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:AE-expressing murine BM cells treated with all-trans retinoic acid (ATRA) in semi-solid methycellulose-based cultures show an increase in self-renewal capacity whilst treatment with a specific RARa agonist NRX195183 reduces their clonogenicity. Gene expression analysis was performed to further investigate the molecular mechanisms underlying these observations. Upregulated gene sets were identified in the ATRA-treated AE BM cells. 3 C57Bl/6 AML1-ETO-stop/+/Mx-Cre+ mice (#D203, 218 and 220) were treated with polyI:C to excise the stop codon allowing AML1-ETO expression. 2-4 weeks following completion of polyI:C administration, mice were euthanised and BM cells harvested. BM cells were cultured in semi-solid methylcellulose assays with cytokines for 2 weeks; then cells were harvested, pooled and replated in suspension cultures containing cytokines and the respective treatments - DMSO (control), ATRA and the specific RARa agonist NRX195183. At the 8 hour (8H) and 24 hour (24H) timepoints, cells were harvested for RNA extraction and processing.
Project description:Transcriptome analysis by RNAseq of human CD34+ hematopoietic stem and progenitor cells transduced with empty vector control(MIT), AML1-ETO (AE), wildtype FOXO1 (F WT) or FOXO1 DNA binding deficient mutant (F DB). We find wildtype FOXO1 partially recapitulates gene signature of AML1-ETO
Project description:High-resolution proteomic analysis of acute myeloid leukemia (AML) stem cells identified phospholipase C- and Ca++-signaling pathways to be differentially regulated in AML1-ETO (AE) driven leukemia. Phospholipase C gamma 1 (Plcg1) could be identified as a direct target of the AE fusion. Genetic Plcg1 inactivation abrogated disease initiation by AE, reduced intracellular Ca++-release and inhibited AE-driven self-renewal programs. In AE-induced leukemia, Plcg1 deletion significantly reduced disease penetrance, number of leukemia stem cells and abrogated leukemia development in secondary recipient hosts. In human AE-positive leukemic cells inactivation of Plcg1 reduced colony formation and AML development in vivo. In contrast, Plcg1 was dispensable for maintenance of murine and human hematopoietic stem- and progenitor cells (HSPCs). Pharmacologic inhibition of Ca++-signaling downstream of Plcg1 resulted in impaired proliferation and self-renewal capacity in AE-driven AML. Thus, the Plcg1 pathway represents a novel specific vulnerability of AE-driven leukemia and poses an important new therapeutic target.
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:Immunoediting describes the dynamic sculpting of cancer cells to evade cancer immune control, thereby enabling the development of tumors in an immunocompetent host resulting in the outgrowth of cancer cells with reduced immunogenicity.
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