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Silconi ZB, Rosic V, Benazic S, Radosavljevic G, Mijajlovic M, Pantic J, Ratkovic ZR, Radic G, Arsenijevic A, Milovanovic M, Arsenijevic N, Milovanovic J. The Pt(S-pr-thiosal)2 and BCL1 Leukemia Lymphoma: Antitumor Activity In Vitro and In Vivo. Int J Mol Sci 2022; 23:ijms23158161. [PMID: 35897737 PMCID: PMC9332548 DOI: 10.3390/ijms23158161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/16/2022] Open
Abstract
B cell malignancies are, despite the development of targeted therapy in a certain percentage of the patients still a chronic disease with relapses, requiring multiple lines of therapy. Regimens that include platinum-based drugs provide high response rates in different B cell lymphomas, high-risk chronic lymphocytic leukemia (CLL), and devastating complication of CLL, Richter’s syndrome. The aim of this study was to explore the potential antitumor activity of previously synthetized platinum(IV) complex with alkyl derivatives of thyosalicilc acid, PtCl2(S-pr-thiosal)2, toward murine BCL1 cells and to delineate possible mechanisms of action. The PtCl2(S-pr-thiosal)2 reduced the viability of BCL1 cells in vitro but also reduced the growth of metastases in the leukemia lymphoma model in BALB/c mice. PtCl2(S-pr-thiosal)2 induced apoptosis, inhibited proliferation of BCL1 cells, and induced cell cycle disturbance. Treatment of BCL1 cells with PtCl2(S-pr-thiosal)2 inhibited expression of cyclin D3 and cyclin E and enhanced expression of cyclin-dependent kinase inhibitors p16, p21, and p27 resulting in cell cycle arrest in the G1 phase, reduced the percentage of BCL1 cells in the S phase, and decreased expression of Ki-67. PtCl2(S-pr-thiosal)2 treatment reduced expression of phosphorylated STAT3 and downstream-regulated molecules associated with cancer stemness and proliferation, NANOG, cyclin D3, and c-Myc, and expression of phosphorylated NFκB in vitro and in vivo. In conclusion, PtCl2(S-pr-thiosal)2 reduces STAT3 and NFκB phosphorylation resulting in inhibition of BCL1 cell proliferation and the triggering of apoptotic cell death.
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Affiliation(s)
| | - Vesna Rosic
- Department of Histology and Embryology, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia;
| | - Sasa Benazic
- Department of Transfusiology, Pula General Hospital, 52100 Pula, Croatia;
| | - Gordana Radosavljevic
- Center for Molecular Medicine & Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia; (G.R.); (J.P.); (A.A.); (M.M.); (N.A.)
| | - Marina Mijajlovic
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia; (M.M.); (G.R.)
| | - Jelena Pantic
- Center for Molecular Medicine & Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia; (G.R.); (J.P.); (A.A.); (M.M.); (N.A.)
| | - Zoran R. Ratkovic
- Department of Chemistry, Faculty of Science, University of Kragujevac, 34000 Kragujevac, Serbia;
| | - Gordana Radic
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia; (M.M.); (G.R.)
| | - Aleksandar Arsenijevic
- Center for Molecular Medicine & Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia; (G.R.); (J.P.); (A.A.); (M.M.); (N.A.)
| | - Marija Milovanovic
- Center for Molecular Medicine & Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia; (G.R.); (J.P.); (A.A.); (M.M.); (N.A.)
| | - Nebojsa Arsenijevic
- Center for Molecular Medicine & Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia; (G.R.); (J.P.); (A.A.); (M.M.); (N.A.)
| | - Jelena Milovanovic
- Department of Histology and Embryology, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia;
- Center for Molecular Medicine & Stem Cell Research, Faculty of Medical Sciences, University of Kragujevac, 34000 Kragujevac, Serbia; (G.R.); (J.P.); (A.A.); (M.M.); (N.A.)
- Correspondence: ; Tel.: +381-3430-6800
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Morris R, Kershaw NJ, Babon JJ. The molecular details of cytokine signaling via the JAK/STAT pathway. Protein Sci 2019; 27:1984-2009. [PMID: 30267440 DOI: 10.1002/pro.3519] [Citation(s) in RCA: 432] [Impact Index Per Article: 86.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/24/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022]
Abstract
More than 50 cytokines signal via the JAK/STAT pathway to orchestrate hematopoiesis, induce inflammation and control the immune response. Cytokines are secreted glycoproteins that act as intercellular messengers, inducing proliferation, differentiation, growth, or apoptosis of their target cells. They act by binding to specific receptors on the surface of target cells and switching on a phosphotyrosine-based intracellular signaling cascade initiated by kinases then propagated and effected by SH2 domain-containing transcription factors. As cytokine signaling is proliferative and often inflammatory, it is tightly regulated in terms of both amplitude and duration. Here we review molecular details of the cytokine-induced signaling cascade and describe the architectures of the proteins involved, including the receptors, kinases, and transcription factors that initiate and propagate signaling and the regulatory proteins that control it.
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Affiliation(s)
- Rhiannon Morris
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3050, Victoria, Australia
| | - Nadia J Kershaw
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3050, Victoria, Australia
| | - Jeffrey J Babon
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3050, Victoria, Australia
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Mesbahi Y, Zekri A, Ghaffari SH, Tabatabaie PS, Ahmadian S, Ghavamzadeh A. Blockade of JAK2/STAT3 intensifies the anti-tumor activity of arsenic trioxide in acute myeloid leukemia cells: Novel synergistic mechanism via the mediation of reactive oxygen species. Eur J Pharmacol 2018; 834:65-76. [PMID: 30012499 DOI: 10.1016/j.ejphar.2018.07.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 07/02/2018] [Accepted: 07/12/2018] [Indexed: 12/12/2022]
Abstract
Reactive oxygen species (ROS) are essential mediators of crucial cellular processes including apoptosis, proliferation, survival and cell cycle. Their regulatory role in cancer progression has seen in different human malignancies such as acute myeloid leukemia (AML). AML patients suffer from high resistance of the tumors against routine therapeutics including ATO. ATO enhance reactive oxygen species levels and induce apoptosis and suppresses proliferation in AML cells. However, some pathways such as JAK2/STAT3 ease anti-tumor activity of ATO by reducing reactive oxygen species amount and protecting the cell from apoptosis. In the present study, we use ruxolitinib (potent JAK2 inhibitor) to increase the sensitivity of AML cells to ATO treatment. We test, the effect of this combination on metabolic activity, proliferation, colony formation, cell cycle distribution, apoptosis, oxidative stress and DNA damage. Our results showed that combination of ATO with ruxolitinib synergistically reduced metabolic activity, proliferation and survival of AML cell lines. This combination induced G1/S cell cycle arrest because of reactive oxygen species elevation and GSH reduction. Besides, enhancement of reactive oxygen species increased apoptosis rate in combination samples. We uncovered that the synergistic anti-tumor effect of ATO and ruxolitinib in AML cells mediates via reactive oxygen species elevation and DNA damage. Overall, our results show that the combinatorial therapy of AML cells is more effective than solo-targeted therapy.
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Affiliation(s)
- Yashar Mesbahi
- Hematologic Malignancies Research Center, Tehran University of Medical Sciences, Tehran, Iran; Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, Iran
| | - Ali Zekri
- Physiology Research Center, Faculty of Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran; Department of Medical Genetics and Molecular Biology, Faculty of Medicine, Iran University of Medical Sciences (IUMS), Tehran, Iran
| | - Seyed H Ghaffari
- Hematologic Malignancies Research Center, Tehran University of Medical Sciences, Tehran, Iran; Hematology, Oncology and Stem Cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran; Cell Therapy and Hematopoietic Stem Cell Transplantation Research Center, Tehran, Iran.
| | | | - Shahin Ahmadian
- Institute of Biochemistry and Biophysics, University of Tehran, P.O. Box 13145-1384, Tehran, Iran
| | - Ardeshir Ghavamzadeh
- Hematologic Malignancies Research Center, Tehran University of Medical Sciences, Tehran, Iran; Hematology, Oncology and Stem Cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran; Cell Therapy and Hematopoietic Stem Cell Transplantation Research Center, Tehran, Iran
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Bowman T, Yu H, Sebti S, Dalton W, Jove R. Signal Transducers and Activators of Transcription: Novel Targets for Anticancer Therapeutics. Cancer Control 2017. [DOI: 10.1177/107327489900600501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Background Through specific activation of gene expression, the family of proteins known as signal transducers and activators of transcription (STATs) converts extracellular stimuli into diverse biological responses. Beyond the normal signaling functions of STATs, recent evidence indicates that aberrant activation of STATs contributes to neoplastic transformation. Methods Current literature pertaining to the role of STAT proteins in oncogenesis is presented. Also, the rationale for developing novel approaches to disrupt STAT signaling is discussed, and the potential of STATs as anticancer targets in treating human cancer is reviewed. Results The discovery that certain oncoproteins constitutively activate specific STATs, coupled with observations that elevated STAT activity occurs frequently in a spectrum of human tumors, establishes a direct link between STAT activation and neoplastic transformation. Significantly, abrogation of STAT signaling blocks oncogenesis in model in vitro and in vivo systems. These results make STATs attractive targets for rational design of small molecule inhibitors and gene therapy approaches to disrupt STAT signaling. Conclusions As a result of genetic, biochemical, and crystallographic analyses, the functional domains of STAT proteins have been well characterized. Based on these data, selective inhibitors of STAT function can be designed. Because disrupting STAT signaling has proven effective in blocking neoplastic transformation, it is proposed that STAT proteins represent promising targets for development of novel molecular therapeutics to treat human cancer.
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Affiliation(s)
- Tammy Bowman
- Molecular Oncology Program at the H. Lee Moffitt Cancer Center & Research Institute, Tampa, Fla
| | - Hua Yu
- Immunology Program at the H. Lee Moffitt Cancer Center & Research Institute, Tampa, Fla
| | - Saïd Sebti
- Drug Discovery Program at the H. Lee Moffitt Cancer Center & Research Institute, Tampa, Fla
| | - William Dalton
- Clinical Investigations Program at the H. Lee Moffitt Cancer Center & Research Institute, Tampa, Fla
| | - Richard Jove
- Molecular Oncology Program at the H. Lee Moffitt Cancer Center & Research Institute, Tampa, Fla
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Abstract
Kinase pathways are primary effectors of many targeted therapy approaches for cancer. Kinase pathways can be dysregulated by mechanisms far more diverse than chromosomal rearrangements or point mutations, which drove the initial application of kinase inhibitors to cancer. Functional screening with kinase inhibitors is one tool by which we can understand the diversity of target kinases and candidate drugs for patients before fully understanding the mechanistic rationale for kinase pathway dysregulation. By combining functional screening with genomic data, it is also possible to accelerate understanding of these mechanistic underpinnings.
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Affiliation(s)
- Jeffrey W Tyner
- Department of Cell, Developmental and Cancer Biology, Knight Cancer Institute, Oregon Health and Science University, OHSU BRB 511, Mailcode L592, 3181 Southwest Sam Jackson Park Road, Portland, OR 97239, USA.
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Murone M, Radpour R, Attinger A, Chessex AV, Huguenin AL, Schürch CM, Banz Y, Sengupta S, Aguet M, Rigotti S, Bachhav Y, Massière F, Ramachandra M, McAllister A, Riether C. The Multi-kinase Inhibitor Debio 0617B Reduces Maintenance and Self-renewal of Primary Human AML CD34 + Stem/Progenitor Cells. Mol Cancer Ther 2017; 16:1497-1510. [PMID: 28468777 DOI: 10.1158/1535-7163.mct-16-0889] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 03/16/2017] [Accepted: 04/20/2017] [Indexed: 01/05/2023]
Abstract
Acute myelogenous leukemia (AML) is initiated and maintained by leukemia stem cells (LSC). LSCs are therapy-resistant, cause relapse, and represent a major obstacle for the cure of AML. Resistance to therapy is often mediated by aberrant tyrosine kinase (TK) activation. These TKs primarily activate downstream signaling via STAT3/STAT5. In this study, we analyzed the potential to therapeutically target aberrant TK signaling and to eliminate LSCs via the multi-TK inhibitor Debio 0617B. Debio 0617B has a unique profile targeting key kinases upstream of STAT3/STAT5 signaling such as JAK, SRC, ABL, and class III/V receptor TKs. We demonstrate that expression of phospho-STAT3 (pSTAT3) in AML blasts is an independent prognostic factor for overall survival. Furthermore, phospho-STAT5 (pSTAT5) signaling is increased in primary CD34+ AML stem/progenitors. STAT3/STAT5 activation depends on tyrosine phosphorylation, mediated by several upstream TKs. Inhibition of single upstream TKs did not eliminate LSCs. In contrast, the multi-TK inhibitor Debio 0617B reduced maintenance and self-renewal of primary human AML CD34+ stem/progenitor cells in vitro and in xenotransplantation experiments resulting in long-term elimination of human LSCs and leukemia. Therefore, inhibition of multiple TKs upstream of STAT3/5 may result in sustained therapeutic efficacy of targeted therapy in AML and prevent relapses. Mol Cancer Ther; 16(8); 1497-510. ©2017 AACR.
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Affiliation(s)
| | - Ramin Radpour
- Tumor Immunology, Department of Clinical Research, University of Bern, Bern, Switzerland
| | | | | | - Anne-Laure Huguenin
- Tumor Immunology, Department of Clinical Research, University of Bern, Bern, Switzerland
| | | | - Yara Banz
- Institute of Pathology, University of Bern, Bern, Switzerland
| | - Saumitra Sengupta
- Aurigene Discovery Technologies Limited, Bangalore, Karnataka, India
| | - Michel Aguet
- Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland
| | | | | | | | | | | | - Carsten Riether
- Tumor Immunology, Department of Clinical Research, University of Bern, Bern, Switzerland.
- Department of Medical Oncology, Inselspital, University Hospital and University of Bern, Bern, Switzerland
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Zebrafish as a model for leukemia and other hematopoietic disorders. J Hematol Oncol 2015; 8:29. [PMID: 25884214 PMCID: PMC4389495 DOI: 10.1186/s13045-015-0126-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 03/11/2015] [Indexed: 01/24/2023] Open
Abstract
Zebrafish is an established model for the study of vertebrate development, and is especially amenable for investigating hematopoiesis, where there is strong conservation of key lineages, genes, and developmental processes with humans. Over recent years, zebrafish has been increasingly utilized as a model for a range of human hematopoietic diseases, including malignancies. This review provides an overview of zebrafish hematopoiesis and describes its application as a model of leukemia and other hematopoietic disorders.
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JAK2V617F drives Mcl-1 expression and sensitizes hematologic cell lines to dual inhibition of JAK2 and Bcl-xL. PLoS One 2015; 10:e0114363. [PMID: 25781882 PMCID: PMC4362760 DOI: 10.1371/journal.pone.0114363] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 11/10/2014] [Indexed: 01/14/2023] Open
Abstract
Constitutive activation of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) axis is fundamental to the molecular pathogenesis of a host of hematological disorders, including acute leukemias and myeloproliferative neoplasms (MPN). We demonstrate here that the major JAK2 mutation observed in these diseases (JAK2V617F) enforces Mcl-1 transcription via STAT3 signaling. Targeting this lesion with JAK inhibitor I (JAKi-I) attenuates STAT3 binding to the Mcl-1 promoter and suppresses Mcl-1 transcript and protein expression. The neutralization of Mcl-1 in JAK2V617F-harboring myelodyssplastic syndrome cell lines sensitizes them to apoptosis induced by the BH3-mimetic and Bcl-xL/Bcl-2 inhibitor, ABT-263. Moreover, simultaneously targeting JAK and Bcl-xL/-2 is synergistic in the presence of the JAK2V617F mutation. These findings suggest that JAK/Bcl-xL/-2 inhibitor combination therapy may have applicability in a range of hematological disorders characterized by activating JAK2 mutations.
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Dorritie KA, McCubrey JA, Johnson DE. STAT transcription factors in hematopoiesis and leukemogenesis: opportunities for therapeutic intervention. Leukemia 2013; 28:248-57. [PMID: 23797472 DOI: 10.1038/leu.2013.192] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 05/30/2013] [Accepted: 06/13/2013] [Indexed: 12/14/2022]
Abstract
Signal transducer and activator of transcription (STAT) proteins comprise a family of transcription factors that are activated by cytokines, hormones and growth factors. The activation of STAT proteins plays a key role in the production of mature hematopoietic cells via effects on cellular proliferation, survival and lineage-specific differentiation. Emerging evidence also demonstrates frequent, constitutive activation of STATs in primary leukemia specimens. Moreover, roles for STATs in promoting leukemia development have been delineated in numerous preclinical studies. This review summarizes our current understanding of STAT protein involvement in normal hematopoiesis and leukemogenesis, as well as recent advances in the development and testing of novel STAT inhibitors.
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Affiliation(s)
- K A Dorritie
- Department of Medicine, University of Pittsburgh and the University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
| | - J A McCubrey
- Department of Microbiology and Immunology, School of Medicine, East Carolina University, Greenville, NC, USA
| | - D E Johnson
- Department of Pharmacology and Chemical Biology, University of Pittsburgh and the University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA
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Shin HY, Reich NC. Dynamic trafficking of STAT5 depends on an unconventional nuclear localization signal. J Cell Sci 2013; 126:3333-43. [PMID: 23704351 DOI: 10.1242/jcs.123042] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Signal transducer and activator of transcription 5 (STAT5) is crucial for physiological processes that include hematopoiesis, liver metabolism and mammary gland development. However, aberrant continual activity of STAT5 has been causally linked to human leukemias and solid tumor formation. As a regulated transcription factor, precise cellular localization of STAT5 is essential. Conventional nuclear localization signals consist of short stretches of basic amino acids. In this study, we provide evidence that STAT5 nuclear import is dependent on an unconventional nuclear localization signal that functions within the conformation of an extensive coiled-coil domain. Both in vitro binding and in vivo functional assays reveal that STAT5 nuclear import is mediated by the importin-α3/β1 system independently of STAT5 activation by tyrosine phosphorylation. The integrity of the coiled-coil domain is essential for STAT5 transcriptional induction of the β-casein gene following prolactin stimulation as well as its ability to synergize with the glucocorticoid receptor. The glucocorticoid receptor accumulates in the nucleus in response to prolactin and this nuclear import is dependent on STAT5 nuclear import. STAT5 continually shuttles in and out of the nucleus and live cell imaging demonstrates that STAT5 nuclear export is mediated by both chromosome region maintenance 1 (Crm1)-dependent and Crm1-independent pathways. A Crm1-dependent nuclear export signal was identified within the STAT5 N-terminus. These findings provide insight into the fundamental mechanisms that regulate STAT5 nuclear trafficking and cooperation with the glucocorticoid receptor and provide a basis for clinical intervention of STAT5 function in disease.
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Affiliation(s)
- Ha Youn Shin
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York 11794, USA
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The zebrafish as a tool in leukemia research. Leuk Res 2012; 36:1082-8. [DOI: 10.1016/j.leukres.2012.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 05/14/2012] [Accepted: 06/06/2012] [Indexed: 11/18/2022]
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Comparative proteomics in acute myeloid leukemia. Contemp Oncol (Pozn) 2012; 16:95-103. [PMID: 23788862 PMCID: PMC3687393 DOI: 10.5114/wo.2012.28787] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Revised: 07/25/2011] [Accepted: 02/13/2012] [Indexed: 01/22/2023] Open
Abstract
The term proteomics was used for the first time in 1995 to describe large-scale protein analyses. At the same time proteomics was distinguished as a new domain of the life sciences. The major object of proteomic studies is the proteome, i.e. the set of all proteins accumulating in a given cell, tissue or organ. During the last years several new methods and techniques have been developed to increase the fidelity and efficacy of proteomic analyses. The most widely used are two-dimensional electrophoresis (2DE) and mass spectrometry (MS). In the past decade proteomic analyses have also been successfully applied in biomedical research. They allow one to determine how various diseases affect the pattern of protein accumulation. In this paper, we attempt to summarize the results of the proteomic analyses of acute myeloid leukemia (AML) cells. They have increased our knowledge on the mechanisms underlying AML development and contributed to progress in AML diagnostics and treatment.
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Lin WY, Lee WC. Floating prioritized subset analysis: A powerful method to detect differentially expressed genes. Comput Stat Data Anal 2011. [DOI: 10.1016/j.csda.2010.07.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Modeling the functional heterogeneity of leukemia stem cells: role of STAT5 in leukemia stem cell self-renewal. Blood 2009; 114:3983-93. [PMID: 19667399 DOI: 10.1182/blood-2009-06-227603] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Although the cancer stem cell (CSC) concept implies that CSCs are rare, recent reports suggest that CSCs may be frequent in some cancers. We hypothesized that the proportion of leukemia stem cells would vary as a function of the number of dysregulated pathways. Constitutive expression of MN1 served as a 1-oncogene model, and coexpression of MN1 and a HOX gene served as a 2-oncogene model. Leukemia-initiating cell (LIC) number and in vitro expansion potential of LICs were functionally assessed by limiting dilution analyses. LIC expansion potential was 132-fold increased in the 2- compared with the 1-oncogene model, although phenotypically, both leukemias were similar. The 2-oncogene model was characterized by granulocyte-macrophage colony-stimulating factor (GM-CSF) hypersensitivity and activated STAT/ERK signaling. GM-CSF hypersensitivity of the 2-oncogene model (MN1/HOXA9) was lost in Stat5b(-/-) cells, and the LIC expansion potential was reduced by 86- and 28-fold in Stat5b(-/-) and Stat1(-/-) cells, respectively. Interestingly, in 201 acute myeloid leukemia (AML) patients, coexpression of MN1 and HOXA9 was restricted to patients with the poorest prognosis and was associated with highly active STAT signaling. Our data demonstrate the functional heterogeneity of LICs and show that STAT signaling is critical for leukemia stem cell self-renewal in MN1- and HOXA9-expressing leukemias.
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Benekli M, Baumann H, Wetzler M. Targeting signal transducer and activator of transcription signaling pathway in leukemias. J Clin Oncol 2009; 27:4422-32. [PMID: 19667270 DOI: 10.1200/jco.2008.21.3264] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Signal transducer and activator of transcription (STAT) proteins comprise a seven-member family of latent cytoplasmic transcription factors that are activated through tyrosine phosphorylation by a variety of cytokines and growth factors. Aberrant activation of STATs accompanies malignant cellular transformation with resultant leukemogenesis. Constitutive activation of STATs has been demonstrated in various leukemias. A better understanding of the mechanisms of dysregulation of the STAT pathway and understanding of the cause and effect relationship in leukemogenesis may serve as a basis for designing novel therapeutic strategies directed against STATs. Mechanisms of STAT activation, the potential role of STAT signaling in leukemogenesis, and recent advances in drug discovery targeting the STAT pathway are the focus of this review.
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Affiliation(s)
- Mustafa Benekli
- Department of Medical Oncology, Gazi University Faculty of Medicine, Ankara, Turkey
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Tyner JW, Rutenberg-Schoenberg ML, Erickson H, Willis SG, O'Hare T, Deininger MW, Druker BJ, Loriaux MM. Functional characterization of an activating TEK mutation in acute myeloid leukemia: a cellular context-dependent activating mutation. Leukemia 2009; 23:1345-8. [PMID: 19340004 DOI: 10.1038/leu.2009.66] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Vempati S, Reindl C, Wolf U, Kern R, Petropoulos K, Naidu VM, Buske C, Hiddemann W, Kohl TM, Spiekermann K. Transformation by oncogenic mutants and ligand-dependent activation of FLT3 wild-type requires the tyrosine residues 589 and 591. Clin Cancer Res 2008; 14:4437-45. [PMID: 18628457 DOI: 10.1158/1078-0432.ccr-07-1873] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Mutations in the receptor tyrosine kinase FLT3 are found in up to 30% of acute myelogenous leukemia patients and are associated with an inferior prognosis. In this study, we characterized critical tyrosine residues responsible for the transforming potential of active FLT3-receptor mutants and ligand-dependent activation of FLT3-WT. EXPERIMENTAL DESIGN We performed a detailed structure-function analysis of putative autophosphorylation tyrosine residues in the FLT3-D835Y tyrosine kinase domain (TKD) mutant. All tyrosine residues in the juxtamembrane domain (Y566, Y572, Y589, Y591, Y597, and Y599), interkinase domain (Y726 and Y768), and COOH-terminal domain (Y955 and Y969) of the FLT3-D835Y construct were successively mutated to phenylalanine and the transforming activity of these mutants was analyzed in interleukin-3-dependent Ba/F3 cells. Tyrosine residues critical for the transforming potential of FLT3-D835Y were also analyzed in FLT3 internal tandem duplication mutants (FLT3-ITD)and the FLT3 wild-type (FLT3-WT) receptor. RESULT The substitution of the tyrosine residues by phenylalanine in the juxtamembrane, interkinase, and COOH-terminal domains resulted in a complete loss of the transforming potential of FLT3-D835Y-expressing cells which can be attributed to a significant reduction of signal tranducer and activator of transcription 5 (STAT5) phosphorylation at the molecular level. Reintroduction of single tyrosine residues revealed the critical role of Y589 and Y591 in reconstituting interleukin-3-independent growth of FLT3-TKD-expressing cells. Combined mutation of Y589 and Y591 to phenylalanine also abrogated ligand-dependent proliferation of FLT3-WT and the transforming potential of FLT3-ITD-with a subsequent abrogation of STAT5 phosphorylation. CONCLUSION We identified two tyrosine residues, Y589 and Y591, in the juxtamembrane domain that are critical for the ligand-dependent activation of FLT3-WT and the transforming potential of oncogenic FLT3 mutants.
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Affiliation(s)
- Sridhar Vempati
- GSF-National Research Center for Environment, University of Munich-Grosshadern, Munich, Germany
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18
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Loriaux MM, Levine RL, Tyner JW, Fröhling S, Scholl C, Stoffregen EP, Wernig G, Erickson H, Eide CA, Berger R, Bernard OA, Griffin JD, Stone RM, Lee B, Meyerson M, Heinrich MC, Deininger MW, Gilliland DG, Druker BJ. High-throughput sequence analysis of the tyrosine kinome in acute myeloid leukemia. Blood 2008; 111:4788-96. [PMID: 18252861 PMCID: PMC2343606 DOI: 10.1182/blood-2007-07-101394] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 01/27/2008] [Indexed: 12/20/2022] Open
Abstract
To determine whether aberrantly activated tyrosine kinases other than FLT3 and c-KIT contribute to acute myeloid leukemia (AML) pathogenesis, we used high-throughput (HT) DNA sequence ana-lysis to screen exons encoding the activation loop and juxtamembrane domains of 85 tyrosine kinase genes in 188 AML patients without FLT3 or c-KIT mutations. The screen identified 30 nonsynonymous sequence variations in 22 different kinases not previously reported in single-nucleotide polymorphism (SNP) databases. These included a novel FLT3 activating allele and a previously described activating mutation in MET (METT1010I). The majority of novel sequence variants were stably expressed in factor-dependent Ba/F3 cells. Apart from one FLT3 allele, none of the novel variants showed constitutive phosphorylation by immunoblot analysis and none transformed Ba/F3 cells to factor-independent growth. These findings indicate the majority of these alleles are not potent tyrosine kinase activators in this cellular context and that a significant proportion of nonsynonymous sequence variants identified in HT DNA sequencing screens may not have functional significance. Although some sequence variants may represent SNPs, these data are consistent with recent reports that a significant fraction of such sequence variants are "passenger" rather than "driver" alleles and underscore the importance of functional assessment of candidate disease alleles.
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Affiliation(s)
- Marc M Loriaux
- Division of Hematology and Medical Oncology, Oregon Health & Science University Cancer Institute, Portland, OR 97239, USA
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19
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RNAi screening of the tyrosine kinome identifies therapeutic targets in acute myeloid leukemia. Blood 2007; 111:2238-45. [PMID: 18025156 DOI: 10.1182/blood-2007-06-097253] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Despite vast improvements in our understanding of cancer genetics, a large percentage of cancer cases present without knowledge of the causative genetic events. Tyrosine kinases are frequently implicated in the pathogenesis of numerous types of cancer, but identification and validation of tyrosine kinase targets in cancer can be a time-consuming process. We report the establishment of an efficient, functional screening assay using RNAi technology to directly assess and compare the effect of individually targeting each member of the tyrosine kinase family. We demonstrate that siRNA screening can identify tyrosine kinase targets containing activating mutations in Janus kinase (JAK) 3 (A572V) in CMK cells and c-KIT (V560G) in HMC1.1 cells. In addition, this assay identifies targets that do not contain mutations, such as JAK1 and the focal adhesion kinases (FAK), that are crucial to the survival of the cancer cells. This technique, with additional development, might eventually offer the potential to match specific therapies with individual patients based on a functional assay.
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20
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Vempati S, Reindl C, Kaza SK, Kern R, Malamoussi T, Dugas M, Mellert G, Schnittger S, Hiddemann W, Spiekermann K. Arginine 595 is duplicated in patients with acute leukemias carrying internal tandem duplications of FLT3 and modulates its transforming potential. Blood 2007; 110:686-94. [PMID: 17387224 DOI: 10.1182/blood-2006-10-053181] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstract
FLT3–internal tandem duplications (FLT3-ITDs) comprise a heterogeneous group of mutations in patients with acute leukemias that are prognostically important. To characterize the mechanism of transformation by FLT3-ITDs, we sequenced the juxtamembrane region (JM) of FLT3 from 284 patients with acute leukemias. The length of FLT3-ITDs varied from 2 to 42 amino acids (AAs) with a median of 17 AAs. The analysis of duplicated AAs showed that in the majority of patients, the duplications localize between AAs 591 to 599 (YVDFREYEY). Arginine 595 (R595) within this region is duplicated in 77% of patients. Single duplication of R595 in FLT3 conferred factor-independent growth to Ba/F3 cells and activated STAT5. Moreover, deletion or substitution of the duplicated R595 in 2 FLT3-ITD constructs as well as the deletion of wild-type R595 in FLT3-ITD substantially reduced the transforming potential and STAT5 activation, pointing to a critical role of the positive charge of R595 in stabilizing the active confirmation of FLT3-ITDs. Deletion of R595 in FLT3-WT nearly abrogated the ligand-dependent activation of FLT3-WT. Our data provide important insights into the molecular mechanism of transformation by FLT3-ITDs and show that duplication of R595 is important for the leukemic potential of FLT3-ITDs.
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Affiliation(s)
- Sridhar Vempati
- Clinical Cooperative Group Leukemia, GSF (National Research Center for Environment and Health), Munich, Germany
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21
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O'Sullivan LA, Liongue C, Lewis RS, Stephenson SEM, Ward AC. Cytokine receptor signaling through the Jak–Stat–Socs pathway in disease. Mol Immunol 2007; 44:2497-506. [PMID: 17208301 DOI: 10.1016/j.molimm.2006.11.025] [Citation(s) in RCA: 230] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2006] [Revised: 11/21/2006] [Accepted: 11/22/2006] [Indexed: 12/31/2022]
Abstract
The complexity of multicellular organisms is dependent on systems enabling cells to respond to specific stimuli. Cytokines and their receptors are one such system, whose perturbation can lead to a variety of disease states. This review represents an overview of our current understanding of the cytokine receptors, Janus kinases (Jaks), Signal transducers and activators of transcription (Stats) and Suppressors of cytokine signaling (Socs), focussing on their contribution to diseases of an immune or hematologic nature.
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Affiliation(s)
- Lynda A O'Sullivan
- School of Life & Environmental Sciences, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia
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22
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Gu TL, Mercher T, Tyner JW, Goss VL, Walters DK, Cornejo MG, Reeves C, Popova L, Lee K, Heinrich MC, Rush J, Daibata M, Miyoshi I, Gilliland DG, Druker BJ, Polakiewicz RD. A novel fusion of RBM6 to CSF1R in acute megakaryoblastic leukemia. Blood 2007; 110:323-33. [PMID: 17360941 PMCID: PMC1896120 DOI: 10.1182/blood-2006-10-052282] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Activated tyrosine kinases have been frequently implicated in the pathogenesis of cancer, including acute myeloid leukemia (AML), and are validated targets for therapeutic intervention with small-molecule kinase inhibitors. To identify novel activated tyrosine kinases in AML, we used a discovery platform consisting of immunoaffinity profiling coupled to mass spectrometry that identifies large numbers of tyrosine-phosphorylated proteins, including active kinases. This method revealed the presence of an activated colony-stimulating factor 1 receptor (CSF1R) kinase in the acute megakaryoblastic leukemia (AMKL) cell line MKPL-1. Further studies using siRNA and a small-molecule inhibitor showed that CSF1R is essential for the growth and survival of MKPL-1 cells. DNA sequence analysis of cDNA generated by 5'RACE from CSF1R coding sequences identified a novel fusion of the RNA binding motif 6 (RBM6) gene to CSF1R gene generated presumably by a t(3;5)(p21;q33) translocation. Expression of the RBM6-CSF1R fusion protein conferred interleukin-3 (IL-3)-independent growth in BaF3 cells, and induces a myeloid proliferative disease (MPD) with features of megakaryoblastic leukemia in a murine transplant model. These findings identify a novel potential therapeutic target in leukemogenesis, and demonstrate the utility of phosphoproteomic strategies for discovery of tyrosine kinase alleles.
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MESH Headings
- Animals
- Cell Line
- Cell Line, Tumor
- Cell Proliferation
- Cell Survival
- Chromosomes, Human, Pair 3
- Chromosomes, Human, Pair 5
- Humans
- Leukemia, Megakaryoblastic, Acute/etiology
- Leukemia, Megakaryoblastic, Acute/genetics
- Mice
- Neoplasm Transplantation
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/isolation & purification
- Oncogene Proteins, Fusion/physiology
- Protein-Tyrosine Kinases/isolation & purification
- RNA-Binding Proteins/genetics
- Receptor, Macrophage Colony-Stimulating Factor/genetics
- Receptor, Macrophage Colony-Stimulating Factor/isolation & purification
- Sequence Analysis, DNA
- Translocation, Genetic
- Transplantation, Heterologous
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Affiliation(s)
- Ting-lei Gu
- Cell Signaling Technology, Danvers, MA 01923, USA
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23
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Grandage VL, Everington T, Linch DC, Khwaja A. Gö6976 is a potent inhibitor of the JAK 2 and FLT3 tyrosine kinases with significant activity in primary acute myeloid leukaemia cells. Br J Haematol 2006; 135:303-16. [PMID: 16956345 DOI: 10.1111/j.1365-2141.2006.06291.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Aberrant activation of Janus kinase/signal transducers and activators of transcription (JAK/STAT) signalling is implicated in a number of haematological malignancies and effective JAK inhibitors may be therapeutically useful. We found that Gö6976, an indolocarbazole inhibitor of the calcium-dependent isozymes of protein kinase C (PKC), inhibited interleukin 3/granulocyte-macrophage colony-stimulating factor-induced signalling, proliferation and survival whereas Gö6983, a broad spectrum PKC inhibitor, had no such effects. Gö6976 was found to be a direct and potent inhibitor of JAK2 in vitro. Gö6976 also inhibited signalling, survival and proliferation in cells expressing the leukaemia-associated TEL-JAK2 fusion protein and the myeloproliferative disorder (MPD)-associated JAK2 V617F mutant. In primary acute myeloid leukaemia (AML) cells, incubation with Gö6976 reduced constitutive STAT activity in all cases studied. In addition, Akt and mitogen-activated protein kinase phosphorylation were reduced in 4/5 FLT3-internal tandem duplication (ITD) positive AML cases and 7/13 FLT3-wild-type (WT) cases. Expression of FLT3-WT, ITD and D835Y in 32D cells showed that Gö6976 is also a potent inhibitor of WT and mutant FLT3. In AML cells, Gö6976 reduced the survival to 55 +/- 5% of control in FLT3-ITD cases and to 69 +/- 5% in FLT3-WT samples. These data may help identify clinically useful compounds based on the structure of Gö6976, which can be employed for the treatment of MPDs as well as AML.
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Affiliation(s)
- Victoria L Grandage
- Department of Haematology, Royal Free and University College London Medical School, London, UK
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24
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Ilaria RL. AML: Many new tools for discovery, not enough answers (yet). Leuk Res 2006; 30:1073-5. [PMID: 16603241 DOI: 10.1016/j.leukres.2006.02.024] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2006] [Revised: 02/21/2006] [Accepted: 02/24/2006] [Indexed: 11/24/2022]
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25
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Walters DK, Goss VL, Stoffregen EP, Gu TL, Lee K, Nardone J, McGreevey L, Heinrich MC, Deininger MW, Polakiewicz R, Druker BJ. Phosphoproteomic analysis of AML cell lines identifies leukemic oncogenes. Leuk Res 2006; 30:1097-104. [PMID: 16464493 DOI: 10.1016/j.leukres.2006.01.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 12/06/2005] [Accepted: 01/03/2006] [Indexed: 10/25/2022]
Abstract
STAT5 is constitutively phosphorylated in leukemic cells in approximately 70% of acute myeloid leukemia (AML) patients. To identify kinase candidates potentially responsible for STAT5 phosphorylation, we used liquid chromatography-tandem mass spectrometry (LC-MS/MS) mass spectrometry to detect phosphoproteins in AML cell lines. We established TEL-ARG and BCR-ABL fusion proteins as the mechanism underlying STAT5 phosphorylation in HT-93 and KBM-3 cells, respectively. In addition, we identified a JAK2 pseudokinase domain mutation in HEL cells and using siRNA downregulation, established JAK2 as the kinase responsible for phosphorylating STAT5. This study illustrates the benefit of LC-MS/MS mass spectrometry and siRNA for the identification of novel targets and mutations.
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Affiliation(s)
- Denise K Walters
- Department of Hematology and Oncology, Howard Hughes Medical Institute, Oregon Health and Science University Cancer Institute, 3181 Sam Jackson Park Road, and Portland VA Medical Center, Portland, OR 97239, USA.
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26
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Walters DK, Mercher T, Gu TL, O'Hare T, Tyner JW, Loriaux M, Goss VL, Lee KA, Eide CA, Wong MJ, Stoffregen EP, McGreevey L, Nardone J, Moore SA, Crispino J, Boggon TJ, Heinrich MC, Deininger MW, Polakiewicz RD, Gilliland DG, Druker BJ. Activating alleles of JAK3 in acute megakaryoblastic leukemia. Cancer Cell 2006; 10:65-75. [PMID: 16843266 DOI: 10.1016/j.ccr.2006.06.002] [Citation(s) in RCA: 242] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 04/21/2006] [Accepted: 06/01/2006] [Indexed: 12/18/2022]
Abstract
Tyrosine kinases are aberrantly activated in numerous malignancies, including acute myeloid leukemia (AML). To identify tyrosine kinases activated in AML, we developed a screening strategy that rapidly identifies tyrosine-phosphorylated proteins using mass spectrometry. This allowed the identification of an activating mutation (A572V) in the JAK3 pseudokinase domain in the acute megakaryoblastic leukemia (AMKL) cell line CMK. Subsequent analysis identified two additional JAK3 alleles, V722I and P132T, in AMKL patients. JAK3(A572V), JAK3(V722I), and JAK3(P132T) each transform Ba/F3 cells to factor-independent growth, and JAK3(A572V) confers features of megakaryoblastic leukemia in a murine model. These findings illustrate the biological importance of gain-of-function JAK3 mutations in leukemogenesis and demonstrate the utility of proteomic approaches to identifying clinically relevant mutations.
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MESH Headings
- Alleles
- Animals
- Apoptosis/drug effects
- Benzamides
- Cell Line, Tumor
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Humans
- Imatinib Mesylate
- Janus Kinase 2
- Janus Kinase 3
- K562 Cells
- Leukemia, Experimental/genetics
- Leukemia, Experimental/metabolism
- Leukemia, Experimental/pathology
- Leukemia, Megakaryoblastic, Acute/genetics
- Leukemia, Megakaryoblastic, Acute/metabolism
- Leukemia, Megakaryoblastic, Acute/pathology
- Mice
- Mice, Inbred C57BL
- Models, Molecular
- Mutant Proteins/chemistry
- Mutant Proteins/genetics
- Mutant Proteins/metabolism
- Phosphorylation/drug effects
- Piperazines/pharmacology
- Protein Kinase Inhibitors/pharmacology
- Protein Structure, Tertiary/genetics
- Protein-Tyrosine Kinases/antagonists & inhibitors
- Protein-Tyrosine Kinases/genetics
- Protein-Tyrosine Kinases/metabolism
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Pyrimidines/pharmacology
- RNA, Small Interfering/genetics
- TYK2 Kinase
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27
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Lewis RS, Stephenson SEM, Ward AC. Constitutive activation of zebrafish Stat5 expands hematopoietic cell populations in vivo. Exp Hematol 2006; 34:179-87. [PMID: 16459186 DOI: 10.1016/j.exphem.2005.11.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 10/18/2005] [Accepted: 11/03/2005] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Constitutive activation of Stat5 has been observed in a variety of malignancies, particularly myeloid leukemias. To directly investigate the in vivo consequences of Stat5 perturbation, we expressed constitutively active forms in zebrafish. METHODS We generated mutants of the zebrafish stat5.1 protein (N646H, H298R/N714F, and N714F) based on previously identified constitutively active mutants of murine Stat5a. The in vitro properties of these mutants were determined using phosphorylation-specific antibodies and luciferase reporter assays, and their in vivo effects were analyzed through microinjection of zebrafish embryos. RESULTS Two of these stat5.1 mutants (N646H and H298R/N714F) showed increased tyrosine phosphorylation and transactivation activity compared to the wild-type protein. Expression of either mutant led to a range of hematological perturbations, which were more pronounced for the H298R/N714F mutant. Interestingly, expression of wild-type also produced generally similar phenotypes. Further analysis showed that expression of the H298R/N714F mutant led to increased numbers of early and late myeloid cells, erythrocytes, and B cells. Some nonhematopoietic developmental perturbations were also observed, but these were equally prominent with wild-type or mutant forms. CONCLUSION These data implicate Stat5 activity as a direct critical regulator of hematological cell proliferation, suggesting a causal role for constitutively-active Stat5 in the etiology of hematological malignancies.
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Affiliation(s)
- Rowena S Lewis
- Centre for Cellular and Molecular Biology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia
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28
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Higashi T, Tsukada J, Yoshida Y, Mizobe T, Mouri F, Minami Y, Morimoto H, Tanaka Y. Constitutive tyrosine and serine phosphorylation of STAT4 in T-cells transformed with HTLV-I. Genes Cells 2005; 10:1153-62. [PMID: 16324152 DOI: 10.1111/j.1365-2443.2005.00912.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
STAT4 is a critical mediator of IL-12-stimulated gene regulation in T-helper type 1 (Th1) cell. IL-12 activates the Janus family tyrosine kinases JAK2 and Tyk2, which in turn phosphorylate STAT4 on tyrosine 693. The p38 mitogen-activated protein kinase (MAPK) signaling pathway is also activated in response to IL-12, followed by phosphorylation of STAT4 on serine 721, which is required for STAT4 full transcriptional activity. In the present study, we demonstrated constitutive activation of STAT4 in HTLV-I-transformed T-cell lines MT-2, MT-4 and HUT102 by immunoprecipitation, Western blotting and electrophoretic mobility shift assay (EMSA). In HTLV-I-transformed T-cell lines, STAT4 was constitutively phosphorylated not only on tyrosine 693 but also on serine 721, and formed a heterodimer with STAT3. Constitutive phosphorylation of its upstream activators, JAK2, Tyk2 and p38 MAPK was also observed in the cells. EMSA and transient transfection studies further showed that the high-affinity sis-inducible element (hSIE) preferentially binds the STAT3/STAT4 heterodimer and is constitutively transactivated in MT-2 cells in the absence of exogenous cytokine stimulation. When STAT4 expression vector was cotransfected along with STAT3 expression vector into MT-2 cells, STAT4 significantly synergized with STAT3 to transactivate hSIE, showing the functional importance of heterodimer formation between STAT4 and STAT3.
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Affiliation(s)
- Takehiro Higashi
- The First Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
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29
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Steffen B, Müller-Tidow C, Schwäble J, Berdel WE, Serve H. The molecular pathogenesis of acute myeloid leukemia. Crit Rev Oncol Hematol 2005; 56:195-221. [PMID: 16236521 DOI: 10.1016/j.critrevonc.2004.10.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2004] [Revised: 09/30/2004] [Accepted: 10/28/2004] [Indexed: 10/25/2022] Open
Abstract
The description of the molecular pathogenesis of acute myeloid leukemias (AML) has seen dramatic progress over the last years. Two major types of genetic events have been described that are crucial for leukemic transformation: alterations in myeloid transcription factors governing hematopoietic differentiation and activating mutations of signal transduction intermediates. These processes are highly interdependent, since the molecular events changing the transcriptional control in hematopoietic progenitor cells modify the composition of signal transduction molecules available for growth factor receptors, while the activating mutations in signal transduction molecules induce alterations in the activity and expression of several transcription factors that are crucial for normal myeloid differentiation. The purpose of this article is to review the current literature describing these genetic events, their biological consequences and their clinical implications. As the article will show, the recent description of several critical transforming mutations in AML may soon give rise to more efficient and less toxic molecularly targeted therapies of this deadly disease.
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Affiliation(s)
- Björn Steffen
- Department of Medicine, Hematology/Oncology, University of Münster, Albert-Schweitzer-Strasse 33, 48129 Münster, Germany
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30
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Moucadel V, Constantinescu SN. Differential STAT5 signaling by ligand-dependent and constitutively active cytokine receptors. J Biol Chem 2005; 280:13364-73. [PMID: 15677477 DOI: 10.1074/jbc.m407326200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Many leukemia and cancer cells exhibit constitutive activation of STAT5, which was suggested to provide an anti-apoptotic advantage. Transformation of cytokine-dependent hematopoietic cells, such as Ba/F3 cells to autonomous growth and tumorigenicity equally results in selection for constitutive activation of STAT5. We compared STAT5 signaling between erythropoietin(Epo)-dependent cells and cells that were transformed by oncogenic activation of the erythropoietin receptor (EpoR) by coexpression of the gp55-P envelope protein of the spleen focus forming virus or by expression of the R129C constitutively active EpoR mutant. In transformed cells it was mainly STAT5B that was constitutively activated. In contrast, Epo stimulation activated both STAT5A and STAT5B. In transformed cells, chromatin immunoprecipitation (ChIP) showed STAT5 to be physically bound to promoters of STAT5 target genes, such as Bcl(XL), and to be able to promote transactivation of the Bcl(XL) promoter in a constitutive fashion. Sequencing of native sequences after ChIP with anti-STAT5 antibodies in Epo-dependent and -transformed cells indicated that in gp55-transformed cells, STAT5B bound in the chromatin not only to N3 high affinity, but also to low affinity N4 GAS sites. Transactivation for N3 GAS sites in luciferase reporters was specific to gp55 transformation. Because we also found preferential constitutive STAT5B activation after transformation of cells by a truncated form of the G-CSF-R that produces severe neutropenia (Kostmann syndrome) and favors leukemia in humans, we discuss the potential role of STAT5B in oncogenic transformation of hematopoietic cells.
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31
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Baśkiewicz-Masiuk M, Machaliński B. The role of the STAT5 proteins in the proliferation and apoptosis of the CML and AML cells. Eur J Haematol 2004; 72:420-9. [PMID: 15128421 DOI: 10.1111/j.1600-0609.2004.00242.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The STAT5 proteins are activated by many haematological cytokines and growth factors. They regulate cell cycle, apoptosis and proliferation of different cells via the influence on gene transcription. Because STAT5s are constitutively activated in certain haematooncologic diseases, they are suggested to play an important role in leukaemogenesis. However, the real function of these proteins in haematopoietic cell transformation and proliferation is not clear enough. The aim of this study was to evaluate the influence of suppression of STAT5A and STAT5B expression on the clonogenicity and apoptosis of the chronic myeloid leukaemia (CML) and acute myeloid leukaemia (AML) cells. MATERIAL AND METHODS Blast cells from 34 newly diagnosed patients with CML and AML were used in our experiments. Antisense oligodeoxynucleotides (ODNs) were applied to block STAT5A and STAT5B at the mRNA level and the RT-PCR method was used to study STAT5 mRNA expression in the cells after incubation with ODNs. Moreover, Western blot analysis of the STAT5 proteins was performed. The effect of ODN pretreatment on cell clonogenicity in methylocellulose cultures was examined according to the type of oligodeoxynucleotide and the time of exposure. The induction of apoptosis in cells was also estimated by the Annexin V/PI staining and the TUNEL method using flow cytometry. RESULTS Perturbation of STAT5 expression decreased proliferative potential of the CML and the AML blasts as well as enhanced their apoptosis (P < 0.05). CONCLUSIONS Our studies showed that the STAT5 proteins may be critical in the regulation of growth and apoptosis of the CML and AML leukaemic cells.
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32
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Ikezoe T, Saito T, Bandobashi K, Yang Y, Koeffler HP, Taguchi H. HIV-1 protease inhibitor induces growth arrest and apoptosis of human multiple myeloma cells via inactivation of signal transducer and activator of transcription 3 and extracellular signal-regulated kinase 1/2. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.473.3.4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
We previously showed that HIV-1 protease inhibitors slowed the proliferation of human myeloid leukemia cells and enhanced their differentiation in the presence of all-trans retinoic acid (ATRA). In this study, we found that protease inhibitors, including ritonavir, saquinavir, and nelfinavir, but not indinavir, induced growth arrest and apoptosis of U266, RPMI8226, and ARH77 human multiple myeloma (MM) cells in association with down-regulation of antiapoptotic protein Mcl-1. Also, protease inhibitors inhibited the survival of freshly isolated MM cells from patients. In contrast, these protease inhibitors did not affect survival of normal B cells and colony formation of myeloid committed stem cells (CFU-GM) from healthy volunteers. In addition, we found that all of the protease inhibitors, except for indinavir, blocked interleukin-6 (IL-6)-stimulated phosphorylation of both signal transducer and activator of transcription 3 (STAT 3) and extracellular signal-regulated kinase 1/2 in U266 and RPMI8226 MM cells. Moreover, the protease inhibitors inhibited both the basal and IL-6-stimulated STAT 3/DNA binding activity in U266 cells as measured by an ELISA-based assay. Furthermore, ritonavir inhibited production of vascular endothelial growth factor one of the targets of STAT 3, in U266 and RPMI8226 cells as measured by ELISA. Taken together, protease inhibitors might be useful for treatment of individuals with MM.
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Affiliation(s)
- Takayuki Ikezoe
- 1Department of Internal Medicine, Kochi Medical School, Nankoku, Kochi, Japan and
| | - Tsuyako Saito
- 1Department of Internal Medicine, Kochi Medical School, Nankoku, Kochi, Japan and
| | - Kentaro Bandobashi
- 1Department of Internal Medicine, Kochi Medical School, Nankoku, Kochi, Japan and
| | - Yang Yang
- 1Department of Internal Medicine, Kochi Medical School, Nankoku, Kochi, Japan and
| | - H. Phillip Koeffler
- 2Division of Hematology/Oncology, Cedars-Sinai Research Institute, UCLA School of Medicine, Los Angeles, CA
| | - Hirokuni Taguchi
- 1Department of Internal Medicine, Kochi Medical School, Nankoku, Kochi, Japan and
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33
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Sternberg DW, Gilliland DG. The Role of Signal Transducer and Activator of Transcription Factors in Leukemogenesis. J Clin Oncol 2004; 22:361-71. [PMID: 14722044 DOI: 10.1200/jco.2004.10.124] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human leukemias are frequently associated with the aberrant expression of activated fusion tyrosine kinases or activated protein tyrosine kinases carrying insertional or point mutations. The activated kinase enzymes typically phosphorylate one or more signal transducer and activator of transcription (STAT) factors, which translocate to the cell nucleus and regulate the expression of genes associated with survival and proliferation. The phosphorylation and activation of STAT family members has been described in a wide range of human leukemias. Furthermore, animal models of leukemia have demonstrated the pivotal contribution of STAT activation to leukemic pathogenesis. This review discusses evidence for the functional importance of STAT activation in the biology of leukemia and current opportunities for modulating STAT proteins in the therapy of this group of diseases.
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Affiliation(s)
- David W Sternberg
- Hematology Division, Brigham and Women's Hospital, Boston, MA 02115, USA.
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Baśkiewicz-Masiuk M, Masiuk M, Machaliński B. The influence of STAT5 antisense oligonucleotides on the proliferation and apoptosis of selected human leukaemic cell lines. Cell Prolif 2003; 36:265-78. [PMID: 14521520 PMCID: PMC6495883 DOI: 10.1046/j.1365-2184.2003.00283.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The signal transducers and activators of transcription--STAT5A and STAT5B--take part in the regulation of many essential physiopathological processes. They influence the cell cycle, apoptosis and the proliferation of different types of cell lines. The STAT5 proteins are induced in response to multiple haematopoietic cytokines. Because they are constitutively active in certain haemato-oncologic diseases, it is also suggested that they play an important role in leukaemogenesis. However, function of these proteins in haematopoietic cell transformation and proliferation is not clear. The aim of this study was to evaluate the impact of perturbation of STAT5 expression [using oligodeoxynucleotide (ODN) against STAT5 mRNA], on the clonogenicity and survival of selected human leukaemic cell lines, HEL, HL-60, K562, TF-1. We analysed the effect of ODN pre-treatment on the cell clonogenicity in methylcellulose cultures according to the time and the temperature of exposure. Moreover, we attempted to estimate apoptosis induced in examined cells, by flow cytometry using combined Annexin V-PI staining and the TUNEL method. We also applied the RT-PCR method to analyse Bax and Bcl-xL gene expression. We found that the perturbation of STAT5 expression with antisense oligonucleotides caused a decrease in the proliferative potential of human K562 and TF-1 cell lines. Also, we observed higher induction of apoptotic cell death in the K562 and TF-1 cells incubated with the antisense STAT5A ODNs. We did not notice any impact of ODNs on the HL-60 and HEL cells. Our studies using STAT5 antisense oligonucleotides showed that these proteins may be critical in the regulation of growth and apoptosis of some types of leukaemic blasts.
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Affiliation(s)
- M Baśkiewicz-Masiuk
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland.
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MESH Headings
- ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism
- Animals
- Apoptosis
- Cytokines/metabolism
- Drug Resistance, Multiple
- Drug Resistance, Neoplasm
- Humans
- Leukemia, Myeloid, Acute/drug therapy
- Leukemia, Myeloid, Acute/pathology
- Mice
- Mice, SCID
- Neovascularization, Pathologic
- Phenotype
- Stromal Cells/metabolism
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Affiliation(s)
- Michael Andreeff
- Section of Molecular Hematology and Therapy, Department of Blood and Marrow Transplantation, University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Benekli M, Baer MR, Baumann H, Wetzler M. Signal transducer and activator of transcription proteins in leukemias. Blood 2003; 101:2940-54. [PMID: 12480704 DOI: 10.1182/blood-2002-04-1204] [Citation(s) in RCA: 242] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Signal transducer and activator of transcription (STAT) proteins are a 7-member family of cytoplasmic transcription factors that contribute to signal transduction by cytokines, hormones, and growth factors. STAT proteins control fundamental cellular processes, including survival, proliferation, and differentiation. Given the critical roles of STAT proteins, it was hypothesized that inappropriate or aberrant activation of STATs might contribute to cellular transformation and, in particular, leukemogenesis. Constitutive activation of mutated STAT3 has in fact been demonstrated to result in transformation. STAT activation has been extensively studied in leukemias, and mechanisms of STAT activation and the potential role of STAT signaling in leukemogenesis are the focus of this review. A better understanding of mechanisms of dysregulation of STAT signaling pathways may serve as a basis for designing novel therapeutic strategies that target these pathways in leukemia cells.
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Affiliation(s)
- Mustafa Benekli
- Leukemia Section, Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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Sauane M, Gopalkrishnan RV, Sarkar D, Su ZZ, Lebedeva IV, Dent P, Pestka S, Fisher PB. MDA-7/IL-24: novel cancer growth suppressing and apoptosis inducing cytokine. Cytokine Growth Factor Rev 2003; 14:35-51. [PMID: 12485618 DOI: 10.1016/s1359-6101(02)00074-6] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The melanoma differentiation-associated gene-7 (mda-7) was cloned by subtraction hybridization as a molecule whose expression is elevated in terminally differentiated human melanoma cells. Current information based on structural and sequence homology, has led to the recognition of MDA-7 as an IL-10 family cytokine member and its renaming as IL-24. Northern blot analysis revealed mda-7/IL-24 expression in human tissues associated with the immune system such as spleen, thymus, peripheral blood leukocytes and normal melanocytes. The MDA-7/IL-24 mouse counterpart, FISP, appears to be a Th2-specific protein and the rat counterpart, C49A/MOB-5, is associated with wound healing and is also induced as a consequence of ras-transformation. A notable property of MDA-7/IL-24 is its ability to induce apoptosis in a large spectrum of human cancer derived cell lines, in mouse xenografts and upon intratumoral injection in human tumors (phase I clinical trials). Various aspects of this intriguing molecule including its cytokine and anti-tumoral effects are described and discussed.
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Affiliation(s)
- Moira Sauane
- Department of Pathology, Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University, BB-1501, 630 West 168th Street, New York, NY 10032, USA.
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38
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Zheng R, Friedman AD, Small D. Targeted inhibition of FLT3 overcomes the block to myeloid differentiation in 32Dcl3 cells caused by expression of FLT3/ITD mutations. Blood 2002; 100:4154-61. [PMID: 12393674 DOI: 10.1182/blood-2002-03-0936] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Internal tandem duplication (ITD) mutations of the juxtamembrane domain-coding sequence of the FLT3 gene are found in up to 34% of patients with acute myeloid leukemia (AML) and are associated with a poor prognosis. FLT3/ITDs result in constitutive activation of the tyrosine kinase domain and transform growth factor-dependent cell lines. FLT3 activation leads to antiapoptotic and proliferative signals, but little is known about the impact of FLT3/ITDs on differentiation. This study was designed to investigate the effect of FLT3/ITD expression on the differentiation of the 32Dcl3 (32D) myeloblastic cell line to neutrophils in response to granulocyte colony-stimulating factor (G-CSF). Expression of FLT3/ITD completely blocked morphologic differentiation and induction of myeloperoxidase (MPO), lysozyme, and CCAAT/enhancer-binding protein epsilon (C/EBPepsilon) in response to G-CSF. Wild-type FLT3 and vector-transfected 32D cells were able to differentiate, although the maturation of FLT3-transfected cells was delayed by FLT3 ligand (FL) stimulation. CEP-701, a potent FLT3 tyrosine kinase inhibitor, overcame the morphologic block in differentiation caused by FLT3/ITD expression and allowed G-CSF induction of myeloid maturation markers. These findings suggest that blocking differentiation may be one of the mechanisms by which FLT3/ITDs contribute to leukemogenesis. CEP-701 and other FLT3 inhibitors may be useful for overcoming the block to differentiation (as well as the block to apoptosis) in the leukemic cells of patients with AML.
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Affiliation(s)
- Rui Zheng
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Testa U, Riccioni R, Militi S, Coccia E, Stellacci E, Samoggia P, Latagliata R, Mariani G, Rossini A, Battistini A, Lo-Coco F, Peschle C. Elevated expression of IL-3Ralpha in acute myelogenous leukemia is associated with enhanced blast proliferation, increased cellularity, and poor prognosis. Blood 2002; 100:2980-8. [PMID: 12351411 DOI: 10.1182/blood-2002-03-0852] [Citation(s) in RCA: 242] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We have investigated the expression of interleukin-3 receptor alpha (IL-3Ralpha) chain in primary blasts from 79 patients with acute myeloid leukemia (AML), 25 patients with B-acute lymphoid leukemia (B-ALL), and 7 patients with T-acute lymphoid leukemia (T-ALL) to evaluate a linkage between the expression of this receptor chain, blast proliferative status, and disease prognosis. Although IL-3Ralpha chain was scarcely expressed in most patients with T-ALL, it was overexpressed in 40% and 45% of patients with B-ALL and AML, respectively, compared with the levels observed in normal CD34(+) progenitors. The biological and clinical significance of this overexpression pattern was investigated in AML. At the biological level, elevated IL-3Ralpha expression was associated with peculiar properties of leukemic blasts, specifically in 3 areas. First, in all patients the blasts expressing elevated IL-3Ralpha levels exhibited higher cycling activity and increased resistance to apoptosis triggered by growth factor deprivation. Second, spontaneous signal transducer and activator of transcription 5 (Stat5) phosphorylation was observed in 13% of AML patients, all pertaining to the group of patients exhibiting high IL-3Ralpha expression. Third, following IL-3 treatment, Stat5 was activated at higher levels in blasts with elevated IL-3Ralpha expression. At the clinical level, a significant correlation was observed between the level of IL-3Ralpha expression and the number of leukemic blasts at diagnosis, and patients exhibiting elevated IL-3Ralpha levels had a lower complete remission rate and survival duration than those showing normal IL-3Ralpha levels. These findings suggest that in AML, deregulated expression of IL-3Ralpha may contribute to the proliferative advantage of the leukemic blasts and, hence, to a poor prognosis.
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MESH Headings
- Adult
- Aged
- Antigens, Surface/analysis
- Apoptosis
- Blast Crisis
- Cell Cycle
- Gene Expression Regulation, Neoplastic
- Humans
- Interleukin-3 Receptor alpha Subunit
- Leukemia, Erythroblastic, Acute/genetics
- Leukemia, Myeloid, Acute/genetics
- Leukemia, Myeloid, Acute/immunology
- Leukemia, Myeloid, Acute/mortality
- Leukemia, Myeloid, Acute/pathology
- Middle Aged
- Predictive Value of Tests
- Prognosis
- Receptors, Interleukin-3/genetics
- Recurrence
- Reference Values
- Reverse Transcriptase Polymerase Chain Reaction
- Survival Rate
- Tumor Cells, Cultured
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Affiliation(s)
- Ugo Testa
- Departments of Hematology and Oncology, Virology, and Immunology, Istituto Superiore di Sanità, Rome, Italy.
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Levis M, Allebach J, Tse KF, Zheng R, Baldwin BR, Smith BD, Jones-Bolin S, Ruggeri B, Dionne C, Small D. A FLT3-targeted tyrosine kinase inhibitor is cytotoxic to leukemia cells in vitro and in vivo. Blood 2002; 99:3885-91. [PMID: 12010785 DOI: 10.1182/blood.v99.11.3885] [Citation(s) in RCA: 354] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Constitutively activating internal tandem duplication (ITD) and point mutations of the receptor tyrosine kinase FLT3 are present in up to 41% of patients with acute myeloid leukemia (AML). These FLT3/ITD mutations are likely to be important because their presence is associated with a poor prognosis. Both types of mutations appear to activate the tyrosine kinase activity of FLT3. We describe here the identification and characterization of the indolocarbazole derivative CEP-701 as a FLT3 inhibitor. This drug potently and selectively inhibits autophosphorylation of wild-type and constitutively activated mutant FLT3 in vitro in FLT3/ITD-transfected cells and in human FLT3-expressing myeloid leukemia-derived cell lines. We demonstrate that CEP-701 induces a cytotoxic effect on cells in a dose-responsive fashion that parallels the inhibition of FLT3. STAT5 and ERK1/2, downstream targets of FLT3 in the signaling pathway, are inhibited in response to FLT3 inhibition. In primary leukemia blasts from AML patients harboring FLT3/ITD mutations, FLT3 is also inhibited, with an associated cytotoxic response. Finally, using a mouse model of FLT3/ITD leukemia, we demonstrate that the drug inhibits FLT3 phosphorylation in vivo and prolongs survival. These findings form the basis for a planned clinical trial of CEP-701 in patients with AML harboring FLT3- activating mutations.
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Affiliation(s)
- Mark Levis
- Johns Hopkins University School of Medicine, Department of Oncology, Baltimore, MD 21231-1000, USA
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41
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Leong PL, Xi S, Drenning SD, Dyer KF, Wentzel AL, Lerner EC, Smithgall TE, Grandis JR. Differential function of STAT5 isoforms in head and neck cancer growth control. Oncogene 2002; 21:2846-53. [PMID: 11973644 DOI: 10.1038/sj.onc.1205385] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2001] [Revised: 01/31/2002] [Accepted: 02/07/2002] [Indexed: 11/08/2022]
Abstract
Up-regulation of the epidermal growth factor receptor (EGFR) is critical for the loss of growth control in a variety of human cancers, including squamous cell carcinoma of the head and neck (SCCHN). Stimulation of EGFR results in activation of mitogenic signaling pathways including Signal Transducers and Activators of Transcription (STATs). Stat5 activation has been primarily demonstrated in hematopoietic malignancies. Gene disruption studies suggest potentially distinct functions of the Stat5 isoforms, Stat5a and Stat5b, which are encoded by two genes closely linked on human chromosome 17. To determine the function of Stat5 in SCCHN growth control, we studied the expression and constitutive activation of Stat5a and Stat5b in normal and transformed human squamous epithelial cells. Increased constitutive activation of Stat5 was detected in transformed compared with normal squamous cells. Blockade of TGF-alpha or EGFR, abrogated Stat5 activation. Targeting of Stat5b using antisense oligonucleotides inhibited SCCHN growth. In addition, SCCHN cells stably transfected with dominant negative mutant Stat5b failed to proliferate in vitro. In contrast, targeting of Stat5a using either antisense or dominant negative strategies had no effect on cell growth. These results suggest that TGF-alpha/EGFR-mediated autocrine growth of transformed epithelial cells is dependent on activation of Stat5b but not Stat5a.
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Affiliation(s)
- Paul L Leong
- Department of Otolaryngology, The University of Pittsburgh School of Medicine and The University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania, USA
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42
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Spiekermann K, Pau M, Schwab R, Schmieja K, Franzrahe S, Hiddemann W. Constitutive activation of STAT3 and STAT5 is induced by leukemic fusion proteins with protein tyrosine kinase activity and is sufficient for transformation of hematopoietic precursor cells. Exp Hematol 2002; 30:262-71. [PMID: 11882364 DOI: 10.1016/s0301-472x(01)00787-1] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
OBJECTIVE Signal transducers and activators of transcription (STAT) factors are critical mediators in the signal transduction of cytokine receptors. In hematopoietic and epithelial cells, activation of STAT 1 induces apoptosis and growth arrest, whereas activation of STAT3 and STAT5 transduces growth-promoting signals. We and others have previously described a high expression and constitutive activation of STAT1, 3, and 5 in AML blasts. In this report we focused on the mechanisms and also the biologic relevance of STAT activation in AML.Results. RESULTS We report here that a constitutive STAT activation can be detected in up to 95% of primary AML blasts. In vitro, neither induction of the leukemic fusion protein PML-RAR alpha in U937 cells nor expression of transforming ras-mutants, but several leukemic protein tyrosine kinase (PTK), strongly induced activation of STAT3 and 5. Stable transfection of BA/F3 cells with TEL-JAK2, TEL-ABL, and BCR-ABL resulted in IL-3 independent growth and strong activation of STAT3 and STAT5 by TEL-JAK2 and TEL-ABL, but not by BCR-ABL. In addition, expression of constitutive active mutants of STAT3 and STAT5 alone were sufficient to transform BA/F3 cells. CONCLUSIONS These results show that STAT3 and STAT5 are activated in the majority of primary AML blasts and are major targets of leukemic fusion proteins with PTK activity. However, the STAT activation pattern by leukemic PTKs differed significantly and might reflect their transforming potential in acute (TEL-JAK2 and TEL-ABL) and chronic leukemias (p210BCR-ABL). The transforming capacity of constitutively activated STAT3 and STAT5 mutants strongly supports their fundamental role in the process of malignant transformation in hematopoietic cells.
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Affiliation(s)
- Karsten Spiekermann
- Department of Medicine III, University Hospital Grosshadern, LMU and GSF, Clinical Cooperative Group Leukemia, Munich, Germany.
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43
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Benekli M, Xia Z, Donohue KA, Ford LA, Pixley LA, Baer MR, Baumann H, Wetzler M. Constitutive activity of signal transducer and activator of transcription 3 protein in acute myeloid leukemia blasts is associated with short disease-free survival. Blood 2002; 99:252-7. [PMID: 11756179 DOI: 10.1182/blood.v99.1.252] [Citation(s) in RCA: 137] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Signal transducer and activator of transcription (STAT) proteins are involved in hematopoietic cytokine receptor signaling pathways that regulate cell proliferation, differentiation, and survival. STATs are dysregulated in acute myeloid leukemia (AML); mechanisms of dysregulation include constitutive activation and truncation of the C-terminal transactivation domain; the latter results in a beta isoform that has a trans-dominant negative effect on gene induction mediated by the full-length STAT alpha form. It was hypothesized that constitutive STAT activity might correlate with unfavorable treatment outcome in AML. Pretreatment bone marrow samples from 63 adult patients with AML were analyzed by electrophoretic mobility shift assay for the presence of STAT DNA-binding activity. Isoforms and relative levels of STAT proteins were determined by immunoblotting. Constitutive STAT3 activity was detected in samples from 28 (44%) patients. Pretreatment clinical characteristics, expression of STAT alpha/beta isoforms, and treatment regimens did not differ significantly between patients with and without constitutive STAT3 activity. Disease-free survival (DFS) was significantly shorter in patients with than in patients without constitutive STAT3 activity (median 8.7 vs 20.6 months; P =.01). Overall survival did not differ significantly. The subgroup of patients with constitutive STAT3 activity and the STAT3 beta isoform had the shortest DFS (P =.006) and shorter overall survival (P =.049) than all other patients. Whether adverse treatment outcome is attributable to constitutive STAT activity itself or to a process that leads to constitutive STAT activity remains to be determined. This is the first demonstration of a prognostic significance for STAT proteins in a malignancy.
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Affiliation(s)
- Mustafa Benekli
- Leukemia Section, Department of Medicine, Roswell Park Cancer Institute, Buffalo, NY 14263, USA
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Spiekermann K, Biethahn S, Wilde S, Hiddemann W, Alves F. Constitutive activation of STAT transcription factors in acute myelogenous leukemia. Eur J Haematol 2001. [PMID: 11722592 DOI: 10.1034/j.1600-0609.2001.t01-1-00385.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Hematopoietic growth factors (HGF) are essential for proliferation and differentiation of hematopoietic precursors and activate a distinct set of JAK-STAT (Janus kinases-signal transducers and activators of transcription) proteins. Previous results from our group have shown a strong expression of JAK-STAT proteins in primary acute myelogenous leukemia (AML) blasts and AML cell lines. Here, we asked whether a constitutive activation of the JAK-STAT pathway might be involved in the pathogenesis of AML. We could demonstrate a constitutive activation of STAT1, 3 and 5 by immunoprecipitation of the tyrosine phosphorylated proteins in different human AML cell lines. Three patterns of STAT activation were found: (I) activation of only STAT1, (II) activation of STAT1 in combination with STAT3, and (III) activation of STAT1, 3 and 5. Furthermore, STAT1 and 3 formed stable heterodimers only in cell lines with constitutive STAT3 activation. In all cell lines analyzed, tyrosine phosphorylation of the four known Janus kinases could not be detected, although JAK1 was stably associated with STAT3. To further analyze whether a constitutive activation of tyrosine kinases might contribute to the autonomous growth of AML blasts, inhibitor studies were performed. The tyrphostin AG490, an inhibitor of the JAK-STAT pathway, but not A1, an inactive tyrphostin induced a time- and dose-dependent growth arrest without overt morphological signs of differentiation in AML cell lines. Our results show that STAT transcription factors are constitutively activated in human AML cell lines and might contribute to the autonomous proliferation of AML blasts. Inhibition of this pathway might be of interest for the establishment of more specific antileukemic strategies.
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Röder S, Steimle C, Meinhardt G, Pahl HL. STAT3 is constitutively active in some patients with Polycythemia rubra vera. Exp Hematol 2001; 29:694-702. [PMID: 11378264 DOI: 10.1016/s0301-472x(01)00637-3] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVE Polycythemia vera is a clonal stem cell disorder characterized by hyperproliferation of the erythroid, myeloid, and megakaryocytic lineages. While it has been shown that progenitor cells of P. vera patients are hypersensitive to several growth factors including erythropoietin, insulin-like growth factor-1, thrombopoietin, interleukin-3, and granulocyte/monocyte colony-stimulating factor, the molecular pathogenesis of this disease remains unknown. Growth factor hypersensitivity could be mediated by changes in signal transduction pathways. We therefore investigated a common downstream effector of cytokines, the signal transducers and activators of transcription (STATs). A constitutive activation of STAT factors could explain the increased proliferation of P. vera cells even in the absence of growth factor stimulation. METHODS Peripheral granulocytes from patients with P. vera and from healthy volunteers were assayed for STAT1, 3, and 5 DNA binding by electrophoretic mobility shift assay. RESULTS Four of 14 P. vera patients analyzed showed constitutive STAT3 DNA binding in unstimulated peripheral granulocytes, while none of the 17 healthy volunteers tested did. None of the subjects showed constitutive STAT1 or STAT5 activity. Western blotting demonstrated that, in the three patients, STAT3 is constitutively phosphorylated on Tyr 705, whereas it is unphosphorylated in the other patients and in controls. Interestingly, constitutive STAT3 activity did not correlate with the duration of disease or the treatment regimen. It was observed in a recently diagnosed patient and in two patients treated only with phlebotomy. CONCLUSION Our data suggest that constitutive phosphorylation and activation of STAT3 is not a secondary event induced by mutagenizing agents or by prolonged hyperproliferation of hematopoietic cells, but rather represents a primary molecular aberration. Constitutively active STAT3 may contribute to the growth factor hypersensitivity of P. vera cells.
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Affiliation(s)
- S Röder
- Department of Experimental Anesthesiology, University Hospital Freiburg, Freiburg, Germany
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46
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Affiliation(s)
- R L Ilaria
- Department of Medicine, Division of Hematology/Oncology, Simmons Cancer Center and the Hamon Center for Therapeutic Oncology Research, University of Texas Southwestern Medical Center, Dallas, TX 75390-8593, USA
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Xia Z, Sait SN, Baer MR, Barcos M, Donohue KA, Lawrence D, Ford LA, Block AM, Baumann H, Wetzler M. Truncated STAT proteins are prevalent at relapse of acute myeloid leukemia. Leuk Res 2001; 25:473-82. [PMID: 11337019 DOI: 10.1016/s0145-2126(00)00158-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Signal transducer and activator of transcription (STAT) proteins are implicated in the control of cell survival, proliferation and differentiation in response to hematopoietic cytokines. C-terminally truncated STAT isoforms (STATbeta), as opposed to the full length form (STATalpha), have a competitive or even transdominant negative effect on gene induction mediated by the STAT pathway. We have previously demonstrated that while constitutively active STAT proteins were detected in ten of 36 (28%) for STAT3 and eight of 36 (22%) for STAT5 in pretreatment samples from newly diagnosed acute myeloid leukemia (AML) patients, a significantly larger fraction of samples [21 of 27 (78%)] expressed STATbeta proteins. To determine whether STATbeta expression was maintained or increased after relapse in AML, we compared STAT activity and isoform expression at diagnosis and at relapse in 17 patients. In this selected group, constitutively active STAT3 was detected in 13 of 17 (76%) AML samples at diagnosis but was detected in only four of these patients at relapse. Constitutively active STAT5 was detected in three of 17 (18%) AML samples at diagnosis; but only two at relapse. In contrast, STATbeta protein expression was observed in 12 of the 17 pretreatment samples (71%) and in 16 of 17 samples at relapse. Only one patient did not express STATbeta at relapse. Our results suggest that STATbeta isoform expression, rather than level of constitutive activity, may be involved in disease progression in AML.
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Affiliation(s)
- Z Xia
- Leukemia Section, Department of Medicine, Roswell Park Cancer Institute, Elm and Carlton Streets, Buffalo, NY 14263, USA
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Abstract
Myeloid differentiation is a highly regulated process governed by various cytokines, such as EPO, TPO, G-CSF, IL-3, IL-5 and GM-CSF. These cytokines act in part through activation of the STAT transcription factor family. In particular, various isoforms of STAT3 and STAT5 are activated during myeloid differentiation in a cell-type and maturation-state dependent fashion. In vitro studies have shown that STAT proteins are essential for cytokine-regulated processes such as cellular proliferation, differentiation as well as survival. Similarly, various STAT knock-outs have highlighted the role of STATs in myeloid differentiation in vivo. STATs also appear to play an important role in various myeloid malignancies, which are characterized by arrested maturation and cytokine-independent proliferation of myeloid progenitors. Constitutive activation of STAT3 and/or STAT5 resulting in enhanced transcription of anti-apoptotic- cell-cycle progression genes is likely to contribute to the pathogenesis of various myeloid leukemia's. Oncogene (2000).
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Affiliation(s)
- P J Coffer
- Department of Pulmonary Diseases, Room G03 550, University Medical Center Utrecht, Heidelberglaan 100, 3584CX Utrecht, The Netherlands
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49
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Schaefer LK, Menter DG, Schaefer TS. Activation of stat3 and stat1 DNA binding and transcriptional activity in human brain tumour cell lines by gp130 cytokines. Cell Signal 2000; 12:143-51. [PMID: 10704821 DOI: 10.1016/s0898-6568(99)00077-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In this study we examine the activation of the latent Stat family of transcription factors by the gp130 family of cytokines in cell lines derived from human brain tumours. Of the cytokines tested, oncostatin M resulted in the most dramatic induction of Stat1 and Stat3 in all cell lines analysed, as assessed by the formation of protein/DNA complexes. Interleukin-6, leukemia inhibitory factor, and ciliary neurotrophic factor also induced Stat complexes more selectively and to a lesser magnitude than oncostatin M. The kinetics of Stat1 and Stat3 activation was rapid and transient; the nuclear accumulation of DNA binding-proficient Stat protein was detected in the nucleus within minutes of cytokine induction. The transcriptional potential of the oncostatin M-activated Stat molecules was demonstrated in two glioma cell lines (U87-MG, SNB-19) by transient transfection experiments using a Stat-responsive reporter plasmid. Oncostatin M-dependent transcription from this reporter plasmid was reduced to uninduced levels by the inclusion of a dominant-negative Stat3 molecule, demonstrating that Stat molecules were responsible for the induction. These studies demonstrate that oncostatin M is the most potent activator of Stat molecules in a variety of brain tumour-derived cell lines, an observation that could have implications affecting the balance between proliferation/apoptosis of these cells.
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Affiliation(s)
- L K Schaefer
- Department of Neurosurgery, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
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Touw IP, De Koning JP, Ward AC, Hermans MH. Signaling mechanisms of cytokine receptors and their perturbances in disease. Mol Cell Endocrinol 2000; 160:1-9. [PMID: 10715533 DOI: 10.1016/s0303-7207(99)00206-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cytokines regulate the proliferation and differentiation of cells through their interaction with specific receptors on the surface of target cells which are coupled to intracellular signal transduction pathways. The cytokine receptor class I superfamily, characterized by structural homology in the extracellular domain, includes receptors for many interleukins and hematopoietic growth factors, but also those of growth hormone, leptin, ciliary neurotrophic factor (CNTF), oncostatin M (OSM), leukemia inhibitory factor (LIF) and cardiotrophin-1 (CT-1). The receptors for interferons are structurally distinct and have therefore been categorized separately (class II cytokine receptors). The discovery of the JAK/STAT pathway in the early 1990s has been an important step forward in deciphering cytokine mediated signaling. This pathway connects activation of the receptor complexes directly to transcription of genes. Studies of humans and mice, deficient for one of the JAKs or STATs, have revealed crucial roles of these molecules in embryonic development, blood cell formation and immune responses. In addition, recent studies have revealed some of the mechanisms that control the activation of the JAKs and STATs, which contribute to signal intensity and specificity. In this review we will summarize these recent insights and discuss their implications for a variety of pathological conditions.
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Affiliation(s)
- I P Touw
- Institute of Hematology, Erasmus University Rotterdam (Room 1314), PO Box 1738, 3000DR, Rotterdam, The Netherlands.
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