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Shestakova ED, Smirnova VV, Shatsky IN, Terenin IM. Specific mechanisms of translation initiation in higher eukaryotes: the eIF4G2 story. RNA (NEW YORK, N.Y.) 2023; 29:282-299. [PMID: 36517212 PMCID: PMC9945437 DOI: 10.1261/rna.079462.122] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The eukaryotic initiation factor 4G2 (eIF4G2, DAP5, Nat1, p97) was discovered in 1997. Over the past two decades, dozens of papers have presented contradictory data on eIF4G2 function. Since its identification, eIF4G2 has been assumed to participate in noncanonical translation initiation mechanisms, but recent results indicate that it can be involved in scanning as well. In particular, eIF4G2 provides leaky scanning through some upstream open reading frames (uORFs), which are typical for long 5' UTRs of mRNAs from higher eukaryotes. It is likely the protein can also help the ribosome overcome other impediments during scanning of the 5' UTRs of animal mRNAs. This may explain the need for eIF4G2 in higher eukaryotes, as many mRNAs that encode regulatory proteins have rather long and highly structured 5' UTRs. Additionally, they often bind to various proteins, which also hamper the movement of scanning ribosomes. This review discusses the suggested mechanisms of eIF4G2 action, denotes obscure or inconsistent results, and proposes ways to uncover other fundamental mechanisms in which this important protein factor may be involved in higher eukaryotes.
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Affiliation(s)
- Ekaterina D Shestakova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Victoria V Smirnova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Ivan N Shatsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Ilya M Terenin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
- Sirius University of Science and Technology, Sochi 354349, Russia
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2
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Li H, Lu N, Yu X, Liu X, Hu P, Zhu Y, Shen L, Xu J, Li Z, Guo Q, Hui H. Oroxylin A, a natural compound, mitigates the negative effects of TNFα-treated acute myelogenous leukemia cells. Carcinogenesis 2019; 39:1292-1303. [PMID: 29346508 DOI: 10.1093/carcin/bgy004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 01/10/2018] [Indexed: 12/21/2022] Open
Abstract
Tumor necrosis factor alpha (TNFα) is a complicated cytokine which is involved in proliferation and differentiation of acute myelogenous leukemia (AML) cells through a poorly understood mechanism. Mechanistic studies indicate that TNFα induced binding of PI3K subunit p85α to N-terminal truncated nuclear receptor RXRα (tRXRα) proteins, and activated AKT. The activated PI3K/AKT pathway negatively regulated differentiation of AML cells through the upregulation of c-Myc. In addition, TNFα also induced activation of nuclear factor κB (NF-κB), a nuclear transcription factor which was shown to promote cell proliferation. The present study demonstrates that oroxylin A, a natural compound isolated from Scutellariae radix, sensitizes leukemia cells to TNFα and markedly enhances TNFα-induced growth inhibition and differentiation of AML cell including human leukemia cell lines and primary AML cells. Activation of PI3K/AKT pathway could be inhibited by oroxylin A through inhibiting expression of tRXRα in NB4 and HL-60-resistant cells. Furthermore, we found that oroxylin A inhibited the activation of NF-κB and the DNA binding activity by TNFα proved by EMSA in these two AML cell lines. Moreover, in vivo studies showed that treatment with oroxylin A in combination with TNFα decreased AML cell population and prolonged survival in NOD/SCID mice with xenografts of primary AML cells. Overall, our results indicate that oroxylin A is able to inhibit the negative effects of TNFα for AML therapy, suggesting that combination of oroxylin A and TNFα have the potential to delay growth or eliminate the abnormal leukemic cells, thus representing a promising strategy for AML treatment.
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Affiliation(s)
- Hui Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Na Lu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Xiaoxuan Yu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Xiao Liu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Po Hu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Yu Zhu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China.,Department of Hematology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, Jiangsu Province, People's Republic of China
| | - Le Shen
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Jingyan Xu
- Department of Hematology, The Affiliated DrumTower Hospital of Nanjing University Medical School, Nanjing, People's Republic of China
| | - Zhiyu Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Qinglong Guo
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Hui Hui
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, Nanjing, People's Republic of China
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3
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Long MD, Singh PK, Russell JR, Llimos G, Rosario S, Rizvi A, van den Berg PR, Kirk J, Sucheston-Campbell LE, Smiraglia DJ, Campbell MJ. The miR-96 and RARγ signaling axis governs androgen signaling and prostate cancer progression. Oncogene 2019; 38:421-444. [PMID: 30120411 PMCID: PMC6336686 DOI: 10.1038/s41388-018-0450-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/25/2018] [Accepted: 06/26/2018] [Indexed: 01/22/2023]
Abstract
Expression levels of retinoic acid receptor gamma (NR1B3/RARG, encodes RARγ) are commonly reduced in prostate cancer (PCa). Therefore, we sought to establish the cellular and gene regulatory consequences of reduced RARγ expression, and determine RARγ regulatory mechanisms. RARG shRNA approaches in non-malignant (RWPE-1 and HPr1-AR) and malignant (LNCaP) prostate models revealed that reducing RARγ levels, rather than adding exogenous retinoid ligand, had the greatest impact on prostate cell viability and gene expression. ChIP-Seq defined the RARγ cistrome, which was significantly enriched at active enhancers associated with AR binding sites. Reflecting a significant genomic role for RARγ to regulate androgen signaling, RARγ knockdown in HPr1-AR cells significantly regulated the magnitude of the AR transcriptome. RARγ downregulation was explained by increased miR-96 in PCa cell and mouse models, and TCGA PCa cohorts. Biochemical approaches confirmed that miR-96 directly regulated RARγ expression and function. Capture of the miR-96 targetome by biotin-miR-96 identified that RARγ and a number of RARγ interacting co-factors including TACC1 were all targeted by miR-96, and expression of these genes were prominently altered, positively and negatively, in the TCGA-PRAD cohort. Differential gene expression analyses between tumors in the TCGA-PRAD cohort with lower quartile expression levels of RARG and TACC1 and upper quartile miR-96, compared to the reverse, identified a gene network including several RARγ target genes (e.g., SOX15) that significantly associated with worse disease-free survival (hazard ratio 2.23, 95% CI 1.58 to 2.88, p = 0.015). In summary, miR-96 targets a RARγ network to govern AR signaling, PCa progression and disease outcome.
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MESH Headings
- Adenocarcinoma/genetics
- Adenocarcinoma/metabolism
- Adenocarcinoma/mortality
- Adenocarcinoma/pathology
- Androgens
- Animals
- Cell Line, Tumor
- Disease Progression
- Enhancer Elements, Genetic
- Fetal Proteins/metabolism
- Gene Expression Regulation, Neoplastic
- Gene Regulatory Networks
- Humans
- Kaplan-Meier Estimate
- Male
- Mice
- MicroRNAs/physiology
- Microtubule-Associated Proteins/metabolism
- Neoplasm Proteins/physiology
- Neoplasms, Hormone-Dependent/genetics
- Neoplasms, Hormone-Dependent/metabolism
- Neoplasms, Hormone-Dependent/mortality
- Neoplasms, Hormone-Dependent/pathology
- Nuclear Proteins/metabolism
- Prostatic Neoplasms/genetics
- Prostatic Neoplasms/metabolism
- Prostatic Neoplasms/mortality
- Prostatic Neoplasms/pathology
- RNA Interference
- RNA, Neoplasm/physiology
- RNA, Small Interfering/genetics
- Receptors, Androgen/metabolism
- Receptors, Retinoic Acid/physiology
- Signal Transduction
- Retinoic Acid Receptor gamma
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Affiliation(s)
- Mark D Long
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center (RPCCC), Buffalo, NY, 14263, USA
| | - Prashant K Singh
- Center for Personalized Medicine, Roswell Park Comprehensive Cancer Center, Buffalo, NY, 14263, USA
| | - James R Russell
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center (RPCCC), Buffalo, NY, 14263, USA
| | - Gerard Llimos
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center (RPCCC), Buffalo, NY, 14263, USA
- Institute of Bioengineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Spencer Rosario
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center (RPCCC), Buffalo, NY, 14263, USA
| | - Abbas Rizvi
- College of Pharmacy, The Ohio State University, Columbus, OH, 43210, USA
| | - Patrick R van den Berg
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center (RPCCC), Buffalo, NY, 14263, USA
- Leiden institute of Physics, Leiden University, 2300 RA, Leiden, The Netherlands
| | - Jason Kirk
- Department of Pharmacology & Therapeutics, Roswell Park Comprehensive Cancer Center, Buffalo, NY, 14263, USA
| | - Lara E Sucheston-Campbell
- College of Pharmacy, The Ohio State University, Columbus, OH, 43210, USA
- College of Veterinary Medicine, The Ohio State University, Columbus, OH, 43210, USA
| | - Dominic J Smiraglia
- Department of Cancer Genetics and Genomics, Roswell Park Comprehensive Cancer Center (RPCCC), Buffalo, NY, 14263, USA
| | - Moray J Campbell
- Division of Pharmaceutics and Pharmaceutical Chemistry, College of Pharmacy, The Ohio State University, 536 Parks Hall, Columbus, OH, 43210, USA.
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Shatsky IN, Terenin IM, Smirnova VV, Andreev DE. Cap-Independent Translation: What's in a Name? Trends Biochem Sci 2018; 43:882-895. [PMID: 29789219 DOI: 10.1016/j.tibs.2018.04.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/15/2018] [Accepted: 04/22/2018] [Indexed: 02/05/2023]
Abstract
Eukaryotic translation initiation relies on the m7G cap present at the 5' end of all mRNAs. Some viral mRNAs employ alternative mechanisms of initiation based on internal ribosome entry. The 'IRES ideology' was adopted by researchers to explain the differential translation of cellular mRNAs when the cap recognition is suppressed. However, some cellular IRESs have already been challenged and others are awaiting their validation. As an alternative cap-independent mechanism, we propose adopting the concept of cap-independent translation enhancers (CITEs) for mammalian mRNAs. Unlike IRESs, CITEs can be located both within 5' and 3' UTRs and bind mRNA-recruiting translational components. The respective 5' UTRs are then inspected by the scanning machinery essentially in the same way as under cap-dependent translation.
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Affiliation(s)
- Ivan N Shatsky
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Leninskie Gory 1, Bldg. 40, Moscow 119992, Russia.
| | - Ilya M Terenin
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Leninskie Gory 1, Bldg. 40, Moscow 119992, Russia; Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya Str. 8-2, 119991, Moscow, Russia
| | - Victoria V Smirnova
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Leninskie Gory 1, Bldg. 40, Moscow 119992, Russia
| | - Dmitri E Andreev
- Lomonosov Moscow State University, Belozersky Institute of Physico-Chemical Biology, Leninskie Gory 1, Bldg. 40, Moscow 119992, Russia
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Xue F, Tan YH, Ren FG, Zhang YF, Chen XH, Xu ZF, Chang JM, Xu J, Gao F, Li J, Yin B, Liu HX, Wang HW. [Sensitivity of alternative spliceosomes of L-type PML-RARα fusion gene to ATO]. ZHONGHUA XUE YE XUE ZA ZHI = ZHONGHUA XUEYEXUE ZAZHI 2017; 38:554-556. [PMID: 28655105 PMCID: PMC7342965 DOI: 10.3760/cma.j.issn.0253-2727.2017.06.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - H W Wang
- Department of Hematology, the Second Hospital of Shanxi Medical University, Shanxi Key Laboratory of Molecular Diagnosis and Treatment of Blood Diseases, Taiyuan 030001, China
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Bukhari SIA, Vasudevan S. FXR1a-associated microRNP: A driver of specialized non-canonical translation in quiescent conditions. RNA Biol 2016; 14:137-145. [PMID: 27911187 DOI: 10.1080/15476286.2016.1265197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Eukaryotic protein synthesis is a multifaceted process that requires coordination of a set of translation factors in a particular cellular state. During normal growth and proliferation, cells generally make their proteome via conventional translation that utilizes canonical translation factors. When faced with environmental stress such as growth factor deprivation, or in response to biological cues such as developmental signals, cells can reduce canonical translation. In this situation, cells adapt alternative modes of translation to make specific proteins necessary for required biological functions under these distinct conditions. To date, a number of alternative translation mechanisms have been reported, which include non-canonical, cap dependent translation and cap independent translation such as IRES mediated translation. Here, we discuss one of the alternative modes of translation mediated by a specialized microRNA complex, FXR1a-microRNP that promotes non-canonical, cap dependent translation in quiescent conditions, where canonical translation is reduced due to low mTOR activity.
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Affiliation(s)
- Syed I A Bukhari
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
| | - Shobha Vasudevan
- a Center for Cancer Research, Massachusetts General Hospital, Harvard Medical School , Boston , MA , USA
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7
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Cleavage of DAP5 by coxsackievirus B3 2A protease facilitates viral replication and enhances apoptosis by altering translation of IRES-containing genes. Cell Death Differ 2015; 23:828-40. [PMID: 26586572 DOI: 10.1038/cdd.2015.145] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 09/17/2015] [Accepted: 09/25/2015] [Indexed: 12/22/2022] Open
Abstract
Cleavage of eukaryotic translation initiation factor 4G (eIF4G) by enterovirus proteases during infection leads to the shutoff of cellular cap-dependent translation, but does not affect the initiation of cap-independent translation of mRNAs containing an internal ribosome entry site (IRES). Death-associated protein 5 (DAP5), a structural homolog of eIF4G, is a translation initiation factor specific for IRES-containing mRNAs. Coxsackievirus B3 (CVB3) is a positive single-stranded RNA virus and a primary causal agent of human myocarditis. Its RNA genome harbors an IRES within the 5'-untranslated region and is translated by a cap-independent, IRES-driven mechanism. Previously, we have shown that DAP5 is cleaved during CVB3 infection. However, the protease responsible for cleavage, cleavage site and effects on the translation of target genes during CVB3 infection have not been investigated. In the present study, we demonstrated that viral protease 2A but not 3C is responsible for DAP5 cleavage, generating 45- and 52-kDa N- (DAP5-N) and C-terminal (DAP5-C) fragments, respectively. By site-directed mutagenesis, we found that DAP5 is cleaved at amino acid G434. Upon cleavage, DAP5-N largely translocated to the nucleus at the later time points of infection, whereas the DAP5-C largely remained in the cytoplasm. Overexpression of these DAP5 truncates demonstrated that DAP5-N retained the capability of initiating IRES-driven translation of apoptosis-associated p53, but not the prosurvival Bcl-2 (B-cell lymphoma 2) when compared with the full-length DAP5. Similarly, DAP5-N expression promoted CVB3 replication and progeny release; on the other hand, DAP5-C exerted a dominant-negative effect on cap-dependent translation. Taken together, viral protease 2A-mediated cleavage of DAP5 results in the production of two truncates that exert differential effects on protein translation of the IRES-containing genes, leading to enhanced host cell death.
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Shatsky IN, Dmitriev SE, Andreev DE, Terenin IM. Transcriptome-wide studies uncover the diversity of modes of mRNA recruitment to eukaryotic ribosomes. Crit Rev Biochem Mol Biol 2014; 49:164-77. [PMID: 24520918 DOI: 10.3109/10409238.2014.887051] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The conventional paradigm of translation initiation in eukaryotes states that the cap-binding protein complex eIF4F (consisting of eIF4E, eIF4G and eIF4A) plays a central role in the recruitment of capped mRNAs to ribosomes. However, a growing body of evidence indicates that this paradigm should be revised. This review summarizes the data which have been mostly accumulated in a post-genomic era owing to revolutionary techniques of transcriptome-wide analysis. Unexpectedly, these techniques have uncovered remarkable diversity in the recruitment of cellular mRNAs to eukaryotic ribosomes. These data enable a preliminary classification of mRNAs into several groups based on their requirement for particular components of eIF4F. They challenge the widely accepted concept which relates eIF4E-dependence to the extent of secondary structure in the 5' untranslated regions of mRNAs. Moreover, some mRNA species presumably recruit ribosomes to their 5' ends without the involvement of either the 5' m(7)G-cap or eIF4F but instead utilize eIF4G or eIF4G-like auxiliary factors. The long-standing concept of internal ribosome entry site (IRES)-elements in cellular mRNAs is also discussed.
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Affiliation(s)
- Ivan N Shatsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University , Moscow , Russia and
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Imran M, Park TJ, Lim IK. TIS21/BTG2/PC3 enhances downregulation of c-Myc during differentiation of HL-60 cells by activating Erk1/2 and inhibiting Akt in response to all-trans-retinoic acid. Eur J Cancer 2012; 48:2474-85. [DOI: 10.1016/j.ejca.2012.01.028] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 12/29/2011] [Accepted: 01/24/2012] [Indexed: 10/14/2022]
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10
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Fabiani E, Leone G, Giachelia M, D'alo' F, Greco M, Criscuolo M, Guidi F, Rutella S, Hohaus S, Voso MT. Analysis of genome-wide methylation and gene expression induced by 5-aza-2'-deoxycytidine identifies BCL2L10 as a frequent methylation target in acute myeloid leukemia. Leuk Lymphoma 2010; 51:2275-84. [PMID: 21077739 DOI: 10.3109/10428194.2010.528093] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Epigenetic changes play a role in the pathogenesis of myeloid malignancies, and hypomethylating agents have shown efficacy in these diseases. We studied the apoptotic effect, genome-wide methylation, and gene expression profiles in HL60 cells following 5-aza-2'-deoxycytidine (decitabine; DAC) treatment, using microarray technologies. Decitabine treatment resulted in a decrease in global DNA methylation, corresponding to 4876 probeset IDs with significantly reduced methylation levels, while the expression of 2583 IDs was modified. The integrated analysis identified 160 genes demethylated and up-regulated by decitabine, mainly including development and differentiation pathway genes. Gene targets of Polycomb group protein regulation were overrepresented in this group. Apoptosis was induced by decitabine, and apoptosis-specific PCR arrays more precisely indicated decitabine-induced up-regulation of 13 apoptosis-related genes, in particular DAP-kinase 1 and BCL2L10. Correspondingly, in primary patient samples, BCL2L10 was hypermethylated in 45% of AML, 43% of therapy-related myeloid neoplasms, 12% of MDS, and in none of the controls. In conclusion, decitabine induces global demethylation and gene expression, in particular of Polycomb target genes involved in development and differentiation pathways. The apoptotic gene BCL2L10 is a frequent target for aberrant promoter methylation in patients with acute leukemia, de novo and therapy-related.
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Affiliation(s)
- Emiliano Fabiani
- Istituto di Ematologia, Universita' Cattolica Sacro Cuore, Rome, Italy
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