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Zhao Y, Peng H. The Role of N 6-Methyladenosine (m 6A) Methylation Modifications in Hematological Malignancies. Cancers (Basel) 2022; 14:cancers14020332. [PMID: 35053496 PMCID: PMC8774242 DOI: 10.3390/cancers14020332] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/25/2021] [Accepted: 01/05/2022] [Indexed: 12/30/2022] Open
Abstract
Simple Summary Recently, despite the common application of various novel therapies (e.g., immunotherapy and stem cell transplantation) in hematologic tumors, hematologic malignancies remain suboptimal and have a worse prognosis due to the lack of donors and their high heterogeneity. Among them, epigenetic alterations (e.g., the abnormal modification of m6A) are essential to facilitate the progression of tumors and drug resistance. Our purpose in this study is to pinpoint the molecular targets of pathogenesis, as well as to analyze the oncogenic characteristics of m6A modifications. In this article, we, therefore, elaborate on the mechanisms of m6A modification and its role in normal hematopoietic regulation and malignant tumorigenesis, thus contributing to the refinement of molecularly targeted therapies. Abstract Epigenetics is identified as the study of heritable modifications in gene expression and regulation that do not involve DNA sequence alterations, such as DNA methylation, histone modifications, etc. Importantly, N6-methyladenosine (m6A) methylation modification is one of the most common epigenetic modifications of eukaryotic messenger RNA (mRNA), which plays a key role in various cellular processes. It can not only mediate various RNA metabolic processes such as RNA splicing, translation, and decay under the catalytic regulation of related enzymes but can also affect the normal development of bone marrow hematopoiesis by regulating the self-renewal, proliferation, and differentiation of pluripotent stem cells in the hematopoietic microenvironment of bone marrow. In recent years, numerous studies have demonstrated that m6A methylation modifications play an important role in the development and progression of hematologic malignancies (e.g., leukemia, lymphoma, myelodysplastic syndromes [MDS], multiple myeloma [MM], etc.). Targeting the inhibition of m6A-associated factors can contribute to increased susceptibility of patients with hematologic malignancies to therapeutic agents. Therefore, this review elaborates on the biological characteristics and normal hematopoietic regulatory functions of m6A methylation modifications and their role in the pathogenesis of hematologic malignancies.
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Affiliation(s)
- Yan Zhao
- Hunan Province Key Laboratory of Basic and Applied Hematology, Department of Hematology, The Second Xiangya Hospital, Central South University, Changsha 410011, China;
- Institute of Hematology, Central South University, Changsha 410011, China
| | - Hongling Peng
- Hunan Province Key Laboratory of Basic and Applied Hematology, Department of Hematology, The Second Xiangya Hospital, Central South University, Changsha 410011, China;
- Institute of Hematology, Central South University, Changsha 410011, China
- Hunan Key Laboratory of Tumor Models and Individualized Medicine, Changsha 410011, China
- Correspondence: ; Tel.: +86-731-85295296
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2
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Ianniello Z, Sorci M, Ceci Ginistrelli L, Iaiza A, Marchioni M, Tito C, Capuano E, Masciarelli S, Ottone T, Attrotto C, Rizzo M, Franceschini L, de Pretis S, Voso MT, Pelizzola M, Fazi F, Fatica A. New insight into the catalytic -dependent and -independent roles of METTL3 in sustaining aberrant translation in chronic myeloid leukemia. Cell Death Dis 2021; 12:870. [PMID: 34561421 PMCID: PMC8463696 DOI: 10.1038/s41419-021-04169-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 09/03/2021] [Accepted: 09/16/2021] [Indexed: 12/13/2022]
Abstract
Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm caused by the presence of tyrosine kinase BCR-ABL1 fusion protein, which deregulate transcription and mRNA translation. Tyrosine kinase inhibitors (TKIs) are the first-choice treatment. However, resistance to TKIs remains a challenge to cure CML patients. Here, we reveal that the m6A methyltransferase complex METTL3/METTL14 is upregulated in CML patients and that is required for proliferation of primary CML cells and CML cell lines sensitive and resistant to the TKI imatinib. We demonstrate that depletion of METTL3 strongly impairs global translation efficiency. In particular, our data show that METTL3 is crucial for the expression of genes involved in ribosome biogenesis and translation. Specifically, we found that METTL3 directly regulates the level of PES1 protein identified as an oncogene in several tumors. We propose a model in which nuclear METTL3/METTL14 methyltransferase complex modified nascent transcripts whose translation is enhanced by cytoplasmic localization of METTL3, independently from its catalytic activity. In conclusion, our results point to METTL3 as a novel relevant oncogene in CML and as a promising therapeutic target for TKI resistant CML.
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Affiliation(s)
- Zaira Ianniello
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Melissa Sorci
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Lavinia Ceci Ginistrelli
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, Rome, Italy
| | - Alessia Iaiza
- Department of Anatomical, Histological, Forensic & Orthopedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Marcella Marchioni
- Institute of Biology, Molecular Medicine and Nanobiotechnology, CNR, Sapienza University of Rome, Rome, Italy
| | - Claudia Tito
- Department of Anatomical, Histological, Forensic & Orthopedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Ernestina Capuano
- Department of Anatomical, Histological, Forensic & Orthopedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Silvia Masciarelli
- Department of Anatomical, Histological, Forensic & Orthopedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Rome, Italy.,Histology and Embryology Section, Department of Life Science and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Tiziana Ottone
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.,Fondazione Santa Lucia, Laboratorio di Neuro-Oncoematologia, Rome, Italy
| | - Cristina Attrotto
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | | | | | - Stefano de Pretis
- Center for Genomic Science, Fondazione Istituto Italiano di Tecnologia, Milan, Italy
| | - Maria Teresa Voso
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.,Fondazione Santa Lucia, Laboratorio di Neuro-Oncoematologia, Rome, Italy
| | - Mattia Pelizzola
- Center for Genomic Science, Fondazione Istituto Italiano di Tecnologia, Milan, Italy
| | - Francesco Fazi
- Department of Anatomical, Histological, Forensic & Orthopedic Sciences, Section of Histology & Medical Embryology, Sapienza University of Rome, Rome, Italy. .,Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Rome, Italy.
| | - Alessandro Fatica
- Department of Biology and Biotechnology 'Charles Darwin', Sapienza University of Rome, Rome, Italy.
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3
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Mechanisms of Disease Progression and Resistance to Tyrosine Kinase Inhibitor Therapy in Chronic Myeloid Leukemia: An Update. Int J Mol Sci 2019; 20:ijms20246141. [PMID: 31817512 PMCID: PMC6940932 DOI: 10.3390/ijms20246141] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 11/29/2019] [Accepted: 12/04/2019] [Indexed: 12/24/2022] Open
Abstract
Chronic myeloid leukemia (CML) is characterized by the presence of the BCR-ABL1 fusion gene, which encodes a constitutive active tyrosine kinase considered to be the pathogenic driver capable of initiating and maintaining the disease. Despite the remarkable efficacy of tyrosine kinase inhibitors (TKIs) targeting BCR-ABL1, some patients may not respond (primary resistance) or may relapse after an initial response (secondary resistance). In a small proportion of cases, development of resistance is accompanied or shortly followed by progression from chronic to blastic phase (BP), characterized by a dismal prognosis. Evolution from CP into BP is a multifactorial and probably multistep phenomenon. Increase in BCR-ABL1 transcript levels is thought to promote the onset of secondary chromosomal or genetic defects, induce differentiation arrest, perturb RNA transcription, editing and translation that together with epigenetic and metabolic changes may ultimately lead to the expansion of highly proliferating, differentiation-arrested malignant cells. A multitude of studies over the past two decades have investigated the mechanisms underlying the closely intertwined phenomena of drug resistance and disease progression. Here, we provide an update on what is currently known on the mechanisms underlying progression and present the latest acquisitions on BCR-ABL1-independent resistance and leukemia stem cell persistence.
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Tsai BP, Jimenez J, Lim S, Fitzgerald KD, Zhang M, Chuah CTH, Axelrod H, Wilson L, Ong ST, Semler BL, Waterman ML. A novel Bcr-Abl-mTOR-eIF4A axis regulates IRES-mediated translation of LEF-1. Open Biol 2015; 4:140180. [PMID: 25392452 PMCID: PMC4248067 DOI: 10.1098/rsob.140180] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Internal ribosome entry sites (IRESs) in cellular mRNAs direct expression of growth-promoting factors through an alternative translation mechanism that has yet to be fully defined. Lymphoid enhancer factor-1 (LEF-1), a Wnt-mediating transcription factor important for cell survival and metastasis in cancer, is produced via IRES-directed translation, and its mRNA is frequently upregulated in malignancies, including chronic myeloid leukaemia (CML). In this study, we determined that LEF1 expression is regulated by Bcr-Abl, the oncogenic protein that drives haematopoietic cell transformation to CML. We have previously shown that the LEF1 5′ untranslated region recruits a complex of proteins to its IRES, including the translation initiation factor eIF4A. In this report, we use two small molecule inhibitors, PP242 (dual mTOR (mammalian target of rapamycin) kinase inhibitor) and hippuristanol (eIF4A inhibitor), to define IRES regulation via a Bcr-Abl–mTOR–eIF4A axis in CML cell lines and primary patient leukaemias. We found that LEF1 and other IRESs are uniquely sensitive to the activities of Bcr-Abl/mTOR. Most notably, we discovered that eIF4A, an RNA helicase, elicits potent non-canonical effects on the LEF1 IRES. Hippuristanol inhibition of eIF4A stalls translation of IRES mRNA and triggers dissociation from polyribosomes. We propose that a combination drug strategy which targets mTOR and IRES-driven translation disrupts key factors that contribute to growth and proliferation in CML.
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Affiliation(s)
- Becky Pinjou Tsai
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Judith Jimenez
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Sharon Lim
- Cancer and Stem Cell Biology Signature Research Program, Duke-NUS Graduate Medical School, Singapore Department of Haematology, Singapore General Hospital, Singapore
| | - Kerry D Fitzgerald
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Min Zhang
- Division of Hematology/Oncology, Department of Medicine, School of Medicine, University of California, Irvine, CA, USA
| | - Charles T H Chuah
- Cancer and Stem Cell Biology Signature Research Program, Duke-NUS Graduate Medical School, Singapore Department of Haematology, Singapore General Hospital, Singapore
| | - Haley Axelrod
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Luke Wilson
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - S Tiong Ong
- Cancer and Stem Cell Biology Signature Research Program, Duke-NUS Graduate Medical School, Singapore Department of Haematology, Singapore General Hospital, Singapore Department of Medical Oncology, National Cancer Centre, Singapore Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Bert L Semler
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Marian L Waterman
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
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Borgo C, Franchin C, Salizzato V, Cesaro L, Arrigoni G, Matricardi L, Pinna LA, Donella-Deana A. Protein kinase CK2 potentiates translation efficiency by phosphorylating eIF3j at Ser127. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1693-701. [PMID: 25887626 DOI: 10.1016/j.bbamcr.2015.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 03/17/2015] [Accepted: 04/07/2015] [Indexed: 11/18/2022]
Abstract
In eukaryotic protein synthesis the translation initiation factor 3 (eIF3) is a key player in the recruitment and assembly of the translation initiation machinery. Mammalian eIF3 consists of 13 subunits, including the loosely associated eIF3j subunit that plays a stabilizing role in the eIF3 complex formation and interaction with the 40S ribosomal subunit. By means of both co-immunoprecipitation and mass spectrometry analyses we demonstrate that the protein kinase CK2 interacts with and phosphorylates eIF3j at Ser127. Inhibition of CK2 activity by CX-4945 or down-regulation of the expression of CK2 catalytic subunit by siRNA cause the dissociation of j-subunit from the eIF3 complex as judged from glycerol gradient sedimentation. This finding proves that CK2-phosphorylation of eIF3j is a prerequisite for its association with the eIF3 complex. Expression of Ser127Ala-eIF3j mutant impairs both the interaction of mutated j-subunit with the other eIF3 subunits and the overall protein synthesis. Taken together our data demonstrate that CK2-phosphorylation of eIF3j at Ser127 promotes the assembly of the eIF3 complex, a crucial step in the activation of the translation initiation machinery.
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Affiliation(s)
- Christian Borgo
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy; CNR Institute of NeuroSciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy
| | - Cinzia Franchin
- Proteomic Center of Padova University, Via G. Orus B2, 35129 Padova, Italy
| | - Valentina Salizzato
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy; CNR Institute of NeuroSciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy
| | - Luca Cesaro
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy; CNR Institute of NeuroSciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy
| | - Giorgio Arrigoni
- Proteomic Center of Padova University, Via G. Orus B2, 35129 Padova, Italy
| | - Laura Matricardi
- Venitian Institute of Oncology (IOV-IRCCS), Via Gattamelata 64, 35128 Padova, Italy
| | - Lorenzo A Pinna
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy; CNR Institute of NeuroSciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy
| | - Arianna Donella-Deana
- Department of Biomedical Sciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy; CNR Institute of NeuroSciences, University of Padova, Via U. Bassi 58B, 35131 Padova, Italy.
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The role of translation initiation regulation in haematopoiesis. Comp Funct Genomics 2012; 2012:576540. [PMID: 22649283 PMCID: PMC3357504 DOI: 10.1155/2012/576540] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 02/25/2012] [Indexed: 02/06/2023] Open
Abstract
Organisation of RNAs into functional subgroups that are translated in response to extrinsic and intrinsic factors underlines a relatively unexplored gene expression modulation that drives cell fate in the same manner as regulation of the transcriptome by transcription factors. Recent studies on the molecular mechanisms of inflammatory responses and haematological disorders indicate clearly that the regulation of mRNA translation at the level of translation initiation, mRNA stability, and protein isoform synthesis is implicated in the tight regulation of gene expression. This paper outlines how these posttranscriptional control mechanisms, including control at the level of translation initiation factors and the role of RNA binding proteins, affect hematopoiesis. The clinical relevance of these mechanisms in haematological disorders indicates clearly the potential therapeutic implications and the need of molecular tools that allow measurement at the level of translational control. Although the importance of miRNAs in translation control is well recognised and studied extensively, this paper will exclude detailed account of this level of control.
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7
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Tschiedel S, Bach E, Jilo A, Wang SY, Lange T, Al-Ali HK, Vucinic V, Niederwieser D, Cross M. Bcr–Abl dependent post-transcriptional activation of NME2 expression is a specific and common feature of chronic myeloid leukemia. Leuk Lymphoma 2012; 53:1569-76. [DOI: 10.3109/10428194.2012.656631] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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8
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Perrotti D, Harb JG. BCR-ABL1 kinase-dependent alteration of mRNA metabolism: potential alternatives for therapeutic intervention. Leuk Lymphoma 2011; 52 Suppl 1:30-44. [PMID: 21299458 DOI: 10.3109/10428194.2010.546914] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The use of first- and second-generation tyrosine kinase inhibitors (TKIs) significantly improves prognosis for patients with early chronic phase chronic myeloid leukemia (CML) and efficiently counteracts leukemia in most patients with CML bearing a disease characterized by the expression of BCR-ABL1 mutants. However, the so-called 'tinib' TKIs (e.g. imatinib, nilotinib, dasatinib, and bosutinib) are both ineffective in patients who undergo blastic transformation and unable to eradicate CML at the stem cell level. This raises a few important questions. Is BCR-ABL1 expression and/or activity essential for blastic transformation? Is blastic transformation the result of genetic or epigenetic events that occur at the stem cell level which only become apparent in the granulocyte-macrophage progenitor (GMP) cell pool, or does it arise directly at the GMP level? As altered mRNA metabolism contributes to the phenotype of blast crisis CML progenitors (decreased translation of tumor suppressor genes and transcription factors essential for terminal differentiation and increased translation of anti-apoptotic genes), one attractive concept is to restore levels of these essential molecules to their normal levels. In this review, we discuss the mechanisms by which mRNA processing, translation, and degradation are deregulated in BCR-ABL1 myeloid blast crisis CML progenitors, and present encouraging results from studies with pharmacologic inhibitors which support their inclusion in the clinic.
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Affiliation(s)
- Danilo Perrotti
- Human Cancer Genetics Program, Depatment of Molecular Virology, Immunology and Medical Genetics, Comprehensive Cancer Center and Center for RNA Biology, The Ohio State University, Columbus, OH 43210-2207, USA.
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Role of BCR-ABL-Y177-mediated p27kip1 phosphorylation and cytoplasmic localization in enhanced proliferation of chronic myeloid leukemia progenitors. Leukemia 2010; 24:779-87. [PMID: 20200561 PMCID: PMC2854856 DOI: 10.1038/leu.2010.24] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In chronic myelogenous leukemia (CML) hematopoietic stem cell transformation leads to increased proliferation of malignant myeloid progenitors. The cyclin-dependent kinase inhibitor p27kip1 (p27) is a critical negative regulator of hematopoietic progenitor proliferation and pool size that is deregulated in BCR-ABL expressing cell lines. However, cell-context specific regulation of p27 in primary human CML progenitors and its contribution to CML progenitor expansion remain unclear. Here we investigated p27 regulation and function in (1) CD34+ cells from CML patients and (2) human CD34+ cells ectopically expressing the BCR-ABL gene following retrovirus transduction. We found that p27 levels are increased in CML CD34+ cells related to a BCR-ABL dependent increase in p27 protein translation. However p27 was relocated to the cytoplasm in CML progenitors and nuclear p27 levels were reduced, allowing increased cell cycling and expansion in culture. Cytoplasmic relocation of p27 in CML progenitors was related to signaling through BCR-ABL Y177, activation of the AKT kinase and phosphorylation of p27 on Thr-157 (T157). Expression of a mutant p27 that cannot be phosphorylated on T157 significant inhibited CML progenitor proliferation. These studies demonstrate the importance of BCR-ABL-Y177-AKT mediated p27 phosphorylation in altered p27 localization and enhanced proliferation and expansion of primary CML progenitors.
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Inhibition of polysome assembly enhances imatinib activity against chronic myelogenous leukemia and overcomes imatinib resistance. Mol Cell Biol 2008; 28:6496-509. [PMID: 18694961 DOI: 10.1128/mcb.00477-08] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dysregulated mRNA translation is implicated in the pathogenesis of many human cancers including chronic myelogenous leukemia (CML). Because our prior work has specifically implicated translation initiation in CML, we tested compounds that could modulate translation initiation and polysomal mRNA assembly. Here, we evaluated the activity of one such compound, CGP57380, against CML cells and explored its mechanisms of action. First, using polysomal mRNA profiles, we found that imatinib and CGP57380 could independently, and cooperatively, impair polysomal mRNA loading. Imatinib and CGP57380 also synergistically inhibited the growth of Ba/F3-Bcr-Abl and K562 cells via impaired cell cycle entry and increased apoptosis. Mechanistically, CGP57380 inhibited efficient polysomal assembly via two processes. First, it enhanced imatinib-mediated inhibition of eukaryotic initiation factor 4F induction, and second, it independently impaired phosphorylation of ribosomal protein S6 on the preinitiation complex. We also identified multiple substrates of the mTOR, Rsk, and Mnk kinases as targets of CGP57380. Finally, we found a novel negative-feedback loop to the mitogen-activated protein kinase/Mnk pathway that is triggered by CGP57380 and demonstrated that an interruption of the loop further increased the activity of the combination against imatinib-sensitive and -resistant CML cells. Together, this work supports the inhibition of translation initiation as a therapeutic strategy for treating cancers fueled by dysregulated translation.
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Chang JS, Santhanam R, Trotta R, Neviani P, Eiring AM, Briercheck E, Ronchetti M, Roy DC, Calabretta B, Caligiuri MA, Perrotti D. High levels of the BCR/ABL oncoprotein are required for the MAPK-hnRNP-E2 dependent suppression of C/EBPalpha-driven myeloid differentiation. Blood 2007; 110:994-1003. [PMID: 17475908 PMCID: PMC1924762 DOI: 10.1182/blood-2007-03-078303] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Accepted: 04/24/2007] [Indexed: 12/21/2022] Open
Abstract
The inability of myeloid chronic myelogenous leukemia blast crisis (CML-BC) progenitors to undergo neutrophil differentiation depends on suppression of C/EBPalpha expression through the translation inhibitory activity of the RNA-binding protein hnRNP-E2. Here we show that "oncogene dosage" is a determinant factor for suppression of differentiation in CML-BC. In fact, high levels of p210-BCR/ABL are required for enhanced hnRNP-E2 expression, which depends on phosphorylation of hnRNP-E2 serines 173, 189, and 272 and threonine 213 by the BCR/ABL-activated MAPK(ERK1/2). Serine/threonine to alanine substitution abolishes hnRNP-E2 phosphorylation and markedly decreases its stability in BCR/ABL-expressing myeloid precursors. Similarly, pharmacologic inhibition of MAPK(ERK1/2) activity decreases hnRNP-E2 binding to the 5'UTR of C/EBPalpha mRNA by impairing hnRNP-E2 phosphorylation and stability. This, in turn, restores in vitro and/or in vivo C/EBPalpha expression and G-CSF-driven neutrophilic maturation of differentiation-arrested BCR/ABL(+) cell lines, primary CML-BC(CD34+) patient cells and lineage-negative mouse bone marrow cells expressing high levels of p210-BCR/ABL. Thus, increased BCR/ABL oncogenic tyrosine kinase activity is essential for suppression of myeloid differentiation of CML-BC progenitors as it is required for sustained activation of the MAPK(ERK1/2)-hnRNP-E2-C/EBPalpha differentiation-inhibitory pathway. Furthermore, these findings suggest the inclusion of clinically relevant MAPK inhibitors in the therapy of CML-BC.
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MESH Headings
- Animals
- Blast Crisis/drug therapy
- Blast Crisis/metabolism
- Blast Crisis/pathology
- CCAAT-Enhancer-Binding Protein-alpha/biosynthesis
- Cell Differentiation/drug effects
- Enzyme Inhibitors/pharmacology
- Enzyme Inhibitors/therapeutic use
- Fusion Proteins, bcr-abl/biosynthesis
- Gene Expression Regulation, Leukemic/drug effects
- Heterogeneous-Nuclear Ribonucleoproteins/metabolism
- Humans
- K562 Cells
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Mice
- Mitogen-Activated Protein Kinase 1/antagonists & inhibitors
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/antagonists & inhibitors
- Mitogen-Activated Protein Kinase 3/metabolism
- Myeloid Progenitor Cells/metabolism
- Myeloid Progenitor Cells/pathology
- Neutrophils/metabolism
- Neutrophils/pathology
- Phosphorylation/drug effects
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Affiliation(s)
- Ji Suk Chang
- Human Cancer Genetics Program, Department of Molecular Virology, Immunology and Medical Genetics, Ohio State University, Columbus, OH 23240, USA
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12
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Perrotti D, Neviani P. From mRNA metabolism to cancer therapy: chronic myelogenous leukemia shows the way. Clin Cancer Res 2007; 13:1638-42. [PMID: 17363515 DOI: 10.1158/1078-0432.ccr-06-2320] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Altered mRNA metabolism is a feature of many cancers including blast crisis chronic myelogenous leukemia. Indeed, loss of function of many tumor suppressors regulating cell proliferation, survival, and differentiation results from aberrant mRNA processing, nuclear export, and/or translation. Here, we summarize the effects of increased BCR/ABL oncogenic activity on the expression and function of RNA binding proteins (e.g., FUS, hnRNP A1, hnRNP E2, hnRNP K, and La/SSB) with posttranscriptional and translational regulatory activities and their importance for the phenotype of BCR/ABL-transformed hematopoietic progenitors. We also provide evidence that these studies not only advance our understanding on the molecular mechanisms contributing to tumor/leukemia emergence, maintenance, and/or progression but they also serve for the identification of novel molecular targets useful for the development of alternative therapies for imatinib-resistant and blast crisis chronic myelogenous leukemia and, perhaps, for other cancers characterized by similar alterations in the mRNA metabolism.
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MESH Headings
- Animals
- Autoantigens/physiology
- CCAAT-Enhancer-Binding Proteins/physiology
- CELF1 Protein
- Chromosomal Proteins, Non-Histone/physiology
- DNA-Binding Proteins
- Heterogeneous-Nuclear Ribonucleoprotein K
- Heterogeneous-Nuclear Ribonucleoproteins/physiology
- Histone Chaperones
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/therapy
- Models, Biological
- Neoplasms/metabolism
- Neoplasms/therapy
- Peptide Fragments/physiology
- Phosphoprotein Phosphatases/physiology
- Proto-Oncogene Proteins c-mdm2/physiology
- RNA, Messenger/metabolism
- RNA-Binding Proteins/metabolism
- RNA-Binding Proteins/physiology
- Receptors, Granulocyte Colony-Stimulating Factor/physiology
- Ribonucleoproteins/physiology
- Signal Transduction
- Transcription Factors/physiology
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Affiliation(s)
- Danilo Perrotti
- The Molecular Biology and Cancer Genetics Program, Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43240, USA.
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Sayan AE, Roperch JP, Sayan BS, Rossi M, Pinkoski MJ, Knight RA, Willis AE, Melino G. Generation of DeltaTAp73 proteins by translation from a putative internal ribosome entry site. Ann N Y Acad Sci 2007; 1095:315-24. [PMID: 17404044 DOI: 10.1196/annals.1397.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
p73 belongs to a family of transcription factors, including p53 and p63, that mediate response to DNA damage and cellular stress by inducing DNA repair, cell cycle arrest, and apoptosis. TP73 gene contains two promotors and several splice variants resulting in up to 24 possible permutations of p73 proteins which underlies the complexity of the family and its regulatory mechanisms. p73 variants lacking the N-terminal, denoted as DeltaTAp73, are not transcriptionally competent and they act in a dominant negative fashion over TAp73. DeltaTAp73 isoforms can be generated by alternative promotor usage, giving rise to DeltaNp73, or alternative splicing of exons 2, 3 or 2, and 3 together. Such transcript isoforms potentially produce oncogenic proteins and they were shown to be present in primary tumors and tumor-derived cell lines. We investigated the possibility of additional mechanisms by which p73 protein could be regulated and discovered a putative internal ribosome entry site (IRES) in exon 2. Translation initiation of TAp73 mRNA results in a DeltaNp73-like peptide, thus demonstrating an additional mechanism whereby a DeltaTA p73 protein is produced from a transcript originally generated from the P1 promotor of the p73 gene.
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Affiliation(s)
- A Emre Sayan
- Medical Research Council Toxicology Unit, Hodgkin Building, Lancaster Road, University of Leicester, Leicester, LE1 9HN United Kingdom
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14
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Prabhu S, Saadat D, Zhang M, Halbur L, Fruehauf JP, Ong ST. A novel mechanism for Bcr-Abl action: Bcr-Abl-mediated induction of the eIF4F translation initiation complex and mRNA translation. Oncogene 2007; 26:1188-200. [PMID: 16936779 PMCID: PMC2527622 DOI: 10.1038/sj.onc.1209901] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2006] [Revised: 06/26/2006] [Accepted: 07/11/2006] [Indexed: 12/30/2022]
Abstract
The oncogenic kinase Bcr-Abl is thought to cause chronic myelogenous leukemia (CML) by altering the transcription of specific genes with growth- and survival-promoting functions. Recently, Bcr-Abl has also been shown to activate an important regulator of protein synthesis, the mammalian target of rapamycin (mTOR), which suggests that dysregulated translation may also contribute to CML pathogenesis. In this study, we found that both Bcr-Abl and the rapamycin-sensitive mTORC1 complex contribute to the phosphorylation (inactivation) of 4E-BP1, an inhibitor of the eIF4E translation initiation factor. Experiments with rapamycin and the Bcr-Abl inhibitor, imatinib mesylate, in Bcr-Abl-expressing cell lines and primary CML cells indicated that Bcr-Abl and mTORC1 induced formation of the translation initiation complex, eIF4F. This was characterized by reduced 4E-BP1 binding and increased eIF4G binding to eIF4E, two events that lead to the assembly of eIF4F. One target transcript is cyclin D3, which is regulated in Bcr-Abl-expressing cells by both Bcr-Abl and mTORC1 in a translational manner. In addition, the combination of imatinib and rapamycin was found to act synergistically against committed CML progenitors from chronic and blast phase patients. These experiments establish a novel mechanism of action for Bcr-Abl, and they provide insights into the modes of action of imatinib mesylate and rapamycin in treatment of CML. They also suggest that aberrant cap-dependent mRNA translation may be a therapeutic target in Bcr-Abl-driven malignancies.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Animals
- Antibiotics, Antineoplastic
- Benzamides
- Carrier Proteins/metabolism
- Cell Cycle Proteins
- Cyclin D3
- Cyclins/metabolism
- Eukaryotic Initiation Factor-4F/metabolism
- Eukaryotic Initiation Factor-4G/metabolism
- Eukaryotic Initiation Factors
- Fusion Proteins, bcr-abl/antagonists & inhibitors
- Fusion Proteins, bcr-abl/physiology
- Humans
- Imatinib Mesylate
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Mechanistic Target of Rapamycin Complex 1
- Mice
- Multiprotein Complexes
- Phosphoproteins/metabolism
- Phosphorylation
- Piperazines/pharmacology
- Protein Biosynthesis/drug effects
- Proteins
- Pyrimidines/pharmacology
- Sirolimus/pharmacology
- TOR Serine-Threonine Kinases
- Transcription Factors/antagonists & inhibitors
- Transcription Factors/metabolism
- Tumor Cells, Cultured
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Affiliation(s)
- S Prabhu
- The Division of Hematology/Oncology, University of California, Irvine, CA 92697, USA
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15
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Perrotti D, Neviani P. ReSETting PP2A tumour suppressor activity in blast crisis and imatinib-resistant chronic myelogenous leukaemia. Br J Cancer 2006; 95:775-81. [PMID: 16953242 PMCID: PMC2360538 DOI: 10.1038/sj.bjc.6603317] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The deregulated kinase activity of p210-BCR/ABL oncoproteins, hallmark of chronic myelogenous leukaemia (CML), induces and sustains the leukaemic phenotype, and contributes to disease progression. Imatinib mesylate, a BCR/ABL kinase inhibitor, is effective in most of chronic phase CML patients. However, a significant percentage of CML patients develop resistance to imatinib and/or still progresses to blast crisis, a disease stage that is often refractory to imatinib therapy. Furthermore, there is compelling evidence indicating that the CML leukaemia stem cell is also resistant to imatinib. Thus, there is still a need for new drugs that, if combined with imatinib, will decrease the rate of relapse, fully overcome imatinib resistance and prevent blastic transformation of CML. We recently reported that the activity of the tumour suppressor protein phosphatase 2A (PP2A) is markedly inhibited in blast crisis CML patient cells and that molecular or pharmacologic re-activation of PP2A phosphatase led to growth suppression, enhanced apoptosis, impaired clonogenic potential and decreased in vivo leukaemogenesis of imatinib-sensitive and -resistant (T315I included) CML-BC patient cells and/or BCR/ABL+ myeloid progenitor cell lines. Thus, the combination of PP2A phosphatase-activating and BCR/ABL kinase-inhibiting drugs may represent a powerful therapeutic strategy for blast crisis CML patients.
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Affiliation(s)
- D Perrotti
- Human Cancer Genetics Program, Department of Molecular Virology, Immunology and Medical Genetics, and The Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA.
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Notari M, Neviani P, Santhanam R, Blaser BW, Chang JS, Galietta A, Willis AE, Roy DC, Caligiuri MA, Marcucci G, Perrotti D. A MAPK/HNRPK pathway controls BCR/ABL oncogenic potential by regulating MYC mRNA translation. Blood 2006; 107:2507-16. [PMID: 16293596 PMCID: PMC1895740 DOI: 10.1182/blood-2005-09-3732] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Altered mRNA translation is one of the effects exerted by the BCR/ABL oncoprotein in the blast crisis phase of chronic myelogenous leukemia (CML). Here, we report that in BCR/ABL+ cell lines and in patient-derived CML blast crisis mononuclear and CD34+ cells, p210(BCR/ABL) increases expression and activity of the transcriptional-inducer and translational-regulator heterogeneous nuclear ribonucleoprotein K (hnRNP K or HNRPK) in a dose- and kinase-dependent manner through the activation of the MAPK(ERK1/2) pathway. Furthermore, HNRPK down-regulation and interference with HNRPK translation-but not transcription-regulatory activity impairs cytokine-independent proliferation, clonogenic potential, and in vivo leukemogenic activity of BCR/ABL-expressing myeloid 32Dcl3 and/or primary CD34+ CML-BC patient cells. Mechanistically, we demonstrate that decreased internal ribosome entry site (IRES)-dependent Myc mRNA translation accounts for the phenotypic changes induced by inhibition of the BCR/ABL-ERK-dependent HNRPK translation-regulatory function. Accordingly, MYC protein but not mRNA levels are increased in the CD34+ fraction of patients with CML in accelerated and blastic phase but not in chronic phase CML patients and in the CD34+ fraction of marrow cells from healthy donors. Thus, BCR/ABL-dependent enhancement of HNRPK translation-regulation is important for BCR/ABL leukemogenesis and, perhaps, it might contribute to blast crisis transformation.
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Affiliation(s)
- Mario Notari
- Human Cancer Genetics Program, The Ohio State University Medical Center, Columbus, OH 43240, USA
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