogene induced acute myeloid leukemia (AML), we performed high-resolution proteomic analysis. In AML1-ETO (AE) driven AML we uncovered a deregulation of phospholipase C (PLC) signaling. We identified PLCgamma 1 (PLCG1) as a specific target of the AE fusion protein which is induced after AE binding to intergenic regulatory DNA elements. Genetic inactivation of PLCG1 in murine and human AML inhibited AML1-ETO dependent self-renewal programs, leukemic proliferation, and leukemia maintenance in vivo. In contrast, PLCG1 was dispensable for normal hematopoietic stem- and progenitor cell function. These findings are extended to and confirmed by pharmacologic perturbation of Ca++-signaling in AML1-ETO AML cells, indicating that the PLCG1 pathway poses an important therapeutic target for AML1-ETO positive leukemic stem cells.
Project description:Kasumi-1 AML cells that were transfected in triplicate with AML1-ETO or luciferase siRNA constructs by either Amaxa nucleofection or Biorad siLentFect and incubated for 96 hours. Microarrays used to discover an AML1-ETO signature for a GE-HTS screen to identify AML1-ETO modulators.
Project description:Compare the gene expression profile among human CD34+ cord blood cells infected with MIGR1, MIGR1-AML1-ETO or MIGR1-AML1-ETO∆NHR1 AML1-ETO promotes the self-renewal of human hematopoietic stem/progenitor cells (HSPCs). We found deletion of NHR1 domain abrogates AML1-ETO induced expasion of HSPCs.
Project description:Approximately 20% of Acute Myelogenous Leukemia (AML) cases carry the t(8;21) translocation, which involves the AML1 and ETO genes, and express the resulting AML1/ETO fusion protein that functions as a transcriptional repressor by recruiting NCoR/SMRT/HDAC complexes to DNA. We used ChIP-chip to identify the determinants of AML1/ETO binding on a contiguous DNA region (chromosome 19). AML1/ETO binding regions are characterized by a specific sequence signature that includes the presence of the consensus binding sites for the AML1 and HEB transcription factors. We therefore assessed the binding patterns of AML1 and HEB on chromosome 19. A specific chromatin modification (tri-methylation of lysine 4 on histone 3 = 3MetK4) was also studied in U937 cells expressing AML1/ETO in order to correlate the identified binding profiles with active transcription sites. Keywords: ChIP-chip
Project description:Approximately 20% of Acute Myelogenous Leukemia (AML) cases carry the t(8;21) translocation, which involves the AML1 and ETO genes, and express the resulting AML1/ETO fusion protein that functions as a transcriptional repressor by recruiting NCoR/SMRT/HDAC complexes to DNA. We used microarrays to identify human promoters bound by AML1/ETO in U937 cells. Keywords: ChIP-chip
Project description:Approximately 20% of Acute Myelogenous Leukemia (AML) cases carry the t(8;21) translocation, which involves the AML1 and ETO genes, and express the resulting AML1/ETO fusion protein that functions as a transcriptional repressor by recruiting NCoR/SMRT/HDAC complexes to DNA. We used microarrays to identify genes differentially expressed in U937 cells expressing AML1/ETO compared to vector transfected U937 cells. Keywords: Transcriptional regulation