Project description:Combined gene expression and DNA occupancy profiling identifies JAK/STAT signaling as a valid therapeutic target of t(8;21) AML t(8;21) is commonly associated with acute myeloid leukemia (AML). The resulting AML1-ETO fusion proteins are involved in the pathogenesis of AML. To identify novel molecular and therapeutic targets, we performed combined gene expression and promoter occupancy profiling using a primary leukemia initiating cell-enriched population induced by AML1-ETO9a (AE9a). CD45, a negative regulator of cytokine/growth factor receptor and JAK/STAT signaling, is greatly downregulated; furthermore JAK1 and JAK2 are upregulated in these leukemia cells. Consequently, JAK/STAT signaling is enhanced in the AE9a leukemia cells. Importantly, AE9a leukemia cells are highly susceptible to perturbation of JAK/STAT signaling, and a JAK2-selective inhibitor, TG101209, effectively targets these leukemia cells in vivo, suggesting the potential efficacy of JAK2 inhibitors in treating t(8;21) AML. Wild-type or AE9a leukemic samples in triplicate.
Project description:Combined gene expression and DNA occupancy profiling identifies JAK/STAT signaling as a valid therapeutic target of t(8;21) AML t(8;21) is commonly associated with acute myeloid leukemia (AML). The resulting AML1-ETO fusion proteins are involved in the pathogenesis of AML. To identify novel molecular and therapeutic targets, we performed combined gene expression and promoter occupancy profiling using a primary leukemia initiating cell-enriched population induced by AML1-ETO9a (AE9a). CD45, a negative regulator of cytokine/growth factor receptor and JAK/STAT signaling, is greatly downregulated; furthermore JAK1 and JAK2 are upregulated in these leukemia cells. Consequently, JAK/STAT signaling is enhanced in the AE9a leukemia cells. Importantly, AE9a leukemia cells are highly susceptible to perturbation of JAK/STAT signaling, and a JAK2-selective inhibitor, TG101209, effectively targets these leukemia cells in vivo, suggesting the potential efficacy of JAK2 inhibitors in treating t(8;21) AML.
Project description:Microarray gene profilling indentified snoRNAs are downstream target of Amino Enhancer of Split (AES) and are essential for AML1-ETO9a induced leukemia. Amino Enhancer of Split (Aes) is strongly induced by leukemia oncogenes AML1-ETO, PML-RARα and PLZF-RARα. With a conditional AES knockout mouse model we showed that AES is essential for AML1-ETO9a indeced leukemia. We performed gene expression microarray using mouse primary AML1-ETO9a transformed AES wildtype and knockout and showed that snoRNAs were downregulated in AES knockout cells. We found that SnoRNA induction is a common mechanism shared by distinct oncogenes including AML1-ETO, MYC and MLL-AF9. Suppression of C/D box snoRNA complexes or deletion of several single C/D box snoRNAs inhibit clonogenic growth of leukemia cells. These findings suggest that enhancement of snoRNA levels is a critical mechanism of leukemic transformation.
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:To investigate the pathological effect of miR-126 on the progression of acute myeloid leukemia (AML) induced by AML1-ETO9a (AE9a), we conducted a series of mouse bone marrow transplantation (BMT) assays with the following groups: AE9a (primary donor cells were wild-type mouse bone marrow progenitor (i.e., lineage negative; Lin-) cells retrovirally transduced with MSCV-PIG-AE9a), AE9a+miR-126 (primary donor cells were wild-type mouse bone marrow progenitor (i.e., Lin-) cells retrovirally transduced with MSCV-PIG-AE9a-miR-126), and miR-126KO+AE9a (primary donor cells were miR-126 knockout mouse bone marrow progenitor (i.e., Lin-) cells retrovirally transduced with MSCV-PIG-AE9a), along with a control group (primary donor cells were wild-type mouse bone marrow progenitor (i.e., Lin-) cells retrovirally transduced with MSCV-PIG empty vector). The control group was only used in the primary and secondary BMT assays, whereas the three leukemic groups including AE9a, AE9a+miR-126 and miR-126KO+AE9a were used in four passages (i.e., primary, secondary, tertiary and quaternary) of BMT assays. Then, gene expression profiling was conducted with bone marrow samples collected from different groups to decipher the molecular mechanisms underlying miR-126 effects on leukemia initiation and progression and maintenance and self-renewal of leukemia stem/initiating cells.
Project description:Increasing numbers of clinical cohorts have detected CCND2 mutations in acute myeloid leukemia (AML), especially in the subtype of AML with t(8;21) translocation. As known, this AML subtype is characterized by the formation of AML1-ETO fusion gene. However, AML1-ETO fusion gene alone is not sufficient to drive leukemia development, additional mutations are required for leukemogenesis. Here, we aim to investigate whether mutated CCND2 can cooperate with AML1-ETO fusion gene to drive leukemia initiation and progression. In our previous study, the conditional AML1-ETO knock-in mouse model (AML1/ETO mouse), which represented a pre-leukemia stage as myeloproliferative neoplasm phenotype, was established. To confirm whether the AML1-ETO and CCND2 mutation can cooperate to drive leukemia, the mice transduction and transplantation model harboring both AML1-ETO and CCND2 gene (both wildtype and mutant) were established. Upon the assessment of the phenotype, biological features and survival of the mice, only the mice overexpressing the AML1-ETO and CCND2 simultaneously were eventually progressed to leukemia. Besides, compared to mice overexpressing AML-ETO gene alone, mTOR and cell cycle-related pathways were significantly enriched in mice harboring both AML1-ETO and CCND2. And the selective mTOR inhibitor, Everolimus, can reduce the leukemia burden and prolong the survival of this group of mice. In conclusion, we confirmed that introduction of the CCND2 gene into the AML/ETO pre-leukemia mice can trigger the development of leukemia. We also confirmed that CCND2 overexpression resulted in the upregulation of the mTOR pathway and inhibiting the pathway may be a therapeutic agent for this subtype of leukemia.
Project description:Fusion protein AML1-ETO resulted from t(8;21) translocation is highly related to leukemia development. We have previously shown that the expression of AE9a, a spliced form of AML1-ETO, can rapidly cause leukemia in mouse. To understand how AML1-ETO is involved in leukemia development, we used AE9a leukemia model to identify a novel AE9a interacting proteins PRMT1 (protein arginine methyltransferase 1) from primary leukemic cells expressing AE9a. To examine whether PRMT1 is involved in AE9a-mediated transcription regulation, genome wide gene expression analysis is carried out in hematopoietic cell line K562 (wild type or AE9a expressing) treated with (-) control siRNA or siPRMT1.
Project description:Fusion protein AML1-ETO resulted from t(8;21) translocation is highly related to leukemia development. We have previously shown that the expression of AE9a, a spliced form of AML1-ETO, can rapidly cause leukemia in mouse. To understand how AML1-ETO is involved in leukemia development, we used AE9a leukemia model to identify a novel AE9a interacting proteins PRMT1 (protein arginine methyltransferase 1) from primary leukemic cells expressing AE9a. To examine whether PRMT1 is involved in AE9a-mediated transcription regulation, genome wide gene expression analysis is carried out in hematopoietic cell line K562 (wild type or AE9a expressing) treated with (-) control siRNA or siPRMT1. Wild type or AE9a-expressing K562 cells with control siRNA or siPRMT1 in triplicate
Project description:Hematopoietic conditional knockout (cKO) of Phf6 in a mouse retroviral-HoxA9 AML model led to increased transplantability and accumulation of a c-Kit+ Ly6C- population that we termed the 'Leukemia Initiating Cell-Enriched' (LIC-e) population. We performed bulk ATAC-Seq on the LIC-e population sort purified 4 days after transduction of Ctrl (Vav-Cre/+, Phf6 +/Y) or cKO (Vav-Cre/+, Phf6 flox/Y) marrow retrovirally transduced with HoxA9.