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Dong Q, Gong C, Jiang Q, Liu Y, Hu Y, Wang D, Liu H, Zheng T, Song C, Wang T, Ju R, Wang C, Song D, Liu Z, Liu Y, Lu Y, Fan J, Liu M, Gao T, An Z, Zhang J, Li P, Cao C, Liu X. Identification of differentially expressed tumour-related genes regulated by UHRF1-driven DNA methylation. Sci Rep 2024; 14:18371. [PMID: 39112494 PMCID: PMC11306747 DOI: 10.1038/s41598-024-69110-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 07/31/2024] [Indexed: 08/10/2024] Open
Abstract
Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is an epigenetic regulator that plays critical roles in tumours. However, the DNA methylation alteration patterns driven by UHRF1 and the related differentially expressed tumour-related genes remain unclear. In this study, a UHRF1-shRNA MCF-7 cell line was constructed, and whole-genome bisulfite sequencing and RNA sequencing were performed. The DNA methylation alteration landscape was elucidated, and DNA methylation-altered regions (DMRs) were found to be distributed in both gene bodies and adjacent regions. The DMRs were annotated and categorized into 488 hypermethylated/1696 hypomethylated promoters and 1149 hypermethylated/5501 hypomethylated gene bodies. Through an integrated analysis with the RNA sequencing data, 217 methylation-regulated upregulated genes and 288 downregulated genes were identified, and these genes were primarily enriched in nervous system development and cancer signalling pathways. Further analysis revealed 21 downregulated oncogenes and 15 upregulated TSGs. We also showed that UHRF1 silencing inhibited cell proliferation and migration and suppressed tumour growth in vivo. Our study suggested that UHRF1 and the oncogenes or TSGs it regulates might serve as biomarkers and targets for breast cancer treatment.
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Affiliation(s)
- Qincai Dong
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Chunxue Gong
- Institute of Health Sciences, Anhui University, Hefei, 230601, China
| | - Qian Jiang
- Institute of Health Sciences, Anhui University, Hefei, 230601, China
| | - Yue Liu
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Yong Hu
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Di Wang
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Hainan Liu
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Tong Zheng
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Caiwei Song
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Tingting Wang
- Institute of Health Sciences, Anhui University, Hefei, 230601, China
| | - Ruixia Ju
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Chen Wang
- Institute of Health Sciences, Anhui University, Hefei, 230601, China
| | - Dengcen Song
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Zijing Liu
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Yuting Liu
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Yuwei Lu
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Jinlian Fan
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Mengzi Liu
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Ting Gao
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Ziqian An
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Jiaxin Zhang
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Ping Li
- Beijing Institute of Biotechnology, Beijing, 100850, China
| | - Cheng Cao
- Beijing Institute of Biotechnology, Beijing, 100850, China.
| | - Xuan Liu
- Beijing Institute of Biotechnology, Beijing, 100850, China.
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Gautam P, Gupta S, Sachan M. Comprehensive DNA methylation profiling by MeDIP-NGS identifies potential genes and pathways for epithelial ovarian cancer. J Ovarian Res 2024; 17:83. [PMID: 38627856 PMCID: PMC11022481 DOI: 10.1186/s13048-024-01395-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 03/16/2024] [Indexed: 04/19/2024] Open
Abstract
Ovarian cancer, among all gynecologic malignancies, exhibits the highest incidence and mortality rate, primarily because it is often presents with non-specific or no symptoms during its early stages. For the advancement of Ovarian Cancer Diagnosis, it is crucial to identify the potential molecular signatures that could significantly differentiate between healthy and ovarian cancerous tissues and can be used further as a diagnostic biomarker for detecting ovarian cancer. In this study, we investigated the genome-wide methylation patterns in ovarian cancer patients using Methylated DNA Immunoprecipitation (MeDIP-Seq) followed by NGS. Identified differentially methylated regions (DMRs) were further validated by targeted bisulfite sequencing for CpG site-specific methylation profiles. Furthermore, expression validation of six genes by Quantitative Reverse Transcriptase-PCR was also performed. Out of total 120 differentially methylated genes (DMGs), 68 genes were hypermethylated, and 52 were hypomethylated in their promoter region. After analysis, we identified the top 6 hub genes, namely POLR3B, PLXND1, GIGYF2, STK4, BMP2 and CRKL. Interestingly we observed Non-CpG site methylation in the case of POLR3B and CRKL which was statistically significant in discriminating ovarian cancer samples from normal controls. The most significant pathways identified were focal adhesion, the MAPK signaling pathway, and the Ras signaling pathway. Expression analysis of hypermethylated genes was correlated with the downregulation of the genes. POLR3B and GIGYF2 turned out to be the novel genes associated with the carcinogenesis of EOC. Our study demonstrated that methylation profiling through MeDIP-sequencing has effectively identified six potential hub genes and pathways that might exacerbate our understanding of underlying molecular mechanisms of ovarian carcinogenesis.
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Affiliation(s)
- Priyanka Gautam
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, Prayagraj, 211004, India
| | - Sameer Gupta
- Department of Surgical Oncology, King George Medical University, Lucknow, India
| | - Manisha Sachan
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, Prayagraj, 211004, India.
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3
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Sehgal P, Chaturvedi P. Chromatin and Cancer: Implications of Disrupted Chromatin Organization in Tumorigenesis and Its Diversification. Cancers (Basel) 2023; 15:cancers15020466. [PMID: 36672415 PMCID: PMC9856863 DOI: 10.3390/cancers15020466] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 01/04/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
A hallmark of cancers is uncontrolled cell proliferation, frequently associated with an underlying imbalance in gene expression. This transcriptional dysregulation observed in cancers is multifaceted and involves chromosomal rearrangements, chimeric transcription factors, or altered epigenetic marks. Traditionally, chromatin dysregulation in cancers has been considered a downstream effect of driver mutations. However, here we present a broader perspective on the alteration of chromatin organization in the establishment, diversification, and therapeutic resistance of cancers. We hypothesize that the chromatin organization controls the accessibility of the transcriptional machinery to regulate gene expression in cancerous cells and preserves the structural integrity of the nucleus by regulating nuclear volume. Disruption of this large-scale chromatin in proliferating cancerous cells in conventional chemotherapies induces DNA damage and provides a positive feedback loop for chromatin rearrangements and tumor diversification. Consequently, the surviving cells from these chemotherapies become tolerant to higher doses of the therapeutic reagents, which are significantly toxic to normal cells. Furthermore, the disorganization of chromatin induced by these therapies accentuates nuclear fragility, thereby increasing the invasive potential of these tumors. Therefore, we believe that understanding the changes in chromatin organization in cancerous cells is expected to deliver more effective pharmacological interventions with minimal effects on non-cancerous cells.
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Ramasamy D, Rao AKDM, Rajkumar T, Mani S. Experimental and Computational Approaches for Non-CpG Methylation Analysis. EPIGENOMES 2022; 6:epigenomes6030024. [PMID: 35997370 PMCID: PMC9397002 DOI: 10.3390/epigenomes6030024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/09/2022] [Accepted: 08/11/2022] [Indexed: 11/19/2022] Open
Abstract
Cytosine methylation adjacent to adenine, thymine, and cytosine residues but not guanine of the DNA is distinctively known as non-CpG methylation. This CA/CT/CC methylation accounts for 15% of the total cytosine methylation and varies among different cell and tissue types. The abundance of CpG methylation has largely concealed the role of non-CpG methylation. Limitations in the early detection methods could not distinguish CpG methylation from non-CpG methylation. Recent advancements in enrichment strategies and high throughput sequencing technologies have enabled the detection of non-CpG methylation. This review discusses the advanced experimental and computational approaches to detect and describe the genomic distribution and function of non-CpG methylation. We present different approaches such as enzyme-based and antibody-based enrichment, which, when coupled, can also improve the sensitivity and specificity of non-CpG detection. We also describe the current bioinformatics pipelines and their specific application in computing and visualizing the imbalance of CpG and non-CpG methylation. Enrichment modes and the computational suites need to be further developed to ease the challenges of understanding the functional role of non-CpG methylation.
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Affiliation(s)
| | | | | | - Samson Mani
- Correspondence: ; Tel.: +91-44-22350131 (ext. 196)
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Khandia R, Ali Khan A, Alexiou A, Povetkin SN, Nikolaevna VM. Codon Usage Analysis of Pro-Apoptotic Bim Gene Isoforms. J Alzheimers Dis 2022; 86:1711-1725. [DOI: 10.3233/jad-215691] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Background: Bim is a Bcl-2 homology 3 (BH3)-only proteins, a group of pro-apoptotic proteins involved in physiological and pathological conditions. Both the overexpression and under-expression of Bim protein are associated with the diseased condition, and various isoforms of Bim protein are present with differential apoptotic potential. Objective: The present study attempted to envisage the association of various molecular signatures with the codon choices of Bim isoforms. Methods: Molecular signatures like composition, codon usage, nucleotide skews, the free energy of mRNA transcript, physical properties of proteins, codon adaptation index, relative synonymous codon usage, and dinucleotide odds ratio were determined and analyzed for their associations with codon choices of Bim gene. Results: Skew analysis of the Bim gene indicated the preference of C nucleotide over G, A, and T and preference of G over T and A nucleotides was observed. An increase in C content at the first and third codon position increased gene expression while it decreased at the second codon position. Compositional constraints on nucleotide C at all three codon positions affected gene expression. The analysis revealed an exceptionally high usage of CpC dinucleotide in all the envisaged 31 isoforms of Bim. We correlated it with the requirement of rapid demethylation machinery to fine-tune the Bimgene expression. Also, mutational pressure played a dominant role in shaping codon usage bias in Bim isoforms. Conclusion: An exceptionally high usage of CpC dinucleotide in all the envisaged 31 isoforms of Bim indicates a high order selectional force to fine tune Bim gene expression.
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Affiliation(s)
- Rekha Khandia
- Department of Biochemistry and Genetics, Barkatullah University, Bhopal, India
| | - Azmat Ali Khan
- Pharmaceutical Biotechnology Laboratory, Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Athanasios Alexiou
- Novel Global Community Educational Foundation, Australia & AFNP Med, Austria
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6
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Choubey P, Kaur H, Bansal K. Modulation of DNA/RNA Methylation Signaling Mediating Metabolic Homeostasis in Cancer. Subcell Biochem 2022; 100:201-237. [PMID: 36301496 DOI: 10.1007/978-3-031-07634-3_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Nucleic acid methylation is a fundamental epigenetic mechanism that impinges upon several cellular attributes, including metabolism and energy production. The dysregulation of deoxyribonucleic acid (DNA)/ribonucleic acid (RNA) methylation can lead to metabolic rewiring in the cell, which in turn facilitates tumor development. Here, we review the current knowledge on the interplay between DNA/RNA methylation and metabolic programs in cancer cells. We also discuss the mechanistic role of these pathways in tumor development and progression.
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Affiliation(s)
- Pallawi Choubey
- Molecular Biology and Genetics Unit (MBGU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore, India
| | - Harshdeep Kaur
- Molecular Biology and Genetics Unit (MBGU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore, India
| | - Kushagra Bansal
- Molecular Biology and Genetics Unit (MBGU), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore, India.
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7
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Ramasamy D, Deva Magendhra Rao AK, Rajkumar T, Mani S. Non-CpG methylation-a key epigenetic modification in cancer. Brief Funct Genomics 2021; 20:304-311. [PMID: 34318313 DOI: 10.1093/bfgp/elab035] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/28/2021] [Accepted: 07/02/2021] [Indexed: 12/17/2022] Open
Abstract
The methylation of cytosine residues that precede adenine/thymine or other cytosine nucleotides instead of guanine in DNA is known as non-CpG methylation. It is a pronounced epigenetic modification with a central role in gene regulation similar to CpG methylation. Due to technological limitations, the locus-specific role of non-CpG methylation was scarcely understood. At present, high-throughput analyses and improved enrichment methods can elucidate the role of genome-wide non-CpG methylation distributions. Although the functional basis of non-CpG methylation in regulating gene expression control is known, its role in cancer development is yet to be ascertained. This review sheds light on the possible mechanism of non-CpG methylation in embryos and developed tissues with a special focus on cancer development and progression. In particular, the maintenance and alteration of non-CpG methylation levels and the crucial factors that determine this level of non-CpG methylation and its functional role in cancer are discussed.
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8
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Wang W, Xiong Y, Ding X, Wang L, Zhao Y, Fei Y, Zhu Y, Shen X, Tan C, Liang Z. Cathepsin L activated by mutant p53 and Egr-1 promotes ionizing radiation-induced EMT in human NSCLC. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2019; 38:61. [PMID: 30732622 PMCID: PMC6367810 DOI: 10.1186/s13046-019-1054-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 01/23/2019] [Indexed: 12/26/2022]
Abstract
BACKGROUND Ionizing radiation (IR) is one of the major clinical therapies of cancer, although it increases the epithelial-mesenchymal transition (EMT) of non-small cell lung cancer (NSCLC), unexpectedly. The cellular and molecular mechanisms underlying this role are not completely understood. METHODS We used NSCLC cell lines as well as tumor specimens from 78 patients with NSCLC to evaluate p53, Cathepsin L (CTSL) and EMT phenotypic changes. Xenograft models was also utilized to examine the roles of mutant p53 (mut-p53) and CTSL in regulating IR-induced EMT of NSCLC. RESULTS Expression of CTSL was markedly increased in human NSCLC tissues with mutant p53 (mut-p53), and p53 mutation positively correlated with metastasis of NSCLC patients. In human non-small cell lung cancer cell line, H1299 cells transfected with various p53 lentivirus vectors, mut-p53 could promote the invasion and motility of cells under IR, mainly through the EMT. This EMT process was induced by elevating intranuclear CTSL which was regulated by mut-p53 depending on Early growth response protein-1 (Egr-1) activation. In the subcutaneous tumor xenograft model, IR promoted the EMT of the cancer cells in the presence of mut-p53, owing to increase expression and nuclear transition of its downstream protein CTSL. CONCLUSION Taken together, these data reveal the role of the mut-p53/Egr-1/CTSL axis in regulating the signaling pathway responsible for IR-induced EMT.
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Affiliation(s)
- Wenjuan Wang
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China.,Department of Pharmacy, Children's Hospital of Soochow University, Suzhou, 215000, China
| | - Yajie Xiong
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China
| | - Xinyuan Ding
- Institutes for Translational Medicine, Soochow University, Suzhou, 215000, China.,Department of Pharmacy, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, 215000, China
| | - Long Wang
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China
| | - Yifan Zhao
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China
| | - Yao Fei
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China
| | - Ying Zhu
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China
| | - Xiao Shen
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China
| | - Caihong Tan
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China. .,Department of Pharmacy, Affiliated Hospital of Jiangsu University, Zhenjiang, 212000, China.
| | - Zhongqin Liang
- Department of Pharmacology, College of Pharmaceutical Sciences, Soochow University, Suzhou, 215000, China.
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9
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Koganti PP, Wang J, Cleveland B, Yao J. 17β-Estradiol Increases Non-CpG Methylation in Exon 1 of the Rainbow Trout (Oncorhynchus mykiss) MyoD Gene. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2017; 19:321-327. [PMID: 28578488 DOI: 10.1007/s10126-017-9756-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 05/22/2017] [Indexed: 06/07/2023]
Abstract
MyoD is an important myogenic transcription factor necessary for the differentiation of myogenic precursor cells (MPC) to form mature myotubes, a process essential for muscle growth. Epigenetic markers such as CpH methylation are known gene regulators that are important for the differentiation process. In this study, we investigated whether DNA methylation is a potential mechanism associated with the ability of 17β-estradiol (E2) to reduce MyoD gene expression and muscle growth in rainbow trout. Rainbow trout received a single intraperitoneal injection of E2 or the injection vehicle (control). Skeletal muscle was collected 24 h post injection and analyzed for DNA methylation within the MyoD gene and the expression of DNA methyltransferases. CpG islands of the MyoD gene were predicted using MethPrimer software, and these regions were PCR amplified and analyzed using bisulfite sequencing. The percent methylation of the targeted CpG did not differ between control and E2-treated fish. However, percent CpH methylation in the MyoD exon 1 region was elevated with E2 treatment. Two of the methylated CpH sites were located in conserved transcription factor binding motifs, estrogen response element (ERE), and Myc binding site. Quantitative real-time PCR analysis revealed a significant increase in expression of DNA methyltransferases, Dnmt3a and Dnmt3b, in E2-treated muscle, suggesting an increased genome methylation. Differential CpH methylation in MyoD gene of control and E2-treated fish suggests an epigenetic mechanism through which E2 decreases MyoD gene expression and contributes to reduced muscle growth.
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Affiliation(s)
- Prasanthi P Koganti
- Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, WV, 26506-6108, USA
| | - Jian Wang
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Beth Cleveland
- National Center for Cool and Cold Water Aquaculture, USDA/ARS, Kearneysville, WV, USA
| | - Jianbo Yao
- Division of Animal and Nutritional Sciences, West Virginia University, Morgantown, WV, 26506-6108, USA.
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10
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Methyl-Cytosine-Driven Structural Changes Enhance Adduction Kinetics of an Exon 7 fragment of the p53 Gene. Sci Rep 2017; 7:40890. [PMID: 28102315 PMCID: PMC5244379 DOI: 10.1038/srep40890] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 12/12/2016] [Indexed: 01/26/2023] Open
Abstract
Methylation of cytosine (C) at C-phosphate-guanine (CpG) sites enhances reactivity of DNA towards electrophiles. Mutations at CpG sites on the p53 tumor suppressor gene that can result from these adductions are in turn correlated with specific cancers. Here we describe the first restriction-enzyme-assisted LC-MS/MS sequencing study of the influence of methyl cytosines (MeC) on kinetics of p53 gene adduction by model metabolite benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), using methodology applicable to correlate gene damage sites for drug and pollutant metabolites with mutation sites. This method allows direct kinetic measurements by LC-MS/MS sequencing for oligonucleotides longer than 20 base pairs (bp). We used MeC and non-MeC (C) versions of a 32 bp exon 7 fragment of the p53 gene. Methylation of 19 cytosines increased the rate constant 3-fold for adduction on G at the major reactive CpG in codon 248 vs. the non-MeC fragment. Rate constants for non-CpG codons 244 and 243 were not influenced significantly by MeC. Conformational and hydrophobicity changes in the MeC-p53 exon 7 fragment revealed by CD spectra and molecular modeling increase the BPDE binding constant to G in codon 248 consistent with a pathway in which preceding reactant binding greatly facilitates the rate of covalent SN2 coupling.
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11
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Shang X, Su J, Wan Q, Su J. CpA/CpG methylation of CiMDA5 possesses tight association with the resistance against GCRV and negatively regulates mRNA expression in grass carp, Ctenopharyngodon idella. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2015; 48:86-94. [PMID: 25260715 DOI: 10.1016/j.dci.2014.09.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 09/19/2014] [Accepted: 09/19/2014] [Indexed: 06/03/2023]
Abstract
Melanoma differentiation-associated gene 5 (MDA5) plays a crucial role in recognizing intracellular viral infection, activating the interferon regulatory factor pathways as well as inducing antiviral response. While the antiviral regulatory mechanism of MDA5 remains unclear. In the present study, CiMDA5 (Ctenopharyngodon idella MDA5) against grass carp reovirus (GCRV) would be initially revealed from the perspective of DNA methylation, a pivotal epigenetic modification. Two CpG islands (CGIs) were predicted located in the first exon of CiMDA5, of which the first CpG island was 427 bp in length possessed 29 candidate CpG loci and 34 CpA loci, and the second one was 130 bp in length involving 7 CpG loci as well as 10 CpA loci. By bisulfite sequencing PCR (BSP), the methylation statuses were detected in spleen of 70 individuals divided into resistant/susceptible groups post challenge experiment, and the resistance-association analysis was performed with Chi-square test. Quantitative real-time RT-PCR (qRT-PCR) was carried out to explore the relationship between DNA methylation and gene expression in CiMDA5. Results indicated that the methylation levels of CpA/CpG sites at +200, +202, +204, +207 nt, which consisted of a putative densely methylated element (DME), were significantly higher in the susceptible group than those in the resistant group. Meanwhile, the average transcription of CiMDA5 was down-regulated in the susceptible individuals compared with the resistant individuals. Evidently, the DNA methylation may be the negative modulator of CiMDA5 antiviral expression. Collectively, the methylation levels of CiMDA5 demonstrated the tight association with the resistance against GCRV and the negative-regulated roles in mRNA expression. This study first discovered the resistance-associated gene modulated by DNA methylation in teleost, preliminary revealed the underlying regulatory mechanism of CiMDA5 transcription against GCRV as well as laid a theoretical foundation on molecular nosogenesis of hemorrhagic diseases in C. idella.
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Affiliation(s)
- Xueying Shang
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Jianguo Su
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China.
| | - Quanyuan Wan
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
| | - Juanjuan Su
- College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China
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12
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Patil V, Ward RL, Hesson LB. The evidence for functional non-CpG methylation in mammalian cells. Epigenetics 2014; 9:823-8. [PMID: 24717538 DOI: 10.4161/epi.28741] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In mammalian genomes, the methylation of cytosine residues within CpG dinucleotides is crucial to normal development and cell differentiation. However, methylation of cytosines in the contexts of CpA, CpT, and CpC (non-CpG methylation) has been reported for decades, yet remains poorly understood. In recent years, whole genome bisulphite sequencing (WGBS) has confirmed significant levels of non-CpG methylation in specific tissues and cell types. Non-CpG methylation has several properties that distinguish it from CpG methylation. Here we review the literature describing non-CpG methylation in mammalian cells, describe the important characteristics that distinguish it from CpG methylation, and discuss its functional importance.
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Affiliation(s)
- Vibha Patil
- Adult Cancer Program; Lowy Cancer Research Centre and Prince of Wales Clinical School; University of New South Wales; Sydney, NSW Australia
| | - Robyn L Ward
- Adult Cancer Program; Lowy Cancer Research Centre and Prince of Wales Clinical School; University of New South Wales; Sydney, NSW Australia
| | - Luke B Hesson
- Adult Cancer Program; Lowy Cancer Research Centre and Prince of Wales Clinical School; University of New South Wales; Sydney, NSW Australia
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13
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Truong M, Yang B, Wagner J, Desotelle J, Jarrard DF. Analysis of promoter non-CG methylation in prostate cancer. Epigenomics 2013; 5:65-71. [PMID: 23414321 DOI: 10.2217/epi.12.67] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND In vertebrates, DNA methylation occurs primarily at CG dinucleotides but recently, non-CG methylation has been found at appreciable levels in embryonic stem cells. MATERIALS & METHODS To assess non-CG methylation in cancer, we compared the extent of non-CG methylation at several biologically important CG islands in prostate cancer and normal cell lines. An assessment of the promoter CG islands EVX1 and FILIP1L demonstrates a fourfold higher rate of non-CG methylation at EVX1 compared with FILIP1L across all cell lines. These loci are densely methylated at CG sites in cancer. RESULTS No significant difference in non-CG methylation was demonstrated between cancer and normal. Treatment of cancer cell lines with 5-azacytidine significantly reduced methylation within EVX1 at CG and CC sites, preferentially. CONCLUSION Non-CG methylation does not correlate with CG methylation at hypermethylated promoter regions in cancer. Furthermore, global inhibition of DNA methyltransferases does not affect all methylated cytosines uniformly.
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Affiliation(s)
- Matthew Truong
- Department of Urology, University of Wisconsin School of Medicine & Public Health, Madison, WI, USA
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14
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You BR, Park WH. Zebularine inhibits the growth of A549 lung cancer cells via cell cycle arrest and apoptosis. Mol Carcinog 2013; 53:847-57. [PMID: 23661569 DOI: 10.1002/mc.22042] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 04/04/2013] [Indexed: 01/03/2023]
Abstract
Zebularine (Zeb) is a DNA methyltransferase (DNMT) inhibitor to that has an anti-tumor effect. Here, we evaluated the anti-growth effect of Zeb on A549 lung cancer cells in relation to reactive oxygen species (ROS) levels. Zeb inhibited the growth of A549 cells with an IC50 of approximately 70 µM at 72 h. Cell cycle analysis indicated that Zeb induced an S phase arrest in A549 cells. Zeb also induced A549 cell death, which was accompanied by the loss of mitochondrial membrane potential (MMP; ΔΨm ), Bcl-2 decrease, Bax increase, p53 increase and activation of caspase-3 and -8. In contrast, Zeb mildly inhibited the growth of human pulmonary fibroblast (HPF) normal cells and lead to a G1 phase arrest. Zeb did not induce apoptosis in HPF cells. In relation to ROS level, Zeb increased ROS level in A549 cells and induced glutathione (GSH) depletion. The well-known antioxidant, N-acetyl cysteine (NAC) prevented the death of Zeb-treated A549 cells. Moreover, Zeb increased the level of thioredoxin reductase 1 (TrxR1) in A549 cells. While the overexpression of TrxR1 attenuated death and ROS level in Zeb-treated A549 cells, the downregulation of TrxR1 intensified death and ROS level in these cells. In conclusion, Zeb inhibited the growth of A549 lung cancer cells via cell cycle arrest and apoptosis. The inhibition was influenced by ROS and TrxR1 levels.
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Affiliation(s)
- Bo Ra You
- Department of Physiology, Medical School, Research Institute for Endocrine Sciences, Chonbuk National University, Jeonju, Republic of Korea
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15
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Bulic A, Postberg J, Fischer A, Jönsson F, Reuter G, Lipps HJ. A permissive chromatin structure is adopted prior to site-specific DNA demethylation of developmentally expressed genes involved in macronuclear differentiation. Epigenetics Chromatin 2013; 6:5. [PMID: 23497475 PMCID: PMC3608066 DOI: 10.1186/1756-8935-6-5] [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: 11/12/2012] [Accepted: 01/17/2013] [Indexed: 01/15/2023] Open
Abstract
Background DNA methylation and demethylation are important epigenetic regulatory mechanisms in eukaryotic cells and, so far, only partially understood. We exploit the minimalistic biological ciliate system to understand the crosstalk between DNA modification and chromatin structure. In the macronucleus of these cells, the DNA is fragmented into individual short DNA molecules, each representing a functional expression and replication unit. Therefore, long range epigenomic interaction can be excluded in this system. Results In the stichotrichous ciliate Stylonychia lemnae, cytosine methylation occurs in a small subset of macronuclear nanochromosomes expressed only during sexual reproduction. Methylation pattern shows similarity to that observed in fungi and Drosophila. Cytosine methylation correlates with gene activity and chromatin structure. Upon gene activation, cytosines become demethylated and a redistribution of histone post-translational modifications (PTMs) takes place. Evidence is presented that the formation of a permissive chromatin structure in the vicinity of the 5meCs precedes cytosine methylation and is probably a necessary prerequisite for their demethylation. Shortly after demethylation of cytosines occurs, the parental macronucleus degenerates, a new macronucleus is formed from a micronuclear derivative and the specific methylation pattern is transmitted from the germline micronucleus to the new macronucleus. Conclusions We show that very few, or even only one, discrete methylated cytosines are required to assign regulatory functions at a specific locus. Furthermore, evidence is provided that a permissive chromatin structure is probably a necessary prerequisite for the demethylation of specific cytosines. Our results allow us to propose a mechanistic model for the biological function of cytosine methylation in the ciliate cell and its regulation during the cell cycle.
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Affiliation(s)
- Aneta Bulic
- Institute of Cell Biology, Centre for Biomedical Education and Research, Witten/Herdecke University, Witten, Germany.
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Zebularine-induced apoptosis in Calu-6 lung cancer cells is influenced by ROS and GSH level changes. Tumour Biol 2013; 34:1145-53. [DOI: 10.1007/s13277-013-0656-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Accepted: 01/09/2013] [Indexed: 10/27/2022] Open
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DNA methylation inhibitors in cancer: recent and future approaches. Biochimie 2012; 94:2280-96. [PMID: 22967704 DOI: 10.1016/j.biochi.2012.07.025] [Citation(s) in RCA: 169] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2012] [Accepted: 07/30/2012] [Indexed: 12/14/2022]
Abstract
This review presents the different human DNA methyltransferases (DNMTs), their biological roles, their mechanisms of action and their role in cancer. The description of assays for detecting DNMT inhibitors (DNMTi) follows. The different known DNMTi are reported along with their advantages, drawbacks and clinical trials. A discussion on the features of the future DNMT inhibitors will conclude this review.
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Pardo CE, Darst RP, Nabilsi NH, Delmas AL, Kladde MP. Simultaneous single-molecule mapping of protein-DNA interactions and DNA methylation by MAPit. ACTA ACUST UNITED AC 2011; Chapter 21:Unit 21.22. [PMID: 21732317 DOI: 10.1002/0471142727.mb2122s95] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Sites of protein binding to DNA are inferred from footprints or spans of protection against a probing reagent. In most protocols, sites of accessibility to a probe are detected by mapping breaks in DNA strands. As discussed in this unit, such methods obscure molecular heterogeneity by averaging cuts at a given site over all DNA strands in a sample population. The DNA methyltransferase accessibility protocol for individual templates (MAPit), an alternative method described in this unit, localizes protein-DNA interactions by probing with cytosine-modifying DNA methyltransferases followed by bisulfite sequencing. Sequencing individual DNA products after amplification of bisulfite-converted sequences permits assignment of the methylation status of every enzyme target site along a single DNA strand. Use of the GC-methylating enzyme M.CviPI allows simultaneous mapping of chromatin accessibility and endogenous CpG methylation. MAPit is therefore the only footprinting method that can detect subpopulations of molecules with distinct patterns of protein binding or chromatin architecture and correlate them directly with the occurrence of endogenous methylation. Additional advantages of MAPit methylation footprinting as well as considerations for experimental design and potential sources of error are discussed.
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Affiliation(s)
- Carolina E Pardo
- Department of Biochemistry and Molecular Biology and UF Shands Cancer Center Program in Cancer Genetics, Epigenetics and Tumor Virology, University of Florida College of Medicine, Gainesville, Florida, USA
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Denisov EV, Sukhanovskaya TV, Dultseva TS, Malinovskaya EA, Litviakov NV, Slonimskaya EM, Choinzonov EL, Cherdyntseva NV. Coordination of TP53 abnormalities in breast cancer: data from analysis of TP53 polymorphisms, loss of heterozygosity, methylation, and mutations. Genet Test Mol Biomarkers 2011; 15:901-7. [PMID: 21810023 DOI: 10.1089/gtmb.2011.0038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
AIMS We have studied whether TP53 rs1042522, rs17878362, and rs1625895 alleles having a protective effect against breast cancer (BC) will be lost in tumors, whereas those allowing disease development will be retained. METHODS Analysis of TP53 polymorphisms was performed in blood leukocytes and tumors from 80 Caucasian BC patients. In addition, TP53 loss of heterozygosity (LOH), methylation, and mutations were studied in tumor DNA of BC individuals with loss of alleles of TP53 polymorphisms. RESULTS In breast tumors of patients heterozygous for TP53 polymorphisms, we detected loss of rs1042522 C and G and rs17878362 A2 alleles; however, the loss of the C allele was preferential. We found that loss of TP53 alleles, namely rs1042522 C, has been caused by an LOH mechanism, namely TP53 deletions, whereas TP53 point mutations frequently occurred in the retained G allele (p=0.03). In addition, we showed that BC patients with rs1042522 CC genotype were characterized by only unifocal tumors and decreased frequency of lymph node metastases (p=0.03). CONCLUSIONS Taken together, we showed the preferential loss of the rs1042522 C allele, which is protective against BC progression, in breast tumors. Also, the loss of the C allele, which encodes p53 protein with the best DNA repair capability according to literature data, may create prerequisites for mutations, but not for methylation in a retained G variant, as we found here. However, these results need to be confirmed because of the limited statistical power of the present study and the small sampling.
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Affiliation(s)
- Evgeny V Denisov
- Department of Experimental Oncology, Cancer Research Institute, Siberian Branch of Russian Academy of Medical Sciences, Kooperativny St. 5, Tomsk, Russian Federation.
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Anastasiadou C, Malousi A, Maglaveras N, Kouidou S. Human epigenome data reveal increased CpG methylation in alternatively spliced sites and putative exonic splicing enhancers. DNA Cell Biol 2011; 30:267-75. [PMID: 21545276 DOI: 10.1089/dna.2010.1094] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The role of gene body methylation, which represents a major part of methylation in DNA, remains mostly unknown. Evidence based on the CpG distribution associates its presence with nucleosome positioning and alternative splicing. Recently, it was also shown that cytosine methylation influences splicing. However, to date, there is no methylation-based data on the association of methylation with alternative splicing and the distribution in exonic splicing enhancers (ESEs). We presently report that, based on the computational analysis of the Human Epigenome Project data, CpG hypermethylation (>80%) is frequent in alternatively spliced sites (particularly in noncanonical) but not in alternate promoters. The methylation frequency increases in sequences containing multiple putative ESEs. However, significant differences in the extent of methylation are observed among different ESEs. Specifically, moderate levels of methylation, ranging from 20% to 80%, are frequent in SRp55-binding elements, which are associated with response to extracellular conditions, but not in SF2/ASF, primarily responsible for alternative splicing, or in CpG islands. Finally, methylation is more frequent in the presence of AT repeats and CpGs separated by 10 nucleotides and lower in adjacent CpGs, probably indicating its dependence on helical formations and on the presence of nucleosome positioning-related sequences. In conclusion, our results show the regulation of methylation in ESEs and support its involvement in alternative splicing.
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Affiliation(s)
- Christina Anastasiadou
- Laboratory of Medical Informatics, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
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21
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Wen W, Wen J, Lu L, Liu H, Yang J, Cheng H, Che W, Li L, Zhang G. Metabolites of arsenic and increased DNA damage of p53 gene in arsenic plant workers. Toxicol Appl Pharmacol 2011; 254:41-7. [DOI: 10.1016/j.taap.2011.04.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Revised: 04/18/2011] [Accepted: 04/21/2011] [Indexed: 10/18/2022]
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AL-QASEM ABEERJ, TOULIMAT MOHAMED, ELDALI ABDELMONEIMM, TULBAH ASMA, AL-YOUSEF NUJOUD, AL-DAIHAN SOOADK, AL-TASSAN NADA, AL-TWEIGERI TAHER, ABOUSSEKHRA ABDELILAH. TP53 genetic alterations in Arab breast cancer patients: Novel mutations, pattern and distribution. Oncol Lett 2011; 2:363-369. [PMID: 22866089 PMCID: PMC3410563 DOI: 10.3892/ol.2011.236] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 01/03/2011] [Indexed: 01/11/2023] Open
Abstract
Breast cancer remains a worldwide public health concern. The incidence and mortality of breast cancer varies significantly in ethnically and geographically distinct populations. In the Kingdom of Saudi Arabia (KSA) breast cancer has shown an increase in incidence and is characterized by early onset and aggressiveness. The tumor suppressor TP53 gene is a crucial genetic factor that plays a significant role in breast carcinogenesis. Furthermore, studies have shown a correlation between certain p53 mutations and response to therapy in breast cancer. In the present study, TP53 mutations were identified by direct sequencing of the gene (exons 4-9) from 119 breast cancer tissues. The prevalence of TP53 mutations in Arab breast cancer patients living in the KSA is among the highest in the world (40%). Notably, 73% of the patients whose tumors harbored p53 mutations were less than 50 years of age. Furthermore, for the first time, we identified 7 novel mutations and 16 mutations in breast cancer tissues. Notably, all the novel point mutations were found in exon 4, wherein 29% of the mutations were localized. Furthermore, an excess of G:C→A:T transitions (49%) at non-CpG sites was noted, suggesting exposure to particular environmental carcinogens such as N-nitroso compounds. The results indicate that the TP53 gene plays a significant role in breast carcinogenesis and the early onset of the disease among Arab female individuals.
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Affiliation(s)
- ABEER J. AL-QASEM
- Department of Biological and Medical Research, King Saud University, Riyadh, Saudi Arabia
| | - MOHAMED TOULIMAT
- Department of Pathology, King Saud University, Riyadh, Saudi Arabia
| | - ABDELMONEIM M. ELDALI
- Department of Biostatistics, Epidemiology and Scientific Computing, King Saud University, Riyadh, Saudi Arabia
| | - ASMA TULBAH
- Department of Pathology, King Saud University, Riyadh, Saudi Arabia
| | - NUJOUD AL-YOUSEF
- Department of Biological and Medical Research, King Saud University, Riyadh, Saudi Arabia
| | | | - NADA AL-TASSAN
- Oncology Center, King Faisal Specialist Hospital and Research Center, King Saud University, Riyadh, Saudi Arabia
| | - TAHER AL-TWEIGERI
- Department of Biochemistry, King Saud University, Riyadh, Saudi Arabia
| | - ABDELILAH ABOUSSEKHRA
- Department of Biological and Medical Research, King Saud University, Riyadh, Saudi Arabia
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Krikelis D, Tzimagiorgis G, Georgiou E, Destouni C, Agorastos T, Haitoglou C, Kouidou S. Frequent presence of incomplete HPV16 E7 ORFs in lung carcinomas: Memories of viral infection. J Clin Virol 2010; 49:169-74. [DOI: 10.1016/j.jcv.2010.07.020] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 07/21/2010] [Accepted: 07/30/2010] [Indexed: 11/30/2022]
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24
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Fuso A, Ferraguti G, Grandoni F, Ruggeri R, Scarpa S, Strom R, Lucarelli M. Early demethylation of non-CpG, CpC-rich, elements in the myogenin 5'-flanking region: a priming effect on the spreading of active demethylation. Cell Cycle 2010; 9:3965-76. [PMID: 20935518 DOI: 10.4161/cc.9.19.13193] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The dynamic changes and structural patterns of DNA methylation of genes without CpG islands are poorly characterized. The relevance of CpG to the non-CpG methylation equilibrium in transcriptional repression is unknown. In this work, we analyzed the DNA methylation pattern of the 5'-flanking of the myogenin gene, a positive regulator of muscle differentiation with no CpG island and low CpG density, in both C2C12 muscle satellite cells and embryonic muscle. Embryonic brain was studied as a non-expressing tissue. High levels of both CpG and non-CpG methylation were observed in non-expressing experimental conditions. Both CpG and non-CpG methylation rapidly dropped during muscle differentiation and myogenin transcriptional activation, with an active demethylation dynamics. Non-CpG demethylation occurred more rapidly than CpG demethylation. Demethylation spread from initially highly methylated short CpC-rich elements to a virtually unmethylated status. These short elements have a high CpC content and density, share some motifs and largely coincide with putative recognition sequences of some differentiation-related transcription factors. Our findings point to a dynamically controlled equilibrium between CpG and non-CpG active demethylation in the transcriptional control of tissue-specific genes. The short CpC-rich elements are new structural features of the methylation machinery, whose functions may include priming the complete demethylation of a transcriptionally crucial DNA region.
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Affiliation(s)
- Andrea Fuso
- Department of Surgery P. Valdoni, Sapienza University of Rome, Italy
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25
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Pardo CE, Carr IM, Hoffman CJ, Darst RP, Markham AF, Bonthron DT, Kladde MP. MethylViewer: computational analysis and editing for bisulfite sequencing and methyltransferase accessibility protocol for individual templates (MAPit) projects. Nucleic Acids Res 2010; 39:e5. [PMID: 20959287 PMCID: PMC3017589 DOI: 10.1093/nar/gkq716] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Bisulfite sequencing is a widely-used technique for examining cytosine DNA methylation at nucleotide resolution along single DNA strands. Probing with cytosine DNA methyltransferases followed by bisulfite sequencing (MAPit) is an effective technique for mapping protein-DNA interactions. Here, MAPit methylation footprinting with M.CviPI, a GC methyltransferase we previously cloned and characterized, was used to probe hMLH1 chromatin in HCT116 and RKO colorectal cancer cells. Because M.CviPI-probed samples contain both CG and GC methylation, we developed a versatile, visually-intuitive program, called MethylViewer, for evaluating the bisulfite sequencing results. Uniquely, MethylViewer can simultaneously query cytosine methylation status in bisulfite-converted sequences at as many as four different user-defined motifs, e.g. CG, GC, etc., including motifs with degenerate bases. Data can also be exported for statistical analysis and as publication-quality images. Analysis of hMLH1 MAPit data with MethylViewer showed that endogenous CG methylation and accessible GC sites were both mapped on single molecules at high resolution. Disruption of positioned nucleosomes on single molecules of the PHO5 promoter was detected in budding yeast using M.CviPII, increasing the number of enzymes available for probing protein-DNA interactions. MethylViewer provides an integrated solution for primer design and rapid, accurate and detailed analysis of bisulfite sequencing or MAPit datasets from virtually any biological or biochemical system.
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Affiliation(s)
- Carolina E Pardo
- Department of Biochemistry and Molecular Biology, University of Florida Shands Cancer Center Program in Cancer Genetics, Epigenetics and Tumor Virology, Gainesville, FL 32610-3633, USA
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26
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Huang L, Frampton G, Liang LJ, DeMorrow S. Aberrant DNA methylation profile in cholangiocarcinoma. World J Gastrointest Pathophysiol 2010; 1:23-9. [PMID: 21607139 PMCID: PMC3097943 DOI: 10.4291/wjgp.v1.i2.23] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Revised: 05/25/2010] [Accepted: 06/01/2010] [Indexed: 02/06/2023] Open
Abstract
Cholangiocarcinoma (CCA) is a notoriously lethal epithelial cancer originating from the biliary system. As radical resection offers a poor success rate and limited effective adjuvant modalities exist in its advanced stage, the disease leads to a fairly poor prognosis. As the incidence of CCA is increasing, although the mortality rate remains stable, and few other definite etiologies have yet to be established, renewing our knowledge of its fundamental carcinogenesis is advisable. The latest advances in molecular carcinogenesis have highlighted the roles of epigenetic perturbations and cancer-related inflammation in CCA. This review focuses on the reciprocal effects between aberrant DNA methylation and inflammatory microenvironment in CCA.
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27
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Vassilenko EI, Muttray AF, Schulte PM, Baldwin SA. Variations in p53-like cDNA sequence are correlated with mussel haemic neoplasia: A potential molecular-level tool for biomonitoring. Mutat Res 2010; 701:145-52. [PMID: 20541620 DOI: 10.1016/j.mrgentox.2010.06.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 05/27/2010] [Accepted: 06/01/2010] [Indexed: 02/07/2023]
Abstract
Several bivalve species, including mussels (Mytilus spp.) and clams (Mya spp.), are susceptible to a leukemia-like disease called haemic neoplasia that has been known to decimate whole populations. Previous studies of molecular processes associated with late stages of this disease have implicated analogs of the p53 tumour suppressor protein family in disease etiology. We detected synonymous single nucleotide polymorphisms (SNPs) in the coding region sequence of p53-like cDNA from Mytilus trossulus (bay mussel) that differ between normal and neoplastic haemolymph. SNPs were located at positions 182, 392 and 821 bp. Most (94%) of the late leukemic animals sampled from cages in Burrard Inlet (British Columbia, Canada) had the same p53-like genotype, C182T G392G C821T, whereas 75% of the healthy animals were homozygous at positions C182C and T821T, independent of the genotype at the 392 bp position. As well, we detected an increased number of allelic variants in the leukemic animals that may arise from separate somatic mutation events in haemocyte precursors or from additional p53-like gene copies in polyploidy. Therefore, detection of these SNPs may provide a useful genetic biomarker for efficient monitoring of mussel population health.
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Affiliation(s)
- Ekaterina I Vassilenko
- Chemical and Biological Engineering, University of British Columbia, 2360 East Mall, Vancouver, British Columbia V6T 1Z3, Canada
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28
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Meister GE, Chandrasegaran S, Ostermeier M. Heterodimeric DNA methyltransferases as a platform for creating designer zinc finger methyltransferases for targeted DNA methylation in cells. Nucleic Acids Res 2010; 38:1749-59. [PMID: 20007601 PMCID: PMC2836561 DOI: 10.1093/nar/gkp1126] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 11/10/2009] [Accepted: 11/13/2009] [Indexed: 12/17/2022] Open
Abstract
The ability to target methylation to specific genomic sites would further the study of DNA methylation's biological role and potentially offer a tool for silencing gene expression and for treating diseases involving abnormal hypomethylation. The end-to-end fusion of DNA methyltransferases to zinc fingers has been shown to bias methylation to desired regions. However, the strategy is inherently limited because the methyltransferase domain remains active regardless of whether the zinc finger domain is bound at its cognate site and can methylate non-target sites. We demonstrate an alternative strategy in which fragments of a DNA methyltransferase, compromised in their ability to methylate DNA, are fused to two zinc fingers designed to bind 9 bp sites flanking a methylation target site. Using the naturally heterodimeric DNA methyltransferase M.EcoHK31I, which methylates the inner cytosine of 5'-YGGCCR-3', we demonstrate that this strategy can yield a methyltransferase capable of significant levels of methylation at the target site with undetectable levels of methylation at non-target sites in Escherichia coli. However, some non-target methylation could be detected at higher expression levels of the zinc finger methyltransferase indicating that further improvements will be necessary to attain the desired exclusive target specificity.
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Affiliation(s)
- Glenna E. Meister
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 and Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Srinivasan Chandrasegaran
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 and Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205, USA
| | - Marc Ostermeier
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218 and Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205, USA
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Tang M, Xu W, Wang Q, Xiao W, Xu R. Potential of DNMT and its Epigenetic Regulation for Lung Cancer Therapy. Curr Genomics 2009; 10:336-52. [PMID: 20119531 PMCID: PMC2729998 DOI: 10.2174/138920209788920994] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 06/22/2009] [Accepted: 06/23/2009] [Indexed: 02/07/2023] Open
Abstract
Lung cancer, the leading cause of mortality in both men and women in the United States, is largely diagnosed at its advanced stages that there are no effective therapeutic alternatives. Although tobacco smoking is the well established cause of lung cancer, the underlying mechanism for lung tumorigenesis remains poorly understood. An important event in tumor development appears to be the epigenetic alterations, especially the change of DNA methylation patterns, which induce the most tumor suppressor gene silence. In one scenario, DNA methyltransferase (DNMT) that is responsible for DNA methylation accounts for the major epigenetic maintenance and alternation. In another scenario, DNMT itself is regulated by the environment carcinogens (smoke), epigenetic and genetic information. DNMT not only plays a pivotal role in lung tumorigenesis, but also is a promising molecular bio-marker for early lung cancer diagnosis and therapy. Therefore the elucidation of the DNMT and its related epigenetic regulation in lung cancer is of great importance, which may expedite the overcome of lung cancer.
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Affiliation(s)
- Mingqing Tang
- Engineering Research Center of Molecular Medicine, Ministry of Education, 362021, China & Institute of Molecular Medicine, Huaqiao University, Fujian, 362021, China
| | - William Xu
- Faculty of Science, University of New South Wales, 2052, Australia
| | - Qizhao Wang
- Engineering Research Center of Molecular Medicine, Ministry of Education, 362021, China & Institute of Molecular Medicine, Huaqiao University, Fujian, 362021, China
| | - Weidong Xiao
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ruian Xu
- Engineering Research Center of Molecular Medicine, Ministry of Education, 362021, China & Institute of Molecular Medicine, Huaqiao University, Fujian, 362021, China
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McKnight DA, Suzanne Hart P, Hart TC, Hartsfield JK, Wilson A, Wright JT, Fisher LW. A comprehensive analysis of normal variation and disease-causing mutations in the human DSPP gene. Hum Mutat 2009; 29:1392-404. [PMID: 18521831 DOI: 10.1002/humu.20783] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Within nine dentin dysplasia (DD) (type II) and dentinogenesis imperfecta (type II and III) patient/families, seven have 1 of 4 net -1 deletions within the approximately 2-kb coding repeat domain of the DSPP gene while the remaining two patients have splice-site mutations. All frameshift mutations are predicted to change the highly soluble DSPP protein into proteins with long hydrophobic amino acid repeats that could interfere with processing of normal DSPP and/or other secreted matrix proteins. We propose that all previously reported missense, nonsense, and splice-site DSPP mutations (all associated with exons 2 and 3) result in dominant phenotypes due to disruption of signal peptide-processing and/or related biochemical events that also result in interference with protein processing. This would bring the currently known dominant forms of the human disease phenotype in agreement with the normal phenotype of the heterozygous null Dspp (-/+) mice. A study of 188 normal human chromosomes revealed a hypervariable DSPP repeat domain with extraordinary rates of change including 20 slip-replication indel events and 37 predominantly C-to-T transition SNPs. The most frequent transition in the primordial 9-basepair (bp) DNA repeat was a sense-strand CpG site while a CpNpG (CAG) transition was the second most frequent SNP. Bisulfite-sequencing of genomic DNA showed that the DSPP repeat can be methylated at both motifs. This suggests that, like plants and some animals, humans methylate some CpNpG sequences. Analysis of 37 haplotypes of the highly variable DSPP gene from geographically diverse people suggests it may be a useful autosomal marker in human migration studies.
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Affiliation(s)
- Dianalee A McKnight
- Craniofacial and Skeletal Diseases Branch, National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Bethesda, Maryland 20892, USA
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Kouidou S, Malousi A, Kyventidis A, Fragou A, Maglaveras N. G:C > A:T mutations and potential epigenetic regulation of p53 in breast cancer. Breast Cancer Res Treat 2007; 106:351-60. [PMID: 17505880 DOI: 10.1007/s10549-007-9514-y] [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] [Received: 10/31/2006] [Accepted: 01/03/2007] [Indexed: 01/03/2023]
Abstract
Analysis of germline p53 mutations in breast cancer reveals that the Li-Fraumeni and Li-Fraumeni-like syndromes are mostly related to the loss of initiation codon 133 of regulatory TP53 isoforms (Delta133p53). In eight codons of exons 5-8 (including 133), mutations are frequent in Li-Fraumeni-related, but scarce in sporadic breast cancer, while in six more codons they are frequent both in familial and sporadic breast cancers. At the proximity of these codons, we observed in somatic mutation databases, 16 codons (minihotspots mostly in exons 7, 8) which undergo frequent G:C > A:T transitions (non-CpG) in all sporadic cancers. In addition, in sporadic breast cancer we observed 35 adjacent codons in which the following types of mutation are observed: frequent G:C > A:T transitions at CCs/GGs, frequent silent mutations in exons 5,6 and suppressed nonsense mutations (5 codons, few records). Non-CpG G:C > A:T transitions in the 35 codons are rare in familial cancers (p53, BRCA1, or BRCA2-related), but frequent in sporadic cancers in organs where Li-Fraumeni-related carcinogenesis is common e.g. adrenal cortex, soft tissues. These data are in support of the following tissue-specific processes: in sporadic breast cancer (sarcomas etc.), loss of methylation sites (in 35 codons mostly next to codon 133), might lead to loss of silencing of TP53 isoforms which are suppressed in these tissues. On the contrary, "spreading" of cytosine methylation (asymmetric) in a G:C-rich region next to common hotspots (codons 238-252 in minihotspots) and mutagenesis probably destabilizes all tissues. Frequent C > T activation at non-CpG is also observed in prostate sporadic cancer, which similarly to breast, undergoes age-related crisis. The above data reveal that tissue-specific epigenetic regulatory mechanisms might be involved in p53 instability.
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Affiliation(s)
- Sofia Kouidou
- Department of Biological Chemistry, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece.
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Kouidou S, Malousi A, Maglaveras N. Methylation and repeats in silent and nonsense mutations of p53. Mutat Res 2006; 599:167-77. [PMID: 16620878 DOI: 10.1016/j.mrfmmm.2006.03.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2005] [Revised: 02/22/2006] [Accepted: 03/01/2006] [Indexed: 12/16/2022]
Abstract
All exonic CG sequences in p53 are methylated; this epigenetic modification is correlated with frequent G:C-->A:T transitions in p53. Recent reports reveal the presence in p53 of non-CG methylation in CC and CCC sequences, complementary to sites of selective guanosine adduct formation (GG and GGG), and the association of genetic instability with methylation at repetitive sequences. We presently investigated the distribution of methylation sites and repetitive elements in silent and nonsense p53 mutations (2051) among the IARC's TP53 somatic mutation database for exons 5-8. Silent mutations are nonrandom, but mostly involve G:C-->A:T transitions (62%); in particular C-->T mutations (39% of all silent mutations) are mostly correlated with CC and CCC sequences, while G-->A mutations with GG sequences. Sequence analysis of all non-G:C-->A:T silent mutations reveals the frequent formation of new methylation sites (CG), new CCC and GGG sequences in the resulting sequence, refinement of symmetry elements at interrupted microsatellite-like sequences and formation of small repeats (55.3%). The G:C-->A:T silent mutations characterize cancers associated with cigarette smoking (e.g. bladder or lung and bronchus cancer versus colorectal cancer); on the contrary, non-G:C-->A:T silent mutations have similar frequencies in most cancers. Nonsense mutations in exons 5-8, all resulting in mutants lacking amino acids 307-393, which are crucial for p53 activity, were also analyzed. The frequency of nonsense mutations is higher at methylated sites or repeats 1-2 nucleotides removed from methylation sites. Frameshift mutations are also more frequent at repeated sequences. The frequent G:C-->A:T silent mutations could indicate that CC and CCC sequences of exons 5-8 are occasionally targets of non-CpG methylation of cytosine. This process of de novo methylation in the presence of microsatellite-like sequences and small repeats might influence the genetic stability of a variety of genes.
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Affiliation(s)
- Sofia Kouidou
- Laboratory of Biological Chemistry, School of Medicine, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
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