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Tu J, Chen W, Fang Y, Han D, Chen Y, Jiang H, Tan X, Xu Z, Wu X, Wang H, Zhu X, Hong W, Li Z, Zhu C, Wang X, Wei W. PU.1 promotes development of rheumatoid arthritis via repressing FLT3 in macrophages and fibroblast-like synoviocytes. Ann Rheum Dis 2023; 82:198-211. [PMID: 36198439 PMCID: PMC9887374 DOI: 10.1136/ard-2022-222708] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 09/13/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVES To uncover the function and underlying mechanism of an essential transcriptional factor, PU.1, in the development of rheumatoid arthritis (RA). METHODS The expression and localisation of PU.1 and its potential target, FMS-like tyrosine kinase 3 (FLT3), in the synovium of patients with RA were determined by western blot and immunohistochemical (IHC) staining. UREΔ (with PU.1 knockdown) and FLT3-ITD (with FLT3 activation) mice were used to establish collagen antibody-induced arthritis (CAIA). For the in vitro study, the effects of PU.1 and FLT3 on primary macrophages and fibroblast-like synoviocytes (FLS) were investigated using siRNAs. Mechanistically, luciferase reporter assays, western blotting, FACS and IHC were conducted to show the direct regulation of PU.1 on the transcription of FLT3 in macrophages and FLS. Finally, a small molecular inhibitor of PU.1, DB2313, was used to further illustrate the therapeutic effects of DB2313 on arthritis using two in vivo models, CAIA and collagen-induced arthritis (CIA). RESULTS The expression of PU.1 was induced in the synovium of patients with RA when compared with that in osteoarthritis patients and normal controls. FLT3 and p-FLT3 showed opposite expression patterns compared with PU.1 in RA. The CAIA model showed that PU.1 was an activator, whereas FLT3 was a repressor, of the development of arthritis in vivo. Moreover, results from in vitro assays were consistent with the in vivo results: PU.1 promoted hyperactivation and inflammatory status of macrophages and FLS, whereas FLT3 had the opposite effects. In addition, PU.1 inhibited the transcription of FLT3 by directly binding to its promoter region. The PU.1 inhibitor DB2313 clearly alleviated the effects on arthritis development in the CAIA and CIA models. CONCLUSIONS These results support the role of PU.1 in RA and may have therapeutic implications by directly repressing FLT3. Therefore, targeting PU.1 might be a potential therapeutic approach for RA.
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Affiliation(s)
- Jiajie Tu
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Weile Chen
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Yilong Fang
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Dafei Han
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Yizhao Chen
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Haifeng Jiang
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Xuewen Tan
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Zhen Xu
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Xuming Wu
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Huihui Wang
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Xiangling Zhu
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Wenming Hong
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Zhenbao Li
- College of Pharmacy, Anhui University of Traditional Chinese Medicine, Hefei, Anhui, China
| | - Chen Zhu
- Department of Orthopedics, University of Science and Technology of China, Hefei, Anhui, China
| | - Xinming Wang
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
| | - Wei Wei
- Institute of Clinical Pharmacology, Anhui Medical University, Hefei, China
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Dziegiel P, Pula B, Kobierzycki C, Stasiolek M, Podhorska-Okolow M. The Role of Metallothioneins in Carcinogenesis. ADVANCES IN ANATOMY EMBRYOLOGY AND CELL BIOLOGY 2016. [DOI: 10.1007/978-3-319-27472-0_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Wang J, Li T, Zhou M, Hu Z, Zhou X, Zhou S, Wang N, Huang L, Zhao L, Cao Y, Xiao M, Ma D, Zhou P, Shang Z, Zhou J. TALENs-mediated gene disruption of FLT3 in leukemia cells: Using genome-editing approach for exploring the molecular basis of gene abnormality. Sci Rep 2015; 5:18454. [PMID: 26669855 PMCID: PMC4680874 DOI: 10.1038/srep18454] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 11/17/2015] [Indexed: 12/11/2022] Open
Abstract
Novel analytic tools are needed to elucidate the molecular basis of leukemia-relevant gene mutations in the post-genome era. We generated isogenic leukemia cell clones in which the FLT3 gene was disrupted in a single allele using TALENs. Isogenic clones with mono-allelic disrupted FLT3 were compared to an isogenic wild-type control clone and parental leukemia cells for transcriptional expression, downstream FLT3 signaling and proliferation capacity. The global gene expression profiles of mutant K562 clones and corresponding wild-type controls were compared using RNA-seq. The transcriptional levels and the ligand-dependent autophosphorylation of FLT3 were decreased in the mutant clones. TALENs-mediated FLT3 haplo-insufficiency impaired cell proliferation and colony formation in vitro. These inhibitory effects were maintained in vivo, improving the survival of NOD/SCID mice transplanted with mutant K562 clones. Cluster analysis revealed that the gene expression pattern of isogenic clones was determined by the FLT3 mutant status rather than the deviation among individual isogenic clones. Differentially expressed genes between the mutant and wild-type clones revealed an activation of nonsense-mediated decay pathway in mutant K562 clones as well as an inhibited FLT3 signaling. Our data support that this genome-editing approach is a robust and generally applicable platform to explore the molecular bases of gene mutations.
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Affiliation(s)
- Jue Wang
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Tongjuan Li
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Mi Zhou
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zheng Hu
- Cancer Biology Research Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xiaoxi Zhou
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Shiqiu Zhou
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Na Wang
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Liang Huang
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lei Zhao
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yang Cao
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Min Xiao
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ding Ma
- Cancer Biology Research Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Pengfei Zhou
- Wuhan YZY Bio-Pharma Co., Ltd., Wuhan, Hubei, China
| | - Zhen Shang
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jianfeng Zhou
- Department of hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.,Cancer Biology Research Center, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
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A PU.1 suppressive target gene, metallothionein 1G, inhibits retinoic acid-induced NB4 cell differentiation. PLoS One 2014; 9:e103282. [PMID: 25072246 PMCID: PMC4114787 DOI: 10.1371/journal.pone.0103282] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 06/30/2014] [Indexed: 11/19/2022] Open
Abstract
We recently revealed that myeloid master regulator SPI1/PU.1 directly represses metallothionein (MT) 1G through its epigenetic activity of PU.1, but the functions of MT1G in myeloid differentiation remain unknown. To clarify this, we established MT1G-overexpressing acute promyelocytic leukemia NB4 (NB4MTOE) cells, and investigated whether MT1G functionally contributes to all-trans retinoic acid (ATRA)-induced NB4 cell differentiation. Real-time PCR analyses demonstrated that the inductions of CD11b and CD11c and reductions in myeloperoxidase and c-myc by ATRA were significantly attenuated in NB4MTOE cells. Morphological examination revealed that the percentages of differentiated cells induced by ATRA were reduced in NB4MTOE cells. Since G1 arrest is a hallmark of ATRA-induced NB4 cell differentiation, we observed a decrease in G1 accumulation, as well as decreases in p21WAF1/CIP1 and cyclin D1 inductions, by ATRA in NB4MTOE cells. Nitroblue tetrazolium (NBT) reduction assays revealed that the proportions of NBT-positive cells were decreased in NB4MTOE cells in the presence of ATRA. Microarray analyses showed that the changes in expression of several myeloid differentiation-related genes (GATA2, azurocidin 1, pyrroline-5-carboxylate reductase 1, matrix metallopeptidase -8, S100 calcium-binding protein A12, neutrophil cytosolic factor 2 and oncostatin M) induced by ATRA were disturbed in NB4MTOE cells. Collectively, overexpression of MT1G inhibits the proper differentiation of myeloid cells.
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Olme CH, Finnon R, Brown N, Kabacik S, Bouffler S, Badie C. Live cell detection of chromosome 2 deletion and Sfpi1/PU1 loss in radiation-induced mouse acute myeloid leukaemia. Leuk Res 2013; 37:1374-82. [PMID: 23806234 PMCID: PMC3775122 DOI: 10.1016/j.leukres.2013.05.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/24/2013] [Accepted: 05/26/2013] [Indexed: 12/20/2022]
Abstract
The CBA/H mouse model of radiation-induced acute myeloid leukaemia (rAML) has been studied for decades to bring to light the molecular mechanisms associated with multistage carcinogenesis. A specific interstitial deletion of chromosome 2 found in a high proportion of rAML is recognised as the initiating event. The deletion leads to the loss of Sfpi, a gene essential for haematopoietic development. Its product, the transcription factor PU.1 acts as a tumour suppressor in this model. Although the deletion can be detected early following ionising radiation exposure by cytogenetic techniques, precise characterisation of the haematopoietic cells carrying the deletion and the study of their fate in vivo cannot be achieved. Here, using a genetically engineered C57BL/6 mouse model expressing the GFP fluorescent molecule under the control of the Sfpi1 promoter, which we have bred onto the rAML-susceptible CBA/H strain, we demonstrate that GFP expression did not interfere with X-ray induced leukaemia incidence and that GFP fluorescence in live leukaemic cells is a surrogate marker of radiation-induced chromosome 2 deletions with or without point mutations on the remaining allele of the Sfpi1 gene. This study presents the first experimental evidence for the detection of this leukaemia initiating event in live leukemic cells.
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MESH Headings
- Animals
- Bone Marrow Cells/metabolism
- Bone Marrow Cells/pathology
- Chromosome Deletion
- Disease Models, Animal
- Exons
- Female
- Flow Cytometry
- Gene Deletion
- Gene Expression
- Genes, Reporter
- Genetic Predisposition to Disease
- Immunophenotyping
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/mortality
- Leukemia, Radiation-Induced/genetics
- Leukemia, Radiation-Induced/metabolism
- Mice
- Mutation
- Proto-Oncogene Proteins/genetics
- Trans-Activators/genetics
- Transcription, Genetic
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Affiliation(s)
| | | | | | | | | | - C. Badie
- Biological Effects Department, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, Oxfordshire, UK
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Alachkar H, Santhanam R, Harb JG, Lucas DM, Oaks JJ, Hickey CJ, Pan L, Kinghorn AD, Caligiuri MA, Perrotti D, Byrd JC, Garzon R, Grever MR, Marcucci G. Silvestrol exhibits significant in vivo and in vitro antileukemic activities and inhibits FLT3 and miR-155 expressions in acute myeloid leukemia. J Hematol Oncol 2013; 6:21. [PMID: 23497456 PMCID: PMC3623627 DOI: 10.1186/1756-8722-6-21] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 02/14/2013] [Indexed: 01/02/2023] Open
Abstract
Background Activating mutations [internal tandem duplication (ITD)] or overexpression of the FMS-like tyrosine kinase receptor-3 (FLT3) gene are associated with poor outcome in acute myeloid leukemia (AML) patients, underscoring the need for novel therapeutic approaches. The natural product silvestrol has potent antitumor activity in several malignancies, but its therapeutic impact on distinct molecular high-risk AML subsets remains to be fully investigated. We examined here the preclinical activity of silvestrol in FLT3-ITD and FLT3 wild-type (wt) AML. Methods Silvestrol in vitro anti-leukemic activity was examined by colorimetric cell viability assay, colony-forming and flow cytometry assays assessing growth inhibition and apoptosis, respectively. Pharmacological activity of silvestrol on FLT3 mRNA translation, mRNA and protein expression was determined by RNA-immunoprecipitation, qRT-PCR and immunoblot analyses, respectively. Silvestrol in vivo efficacy was investigated using MV4-11 leukemia-engrafted mice. Results Silvestrol shows antileukemia activity at nanomolar concentrations both in FLT3-wt overexpressing (THP-1) and FLT3-ITD (MV4-11) expressing AML cell lines (IC50 = 3.8 and 2.7 nM, respectively) and patients’ primary blasts [IC50 = ~12 nM (FLT3-wt) and ~5 nM (FLT3-ITD)]. Silvestrol increased apoptosis (~4fold, P = 0.0001), and inhibited colony-formation (100%, P < 0.0001) in primary blasts. Silvestrol efficiently inhibited FLT3 translation reducing FLT3 protein expression by 80–90% and decreased miR-155 levels (~60%), a frequently co-regulated onco-miR in FLT3-ITD-positive AML. The median survival of silvestrol-treated vs vehicle-treated mice was 63 vs 29 days post-engraftment, respectively (P < 0.0001). Conclusions Silvestrol exhibits significant in vivo and in vitro antileukemic activities in AML through a novel mechanism resulting in inhibition of FLT3 and miR-155 expression. These encouraging results warrant a rapid translation of silvestrol for clinical testing in AML.
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Affiliation(s)
- Houda Alachkar
- Division of Hematology, Department of Medicine, The Ohio State University, Columbus, OH, USA.
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Suzuki S, Nakano H, Takahashi S. Epigenetic regulation of the metallothionein-1A promoter by PU.1 during differentiation of THP-1 cells. Biochem Biophys Res Commun 2013; 433:349-53. [PMID: 23501100 DOI: 10.1016/j.bbrc.2013.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 03/06/2013] [Indexed: 01/30/2023]
Abstract
We recently demonstrated that metallothionein (MT)-1 A is a direct target gene negatively regulated by PU.1. In this study, we revealed that the expression of PU.1 was increased and accompanied by downregulation of MT-1A expression during TPA-induced THP-1 monocyte differentiation. Chromatin immunoprecipitation (ChIP) analysis demonstrated that PU.1 and the methyl CpG binding protein (MeCP) 2 bound to the same -887 to -602 region in the MT-1A promoter, and the binding of these proteins to this promoter was enhanced during differentiation. Consistently, bisulfite sequencing analyses around this region revealed that the proportion of methylated CpG sites was obivously increased during differentiation. In addition, ChIP analysis demonstrated that acetylated histone H4 around this region tended to be reduced and this may also play a role in the reduction of MT-1A expression during differentiation. Taken together, these findings suggest that MT-1A is epigenetically regulated by PU.1 during monocytic differentiation.
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Affiliation(s)
- Sawami Suzuki
- Division of Molecular Hematology, Kitasato University Graduate School of Medical Sciences, Miniami-ku, Sagamihara, Kanagawa, Japan
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8
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Takahashi S. Molecular functions of metallothionein and its role in hematological malignancies. J Hematol Oncol 2012; 5:41. [PMID: 22839501 PMCID: PMC3419633 DOI: 10.1186/1756-8722-5-41] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Accepted: 07/27/2012] [Indexed: 11/10/2022] Open
Abstract
Metallothionein (MT) was reported to be a potential negative regulator of apoptosis, and various reports have suggested that it may play roles in carcinogenesis and drug resistance, in at least a portion of cancer cells. The author summarizes the current understanding of the molecular functions of MT for tumor cell growth and drug resistance. These activities are regulated through intracellular metal ion modulation and free radical scavenging. Compared with analyses of solid tumors, few studies have analyzed the roles of MT in hematological malignancies. This review mainly describes the functions of MT in hematopoietic cells. Furthermore, through expression analyses of leukemias and lymphomas, the roles of MT in the biology of these diseases are particularly focused upon.
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Affiliation(s)
- Shinichiro Takahashi
- Division of Hematology, Kitasato University School of Allied Health Sciences, 1-15-1 Kitasato, Minami-ku, Sagamihara, 252-0373, Japan.
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Takahashi S. Downstream molecular pathways of FLT3 in the pathogenesis of acute myeloid leukemia: biology and therapeutic implications. J Hematol Oncol 2011; 4:13. [PMID: 21453545 PMCID: PMC3076284 DOI: 10.1186/1756-8722-4-13] [Citation(s) in RCA: 150] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 04/01/2011] [Indexed: 01/13/2023] Open
Abstract
FLT3 is a type III receptor tyrosine kinase. Mutations of FLT3 comprise one of the most frequently identified types of genetic alterations in acute myeloid leukemia. One-third of acute myeloid leukemia patients have mutations of this gene, and the majority of these mutations involve an internal tandem duplication in the juxtamembrane region of FLT3, leading to constitutive activation of downstream signaling pathways and aberrant cell growth. This review summarizes the current understanding of the effects of the downstream molecular signaling pathways after FLT3 activation, with a particular focus on the effects on transcription factors. Moreover, this review describes novel FLT3-targeted therapies, as well as efficient combination therapies for FLT3-mutated leukemia cells.
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Affiliation(s)
- Shinichiro Takahashi
- The Division of Molecular Hematology, Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Minami-ku, Sagamihara 252-0373, Japan.
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Sfpi1/PU.1 mutations in mouse radiation-induced acute myeloid leukaemias affect mRNA and protein abundance and associate with disrupted transcription. Leuk Res 2010; 35:126-32. [PMID: 20638124 DOI: 10.1016/j.leukres.2010.06.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 06/12/2010] [Accepted: 06/16/2010] [Indexed: 11/22/2022]
Abstract
Radiation-induced acute myeloid leukaemias (AMLs) in mice are characterised by deletions and point mutations in the Sfpi1/PU.1 transcription factor. Six AML cell lines were used to examine the impact of three previously described R235 point mutations. AML cells carry myeloid and stem cell markers and the R235 mutations differentially affect mRNA and protein abundance. Expression of Sfpi1/PU.1 target genes was deregulated in a broadly similar fashion irrespective of R235 mutation including Flt3, which is frequently subject to activating mutations in human myeloid leukaemias. While R235 mutations differentially affect protein abundance they resulted in similar disruption of Sfpi1/PU.1 functions.
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11
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Imoto A, Okada M, Okazaki T, Kitasato H, Harigae H, Takahashi S. Metallothionein-1 isoforms and vimentin are direct PU.1 downstream target genes in leukemia cells. J Biol Chem 2010; 285:10300-9. [PMID: 20139074 DOI: 10.1074/jbc.m109.095810] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PU.1 is a key transcription factor for hematopoiesis and plays important roles in various hematological malignancies. To clarify the molecular function of PU.1, we initially tried to identify bona fide target genes regulated by PU.1. Dual microarrays were employed for this study to compare PU.1-knockdown K562 cells (K562PU.1KD) stably expressing PU.1 short inhibitory RNAs versus control cells and PU.1-overexpressing K562 cells (K562PU.1OE) versus control cells. In these analyses, we found that several genes, including metallothionein (MT)-1 isoforms (MT-1G and MT-1A) and vimentin (VIM), were markedly induced while Jun dimerization protein (JDP) 2 was suppressed in K562PU.1KD cells. Furthermore, the mRNA expressions of the MT-1 and VIM genes were inversely correlated and the mRNA expression of JDP2 was positively correlated with PU.1 mRNA expression in 43 primary acute myeloid leukemia specimens (MT-1G: R = -0.50, p < 0.001; MT-1A: R = -0.58, p < 0.0005; VIM: R = -0.39, p < 0.01; and JDP2: R = 0.30, p < 0.05). Next, we analyzed the regulation of the MT-1 and VIM genes. We observed increased associations of acetylated histones H3 and H4 with the promoters of these genes in K562PU.1KD cells. Sequence analyses of the regions approximately 1 kb upstream from the transcription start sites of these genes revealed numerous CpG sites, which are potential targets for DNA methylation. Chromatin immunoprecipitation assays revealed that methyl CpG-binding protein 2 (MeCP2) and PU.1 bound to the CpG-rich regions in the MT-1 and VIM promoters. Bisulfite sequencing analyses of the PU.1-bound regions of these promoters revealed that the proportions of methylated CpG sites were tightly related to the PU.1 expression levels.
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Affiliation(s)
- Akemi Imoto
- Division of Molecular Hematology, Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Minamiku, Sagamihara 252-0373, Japan
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Iseki Y, Imoto A, Okazaki T, Harigae H, Takahashi S. Identification of annexin 1 as a PU.1 target gene in leukemia cells. Leuk Res 2009; 33:1658-63. [PMID: 19428102 DOI: 10.1016/j.leukres.2009.04.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 03/12/2009] [Accepted: 04/07/2009] [Indexed: 11/25/2022]
Abstract
To identify PU.1 downstream target genes, we first established PU.1-knockdown K562 (K562PU.1KD) cells expressing reduced levels of PU.1 by stably transfected PU.1 siRNAs. From microarray analysis, we found that several genes including annexin 1 were markedly induced in K562PU.1KD cells. Annexin 1 is a calcium- and phospholipid-binding protein and increased expression leads to the constitutive activation of extracellular signal-regulated kinase (ERK). Consistent with this, we observed constitutive activation of ERK in K562PU.1KD cells. Furthermore, we revealed the mRNA expression of annexin 1 was negatively correlated with PU.1 mRNA expression in 43 primary AML specimens (R=-0.31, p<0.042).
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Affiliation(s)
- Yuko Iseki
- Division of Molecular Hematology, Kitasato University Graduate School of Medical Sciences, 1-15-1 Kitasato, Sagamihara City, Kanagawa 228-8555, Japan
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13
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Na G, Bridges PJ, Koo Y, Ko C. Role of hypoxia in the regulation of periovulatory EDN2 expression in the mouse. Can J Physiol Pharmacol 2008; 86:310-9. [PMID: 18516093 DOI: 10.1139/y08-025] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have previously proposed endothelin-2 (EDN2) as a granulosa cell-derived contractile signal that facilitates ovulation. Spatially, Edn2 mRNA expression is restricted to granulosa cells of periovulatory follicles. Temporally, mRNA for this contractile peptide is expressed immediately before follicle rupture. The primary objective of this study was to test the hypothesis that hypoxia mediates EDN2 expression in granulosa cells at ovulation, and if it does, to determine the region within the promoter responsible for this effect. To determine the effect of hypoxia on mRNA expression, immature mice were treated with 5 IU of PMSG followed 48 h later by 5 IU of human chorionic gonadotropin (hCG). Granulosa cells were isolated at 9 h after hCG, cultured under normal or hypoxic conditions, and the expression level of mRNA was compared. mRNA expression was increased when granulosa cells were cultured in a hypoxic environment (p<0.05). Subsequent promoter analysis found that the 5' upstream region of the EDN2 promoter (between -1894 bp and -1407 bp) was responsible for hypoxia-mediated changes in EDN2 expression. This promoter region contains multiple sites for potential transcriptional regulation, including that by hypoxia-inducible factor 1 (HIF-1, ACGTG) at -1297 bp. The second objective of this study was to determine whether the progesterone receptor (PR) or cyclooxygenase-2 (COX-2), two key regulators of periovulatory events, controlled EDN2 expression. To accomplish this, gonadotropin-primed mice were treated with RU-486 or indomethacin and expression of mRNA for Edn2 was determined in ovaries collected at 12 h after hCG. Treatment with RU-486 or indomethacin did not affect expression of mRNA for Edn2 (p>0.05). Taken together, we believe that hypoxia, but not the PR or COX-2, regulate gonadotropin-induced EDN2 expression in the periovulatory follicle.
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Affiliation(s)
- Giyoun Na
- Division of Clinical and Reproductive Sciences, University of Kentucky, Lexington, KY 40536, USA
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Mankaï A, Bordron A, Renaudineau Y, Martins-Carvalho C, Takahashi S, Ghedira I, Berthou C, Youinou P. Purine-Rich Box-1–Mediated Reduced Expression of CD20 Alters Rituximab-Induced Lysis of Chronic Lymphocytic Leukemia B Cells. Cancer Res 2008; 68:7512-9. [DOI: 10.1158/0008-5472.can-07-6446] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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D’Alò F, Di Ruscio A, Guidi F, Fabiani E, Greco M, Rumi C, Hohaus S, Voso MT, Leone G. PU.1 and CEBPA expression in acute myeloid leukemia. Leuk Res 2008; 32:1448-53. [DOI: 10.1016/j.leukres.2008.01.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2007] [Revised: 12/03/2007] [Accepted: 01/14/2008] [Indexed: 10/22/2022]
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Takahashi S, Harigae H, Yokoyama H, Ishikawa I, Abe S, Imaizumi M, Sasaki T, Kaku M. Synergistic effect of arsenic trioxide and flt3 inhibition on cells with flt3 internal tandem duplication. Int J Hematol 2006; 84:256-61. [PMID: 17050201 DOI: 10.1532/ijh97.06076] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Flt3 internal tandem duplication (Flt3-ITD) is a prevalent mutation in acute myeloid leukemia (AML). Flt3-ITD constitutively activates various signaling pathways, including a mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway. Arsenic trioxide (ATO) and MEK inhibition were recently reported to interact synergistically to induce apoptosis in AML cells. In this study, we aimed to clarify whether ATO and Flt3 inhibition would be a more specific and efficient therapy for Flt3-ITD cells. We demonstrate that the combination of ATO and an Flt3 inhibitor, AG1296, profoundly inhibits the growth of Flt3-ITD cells and induces their apoptosis. We further revealed that this combined treatment potently inhibits the ERK activity that might be responsible for cell growth. Moreover, using the Chou-Talalay method, we observed a synergistic growth-inhibitory effect for ATO and AG1296 in Flt3-ITD cells (BaF3-Flt3-ITD, MV4-11, and PL-21 cells), but not in Flt3 wild-type cells (RS4-11 and NB4 cells), for almost all dose ranges tested. Our results provide an experimental basis for a specific and efficient therapy for Flt3-ITD cells that involves combined treatment with Flt3 inhibitors and ATO.
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Affiliation(s)
- Shinichiro Takahashi
- Department of Infection Control and Laboratory Diagnostics, Tohoku University Graduate School of Medicine, Sendai, Japan.
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