α7 nicotinic acetylcholine receptor agonist attenuates allergen-induced immediate nasal response in murine model of allergic rhinitis.

The expression of nicotinic acetylcholine receptor (nAChR) subunits on various immune cells suggests their involvement in allergic rhinitis. However, how exactly they contribute to this pathogenesis is not yet confirmed. Our present study examined the therapeutic potential of GTS-21, an α7 nAChR agonist, for treating allergic rhinitis by employing its mouse models. GTS-21 treatment reduced allergen-induced immediate nasal response in ovalbumin (OVA)-sensitized model. However, nasal hyperresponsiveness or eosinophil infiltration elicited in either the OVA-sensitized or T helper 2 cell-transplanted model was not affected by GTS-21. GTS-21 did not alter allergen-induced passive cutaneous anaphylaxis response in anti-dinitrophenyl IgE-sensitized mice. This evidence implies GTS-21's potential to alleviate allergic rhinitis without perturbing T cells or mast cells.

MBTD1 preserves adult hematopoietic stem cell pool size and function.

Mbtd1 (mbt domain containing 1) encodes a nuclear protein containing a zinc finger domain and four malignant brain tumor (MBT) repeats. We previously generated Mbtd1-deficient mice and found that MBTD1 is highly expressed in fetal hematopoietic stem cells (HSCs) and sustains the number and function of fetal HSCs. However, since Mbtd1-deficient mice die soon after birth possibly due to skeletal abnormalities, its role in adult hematopoiesis remains unclear. To address this issue, we generated Mbtd1 conditional knockout mice and analyzed adult hematopoietic tissues deficient in Mbtd1. We observed that the numbers of HSCs and progenitors increased and Mbtd1-deficient HSCs exhibited hyperactive cell cycle, resulting in a defective response to exogenous stresses. Mechanistically, we found that MBTD1 directly binds to the promoter region of FoxO3a, encoding a forkhead protein essential for HSC quiescence, and interacts with components of TIP60 chromatin remodeling complex and other proteins involved in HSC and other stem cell functions. Restoration of FOXO3a activity in Mbtd1-deficient HSCs in vivo rescued cell cycle and pool size abnormalities. These findings indicate that MBTD1 is a critical regulator for HSC pool size and function, mainly through the maintenance of cell cycle quiescence by FOXO3a.

Generation of reporter mice for detecting the transcriptional activity of nuclear factor of activated T cells.

Nuclear factor of activated T cells (NFAT) is a transcription factor essential for immunological and other biological responses. To develop analyzing system for NFAT activity in vitro and in vivo, we generated reporter mouse lines introduced with NFAT-driven enhanced green fluorescent protein (EGFP) expressing gene construct. Six tandem repeats of -286 to -265 of the human IL2 gene to which NFAT binds in association with its co-transcription factor, activator protein (AP)-1, was conjunct with thymidine kinase minimum promoter and following EGFP coding sequence. Upon introduction of the resulting reporter cassette into C57BL/6 fertilized eggs, the transgenic mice were obtained. Among 7 transgene-positive mice in 110 mice bone, 2 mice showed the designated reporter mouse character. Thus, the EGFP fluorescence of CD4+ and CD8+ T cells in these mice was enhanced by stimulation through CD3 and CD28. Each of phorbol 12-myristate 13-acetate (PMA) and ionomycin (IOM) stimulation weakly but their combined stimulation strongly enhanced EGFP expression. The stimulation-induced EGFP upregulation was also observed following T cell subset differentiation in a different manner. The EGFP induction by PMA + IOM stimulation was more potent than that by CD3/CD28 stimulation in helper T (Th)1, Th2, Th9, and regulatory T cells, while both stimulation conditions displayed the equivalent EGFP induction in Th17 cells. Our NFAT reporter mouse lines are useful for analyzing stimulation-induced transcriptional activation mediated by NFAT in cooperation with AP-1 in T cells.

Re-evaluation of over-the-counter histamine H1-receptor antagonists based on their effects on murine models of allergen-induced nasal hyperresponsiveness.

T cells play an essential role in the development of allergen-induced nasal hyperresponsiveness (NHR), a pathophysiological response in allergic rhinitis. The effects of histamine H1-receptor antagonists (antihistamines) on murine NHR models were investigated. Intragastric epinastine, fexofenadine, and loratadine administration suppressed allergen-induced immediate nasal response but not NHR in immunized mice. Regardless of the alleviation of stimulation-induced Th2 cytokine expression by loratadine and desloratadine in vitro, allergen-induced NHR and nasal eosinophil infiltration in Th2 cell-transferred mice were unaffected by loratadine in vivo. This influence on T cell-mediated NHR was excluded from the pharmacological effects of antihistamines.

DDX41 expression is associated with tumor necrosis in clear cell renal cell carcinoma and in cooperation with VHL loss leads to worse prognosis.

BACKGROUND: Histologic tumor necrosis (TN) is a well-established independent prognostic indicator in patients treated surgically for clear cell renal cell carcinoma (ccRCC). However, the precise mechanisms by which TN alters disease progression remain unknown. The DEAD-box protein DDX41, a member of a large family of helicases, has been characterized as a pattern recognition receptor against an array of double-stranded (ds)DNA produced from bacteria, dsDNA viruses, and nearby cells that have released dsDNA fragments through necrosis. We hypothesized that DDX41 expression may be upregulated in ccRCC with TN, leading to worse prognosis. METHODS: Relationship between the presence of TN and DDX41 expression were examined using The Cancer Genome Atlas data sets or using ccRCC samples in our institution. Further, the molecular functions of DDX41 were investigated with human ccRCC cells. RESULTS: The presence of TN was significantly associated with the upregulation of mRNA and protein expression of DDX41 in the 2different patient cohorts with ccRCC. In addition, the mRNA and protein expression levels of DDX41 revealed a worse prognosis. In vitro analyses with ccRCC cells revealed that DDX41 expression promotes tumor-promoting activity. Furthermore, VHL loss, 1of the most common features in ccRCC, was shown to play an extremely important role in increasing the expression of the CXCL family in DDX41-expressing ccRCC, leading to the acquisition of a worse malignant phenotype. CONCLUSIONS: DDX41 expression is associated with TN in ccRCC and leads to a worse prognosis in cooperation with VHL loss.

Th17-Dependent Nasal Hyperresponsiveness Is Mitigated by Steroid Treatment.

Th17 cells are implicated in allergic inflammatory diseases, including allergic rhinitis (AR), though the effect of steroids on Th17 cell-dependent nasal responses is unclear. Herein, we investigated a nasal inflammation model elicited by allergen provocation in mice infused with Th17 cells and its responsiveness against steroid treatment. We transferred BALB/c mice with Th17 cells, which were differentiated in vitro and showed a specific reaction to ovalbumin (OVA). We challenged the transferred mice by intranasal injection of OVA and to some of them, administered dexamethasone (Dex) subcutaneously in advance. Then, we assessed immediate nasal response (INR), nasal hyperresponsiveness (NHR), and inflammatory cell infiltration into the nasal mucosa. The significant nasal inflammatory responses with massive neutrophil accumulation, INR, and NHR were induced upon allergen challenge. Allergen-induced INR and NHR were significantly suppressed by Dex treatment. This study suggested the effectiveness of steroids on Th17 cell-mediated nasal responses in AR.

Expression and Function of Nicotinic Acetylcholine Receptors in Induced Regulatory T Cells.

A contribution of the cholinergic system to immune cell function has been suggested, though the role of nicotine and its receptors in T cells, especially regulatory T (Treg) cells, is unclear. We herein investigated the expression and function of nicotinic acetylcholine receptors (nAChRs) in murine-induced Treg (iTreg) cells. Upon differentiation of naive BALB/c T cells into iTreg cells and other T-cell subsets, the effect of nicotine on cytokine production and proliferation of iTreg cells was examined. The expression of nAChRs and its regulatory mechanisms were comparatively analyzed among T-cell subsets. Stimulation-induced transforming growth factor-ß1 (TGF-ß1) production of iTreg cells was suppressed by nicotine, whereas interleukin (IL)-10 production and proliferation was not affected. α2-, α5-, α9-, and ß2-nAChRs were differentially expressed in naive, Th1, Th2, Th9, Th17, and iTreg cells. Among these cell types, the α9-nAChR was particularly upregulated in iTreg cells via its gene promoter, but not through tri-methylation at the 4th lysine residue of the histone H3-dependent mechanisms. We conclude that the immunoregulatory role of Treg cells is modified by the cholinergic system, probably through the characteristic expression of nAChRs.

Suppressive effect of dexamethasone on murine Th9 cell-mediated nasal eosinophilic inflammation.

BACKGROUND: Th9 cells have been implicated in the development of allergic inflammation, though its contribution to allergic rhinitis and the effect of steroid on Th9 cell-mediated nasal responses are unclear. OBJECTIVE: In this study, allergen-induced nasal inflammatory responses and their steroid responsiveness were investigated in ovalbumin (OVA)-specific Th9 cell-transferred mice. METHODS: BALB/c mice were transferred with in vitro-differentiated Th9 cells and challenged by intranasal injection of OVA with or without subcutaneous administration of dexamethasone (Dex). Then, the infiltration of inflammatory cells in the nasal mucosa and nasal hyperresponsiveness (NHR) was assessed. RESULTS: The significant NHR accompanied by nasal infiltration of eosinophils as well as allergen-specific T cells was induced in Th9 cell-transferred mice upon allergen challenge. These responses were strongly suppressed by the treatment with Dex. CONCLUSION: The participation of Th9 cells in the pathogenesis of allergic rhinitis was suggested.

L-type amino acid transporter 1 inhibitor suppresses murine Th2 cell-mediated bronchial hyperresponsiveness independently of eosinophil accumulation.

BACKGROUND: The activation of Th2 cells that play a pivotal role in the development of allergic eosinophilic inflammation is regulated by an L-type amino acid transporter (LAT) 1. However, the contribution of LAT1 to the pathogenesis of Th2 cell-mediated airway inflammation has not been investigated. OBJECTIVE: In this study, we investigated the effect of a LAT1 inhibitor, JPH203, on Th2 cell-mediated airway eosinophilic inflammation. METHODS: BALB/c mice were transferred with ovalbumin (OVA)-specific Th2 cell and challenged by corresponding allergen with or without administration of JPH203. Then, the infiltration of inflammatory cells including eosinophils and allergen-specific Th2 cells in the lungs and bronchial hyperresponsiveness (BHR) was assessed. RESULTS: Inflammatory responses in the lungs with massive accumulation of eosinophils and BHR were induced in Th2 cell-transferred mice upon challenge with OVA. The treatment with JPH203 significantly suppressed the allergen-induced BHR but not eosinophil infiltration. The infused Th2 cells were also accumulated in the lungs upon allergen challenge, though the response was not affected by JPH203 treatment. CONCLUSION: JPH203 suppressed Th2 cell-mediated BHR through the mechanisms independently of the lung accumulation of eosinophils and Th2 cells.

UTX maintains the functional integrity of the murine hematopoietic system by globally regulating aging-associated genes.

Epigenetic regulation is essential for the maintenance of the hematopoietic system, and its deregulation is implicated in hematopoietic disorders. In this study, UTX, a demethylase for lysine 27 on histone H3 (H3K27) and a component of COMPASS-like and SWI/SNF complexes, played an essential role in the hematopoietic system by globally regulating aging-associated genes. Utx-deficient (UtxΔ/Δ) mice exhibited myeloid skewing with dysplasia, extramedullary hematopoiesis, impaired hematopoietic reconstituting ability, and increased susceptibility to leukemia, which are the hallmarks of hematopoietic aging. RNA-sequencing (RNA-seq) analysis revealed that Utx deficiency converted the gene expression profiles of young hematopoietic stem-progenitor cells (HSPCs) to those of aged HSPCs. Utx expression in hematopoietic stem cells declined with age, and UtxΔ/Δ HSPCs exhibited increased expression of an aging-associated marker, accumulation of reactive oxygen species, and impaired repair of DNA double-strand breaks. Pathway and chromatin immunoprecipitation analyses coupled with RNA-seq data indicated that UTX contributed to hematopoietic homeostasis mainly by maintaining the expression of genes downregulated with aging via demethylase-dependent and -independent epigenetic programming. Of note, comparison of pathway changes in UtxΔ/Δ HSPCs, aged muscle stem cells, aged fibroblasts, and aged induced neurons showed substantial overlap, strongly suggesting common aging mechanisms among different tissue stem cells.

Association of aberrant ASNS imprinting with asparaginase sensitivity and chromosomal abnormality in childhood BCP-ALL.

Karyotype is an important prognostic factor in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL), but the underlying pharmacogenomics remain unknown. Asparaginase is an integral component in current chemotherapy for childhood BCP-ALL. Asparaginase therapy depletes serum asparagine. Normal hematopoietic cells can produce asparagine by asparagine synthetase (ASNS) activity, but ALL cells are unable to synthesize adequate amounts of asparagine. The ASNS gene has a typical CpG island in its promoter. Thus, methylation of the ASNS CpG island could be one of the epigenetic mechanisms for ASNS gene silencing in BCP-ALL. To gain deep insights into the pharmacogenomics of asparaginase therapy, we investigated the association of ASNS methylation status with asparaginase sensitivity. The ASNS CpG island is largely unmethylated in normal hematopoietic cells, but it is allele-specifically methylated in BCP-ALL cells. The ASNS gene is located at 7q21, an evolutionally conserved imprinted gene cluster. ASNS methylation in childhood BCP-ALL is associated with an aberrant methylation of the imprinted gene cluster at 7q21. Aberrant methylation of mouse Asns and a syntenic imprinted gene cluster is also confirmed in leukemic spleen samples from ETV6-RUNX1 knockin mice. In 3 childhood BCP-ALL cohorts, ASNS is highly methylated in BCP-ALL patients with favorable karyotypes but is mostly unmethylated in BCP-ALL patients with poor prognostic karyotypes. Higher ASNS methylation is associated with higher L-asparaginase sensitivity in BCP-ALL through lower ASNS gene and protein expression levels. These observations demonstrate that silencing of the ASNS gene as a result of aberrant imprinting is a pharmacogenetic mechanism for the leukemia-specific activity of asparaginase therapy in BCP-ALL.

Kdm6a Deficiency Activates Inflammatory Pathways, Promotes M2 Macrophage Polarization, and Causes Bladder Cancer in Cooperation with p53 Dysfunction.

PURPOSE: Epigenetic deregulation is deeply implicated in the pathogenesis of bladder cancer. KDM6A (Lysine (K)-specific demethylase 6A) is a histone modifier frequently mutated in bladder cancer. However, the molecular mechanisms of how KDM6A deficiency contributes to bladder cancer development remains largely unknown. We hypothesized that clarification of the pathogenic mechanisms underlying KDM6A-mutated bladder cancer can help in designing new anticancer therapies. EXPERIMENTAL DESIGN: We generated mice lacking Kdm6a in the urothelium and crossed them with mice heterozygous for p53, whose mutation/deletion significantly overlaps with the KDM6A mutation in muscle-invasive bladder cancer (MIBC). In addition, BBN (N-butyl-N-(4-hydroxybutyl) nitrosamine), a cigarette smoke-like mutagen, was used as a tumor-promoting agent. Isolated urothelia were subjected to phenotypic, pathologic, molecular, and cellular analyses. The clinical relevance of our findings was further analyzed using genomic and clinical data of patients with MIBC. RESULTS: We found that Kdm6a deficiency activated cytokine and chemokine pathways, promoted M2 macrophage polarization, increased cancer stem cells and caused bladder cancer in cooperation with p53 haploinsufficiency. We also found that BBN treatment significantly enhanced the expression of proinflammatory molecules and accelerated disease development. Human bladder cancer samples with decreased KDM6A expression also showed activated proinflammatory pathways. Notably, dual inhibition of IL6 and chemokine (C-C motif) ligand 2, upregulated in response to Kdm6a deficiency, efficiently suppressed Kdm6a-deficient bladder cancer cell growth. CONCLUSIONS: Our findings provide insights into multistep carcinogenic processes of bladder cancer and suggest molecular targeted therapeutic approaches for patients with bladder cancer with KDM6A dysfunction.

Expression of mutant Asxl1 perturbs hematopoiesis and promotes susceptibility to leukemic transformation.

Additional sex combs like 1 (ASXL1) is frequently mutated in myeloid malignancies and clonal hematopoiesis of indeterminate potential (CHIP). Although loss of ASXL1 promotes hematopoietic transformation, there is growing evidence that ASXL1 mutations might confer an alteration of function. In this study, we identify that physiological expression of a C-terminal truncated Asxl1 mutant in vivo using conditional knock-in (KI) results in myeloid skewing, age-dependent anemia, thrombocytosis, and morphological dysplasia. Although expression of mutant Asxl1 altered the functions of hematopoietic stem cells (HSCs), it maintained their survival in competitive transplantation assays and increased susceptibility to leukemic transformation by co-occurring RUNX1 mutation or viral insertional mutagenesis. KI mice displayed substantial reductions in H3K4me3 and H2AK119Ub without significant reductions in H3K27me3, distinct from the effects of Asxl1 loss. Chromatin immunoprecipitation followed by next-generation sequencing analysis demonstrated opposing effects of wild-type and mutant Asxl1 on H3K4me3. These findings reveal that ASXL1 mutations confer HSCs with an altered epigenome and increase susceptibility for leukemic transformation, presenting a novel model for CHIP.

Acquired expression of CblQ367P in mice induces dysplastic myelopoiesis mimicking chronic myelomonocytic leukemia.

Chronic myelomonocytic leukemia (CMML) is a hematological malignancy characterized by uncontrolled proliferation of dysplastic myelomonocytes and frequent progression to acute myeloid leukemia (AML). We identified mutations in the Cbl gene, which encodes a negative regulator of cytokine signaling, in a subset of CMML patients. To investigate the contribution of mutant Cbl in CMML pathogenesis, we generated conditional knockin mice for Cbl that express wild-type Cbl in a steady state and inducibly express CblQ367P , a CMML-associated Cbl mutant. CblQ367P mice exhibited sustained proliferation of myelomonocytes, multilineage dysplasia, and splenomegaly, which are the hallmarks of CMML. The phosphatidylinositol 3-kinase (PI3K)-AKT and JAK-STAT pathways were constitutively activated in CblQ367P hematopoietic stem cells, which promoted cell cycle progression and enhanced chemokine-chemokine receptor activity. Gem, a gene encoding a GTPase that is upregulated by CblQ367P , enhanced hematopoietic stem cell activity and induced myeloid cell proliferation. In addition, Evi1, a gene encoding a transcription factor, was found to cooperate with CblQ367P and progress CMML to AML. Furthermore, targeted inhibition for the PI3K-AKT and JAK-STAT pathways efficiently suppressed the proliferative activity of CblQ367P -bearing CMML cells. Our findings provide insights into the molecular mechanisms underlying mutant Cbl-induced CMML and propose a possible molecular targeting therapy for mutant Cbl-carrying CMML patients.

Propagation of trimethylated H3K27 regulated by polycomb protein EED is required for embryogenesis, hematopoietic maintenance, and tumor suppression.

Polycomb repressive complex 2 (PRC2) catalyzes the monomethylation, dimethylation, and trimethylation of histone H3 Lys27 (H3K27) and acts as a central epigenetic regulator that marks the repressive chromatin domain. Embryonic ectoderm development (EED), an essential component of PRC2, interacts with trimethylated H3K27 (H3K27me3) through the aromatic cage structure composed of its three aromatic amino acids, Phe97, Trp364, and Tyr365. This interaction allosterically activates the histone methyltransferase activity of PRC2 and thereby propagates repressive histone marks. In this study, we report the analysis of knock-in mice harboring the myeloid disorder-associated EED Ile363Met (I363M) mutation, analogous to the EED aromatic cage mutants. The I363M homozygotes displayed a remarkable and preferential reduction of H3K27me3 and died at midgestation. The heterozygotes increased the clonogenic capacity and bone marrow repopulating activity of hematopoietic stem/progenitor cells (HSPCs) and were susceptible to leukemia. Lgals3, a PRC2 target gene encoding a multifunctional galactose-binding lectin, was derepressed in I363M heterozygotes, which enhanced the stemness of HSPCs. Thus, our work provides in vivo evidence that the structural integrity of EED to H3K27me3 propagation is critical, especially for embryonic development and hematopoietic homeostasis, and that its perturbation increases the predisposition to hematologic malignancies.

Maintenance of the functional integrity of mouse hematopoiesis by EED and promotion of leukemogenesis by EED haploinsufficiency.

Polycomb repressive complex 2 (PRC2) participates in transcriptional repression through methylation of histone H3K27. The WD-repeat protein embryonic ectoderm development (EED) is a non-catalytic but an essential component of PRC2 and its mutations were identified in hematopoietic malignancies. To clarify the role(s) of EED in adult hematopoiesis and leukemogenesis, we generated Eed conditional knockout (Eed(Δ/Δ)) mice. Eed(Δ/Δ) mice died in a short period with rapid decrease of hematopoietic cells. Hematopoietic stem/progenitor cells (HSPCs) were markedly decreased with impaired bone marrow (BM) repopulation ability. Cell cycle analysis of HSPCs demonstrated increased S-phase fraction coupled with suppressed G0/G1 entry. Genes encoding cell adhesion molecules are significantly enriched in Eed(Δ/Δ) HSPCs, and consistently, Eed(Δ/Δ) HSPCs exhibited increased attachment to a major extracellular matrix component, fibronectin. Thus, EED deficiency increases proliferation on one side but promotes quiescence possibly by enhanced adhesion to the hematopoietic niche on the other, and these conflicting events would lead to abnormal differentiation and functional defect of Eed(Δ/Δ) HSPCs. In addition, Eed haploinsufficiency induced hematopoietic dysplasia, and Eed heterozygous mice were susceptible to malignant transformation and developed leukemia in cooperation with Evi1 overexpression. Our results demonstrated differentiation stage-specific and dose-dependent roles of EED in normal hematopoiesis and leukemogenesis.

Identification of cooperative genes for E2A-PBX1 to develop acute lymphoblastic leukemia.

E2A-PBX1 is a chimeric gene product detected in t(1;19)-bearing acute lymphoblastic leukemia (ALL) with B-cell lineage. To investigate the leukemogenic process, we generated conditional knock-in (cKI) mice for E2A-PBX1, in which E2A-PBX1 is inducibly expressed under the control of the endogenous E2A promoter. Despite the induced expression of E2A-PBX1, no hematopoietic disease was observed, strongly suggesting that additional genetic alterations are required to develop leukemia. To address this possibility, retroviral insertional mutagenesis was used. Virus infection efficiently induced T-cell, B-cell, and biphenotypic ALL in E2A-PBX1 cKI mice. Inverse PCR identified eight retroviral common integration sites, in which enhanced expression was observed in the Gfi1, Mycn, and Pim1 genes. In addition, it is of note that viral integration and overexpression of the Zfp521 gene was detected in one tumor with B-cell lineage; we previously identified Zfp521 as a cooperative gene with E2A-HLF, another E2A-involving fusion gene with B-lineage ALL. The cooperative oncogenicity of E2A-PBX1 with overexpressed Zfp521 in B-cell tumorigenesis was indicated by the finding that E2A-PBX1 cKI, Zfp521 transgenic compound mice developed B-lineage ALL. Moreover, upregulation of ZNF521, the human counterpart of Zfp521, was found in several human leukemic cell lines bearing t(1;19). These results indicate that E2A-PBX1 cooperates with additional gene alterations to develop ALL. Among them, enhanced expression of ZNF521 may play a clinically relevant role in E2A fusion genes to develop B-lineage ALL.

Fbxl10 overexpression in murine hematopoietic stem cells induces leukemia involving metabolic activation and upregulation of Nsg2.

We previously reported that deficiency for Samd9L, which was cloned as a candidate gene for -7/7q- syndrome, accelerated leukemia cooperatively with enhanced expression of a histone demethylase: F-box and leucine-rich repeat protein 10 (Fbxl10, also known as Jhdm1b, Kdm2b, and Ndy1). To further investigate the role of Fbxl10 in leukemogenesis, we generated transgenic (Tg) mice that overexpress Fbxl10 in hematopoietic stem cells (HSCs). Interestingly, Fbxl10 Tg mice developed myeloid or B-lymphoid leukemia with complete penetrance. HSCs from the Tg mice exhibited an accelerated G0/G1-to-S transition with a normal G0 to G1 entry, resulting in pleiotropic progenitor cell expansion. Fbxl10 Tg HSCs displayed enhanced expression of neuron-specific gene family member 2 (Nsg2), and forced expression of Nsg2 in primary bone marrow cells resulted in expansion of immature cells. In addition, the genes involved in mitochondrial oxidative phosphorylation were markedly enriched in Fbxl10 Tg HSCs, coupled with increased cellular adenosine 5'-triphosphate levels. Moreover, chromatin immunoprecipitation followed by sequencing analysis demonstrated that Fbxl10 directly binds to the regulatory regions of Nsg2 and oxidative phosphorylation genes. These findings define Fbxl10 as a bona fide oncogene, whose deregulated expression contributes to the development of leukemia involving metabolic proliferative advantage and Nsg2-mediated impaired differentiation.