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Mokhtari K, Peymani M, Rashidi M, Hushmandi K, Ghaedi K, Taheriazam A, Hashemi M. Colon cancer transcriptome. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2023; 180-181:49-82. [PMID: 37059270 DOI: 10.1016/j.pbiomolbio.2023.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 03/31/2023] [Accepted: 04/06/2023] [Indexed: 04/16/2023]
Abstract
Over the last four decades, methodological innovations have continuously changed transcriptome profiling. It is now feasible to sequence and quantify the transcriptional outputs of individual cells or thousands of samples using RNA sequencing (RNA-seq). These transcriptomes serve as a connection between cellular behaviors and their underlying molecular mechanisms, such as mutations. This relationship, in the context of cancer, provides a chance to unravel tumor complexity and heterogeneity and uncover novel biomarkers or treatment options. Since colon cancer is one of the most frequent malignancies, its prognosis and diagnosis seem to be critical. The transcriptome technology is developing for an earlier and more accurate diagnosis of cancer which can provide better protectivity and prognostic utility to medical teams and patients. A transcriptome is a whole set of expressed coding and non-coding RNAs in an individual or cell population. The cancer transcriptome includes RNA-based changes. The combined genome and transcriptome of a patient may provide a comprehensive picture of their cancer, and this information is beginning to affect treatment decision-making in real-time. A full assessment of the transcriptome of colon (colorectal) cancer has been assessed in this review paper based on risk factors such as age, obesity, gender, alcohol use, race, and also different stages of cancer, as well as non-coding RNAs like circRNAs, miRNAs, lncRNAs, and siRNAs. Similarly, they have been examined independently in the transcriptome study of colon cancer.
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Affiliation(s)
- Khatere Mokhtari
- Department of Modern Biology, ACECR Institute of Higher Education (Isfahan Branch), Isfahan, Iran
| | - Maryam Peymani
- Department of Biology, Faculty of Basic Sciences, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran.
| | - Mohsen Rashidi
- Department Pharmacology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, 4815733971, Iran; The Health of Plant and Livestock Products Research Center, Mazandaran University of Medical Sciences, Sari, 4815733971, Iran
| | - Kiavash Hushmandi
- Department of Food Hygiene and Quality Control, Division of Epidemiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Kamran Ghaedi
- Department of Cell and Molecular Biology and Microbiology, Faculty of Biological Science and Technology, University of Isfahan, Isfahan, Iran.
| | - Afshin Taheriazam
- Farhikhtegan Medical Convergence Sciences Research Center, Farhikhtegan Hospital Tehran Medical Sciences, Islamic Azad University, Tehran, Iran; Department of Orthopedics, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
| | - Mehrdad Hashemi
- Farhikhtegan Medical Convergence Sciences Research Center, Farhikhtegan Hospital Tehran Medical Sciences, Islamic Azad University, Tehran, Iran; Department of Genetics, Faculty of Advanced Science and Technology, Tehran Medical Sciences, Islamic Azad University, Tehran, Iran.
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Gutierrez A, Demond H, Brebi P, Ili CG. Novel Methylation Biomarkers for Colorectal Cancer Prognosis. Biomolecules 2021; 11:1722. [PMID: 34827720 PMCID: PMC8615818 DOI: 10.3390/biom11111722] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/03/2021] [Accepted: 11/09/2021] [Indexed: 12/24/2022] Open
Abstract
Colorectal cancer (CRC) comprises the third most common cancer worldwide and the second regarding number of deaths. In order to make a correct and early diagnosis to predict metastasis formation, biomarkers are an important tool. Although there are multiple signaling pathways associated with cancer progression, the most recognized are the MAPK pathway, p53 pathway, and TGF-β pathway. These pathways regulate many important functions in the cell, such as cell cycle regulation, proliferation, differentiation, and metastasis formation, among others. Changes in expression in genes belonging to these pathways are drivers of carcinogenesis. Often these expression changes are caused by mutations; however, epigenetic changes, such as DNA methylation, are increasingly acknowledged to play a role in the deregulation of oncogenic genes. This makes DNA methylation changes an interesting biomarkers in cancer. Among the newly identified biomarkers for CRC metastasis INHBB, SMOC2, BDNF, and TBRG4 are included, all of which are highly deregulated by methylation and closely associated with metastasis. The identification of such biomarkers in metastasis of CRC may allow a better treatment and early identification of cancer formation in order to perform better diagnostics and improve the life expectancy.
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Affiliation(s)
| | | | - Priscilla Brebi
- Millennium Institute on Immunology and Immunotherapy, Laboratory of Integrative Biology (LIBi), Centro de Excelencia en Medicina Traslacional (CEMT), Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, Temuco 4810296, Chile; (A.G.); (H.D.)
| | - Carmen Gloria Ili
- Millennium Institute on Immunology and Immunotherapy, Laboratory of Integrative Biology (LIBi), Centro de Excelencia en Medicina Traslacional (CEMT), Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, Temuco 4810296, Chile; (A.G.); (H.D.)
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Zhang Y, Zhang L, Sun H, Liu Y, Xu J, Huang H, Fu J, Zhang D, Tian T, Zhao Y, Wang G. Inhibitory immune checkpoints PDCD-1 and LAG-3 hypermethylation may reduce the risk of colorectal cancer. Mol Med 2021; 27:114. [PMID: 34544358 PMCID: PMC8454079 DOI: 10.1186/s10020-021-00373-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 09/05/2021] [Indexed: 12/24/2022] Open
Abstract
Background Changes in DNA methylation of immunosuppressive checkpoints may impact express and consequently affect antigen processing and presentation by tumor cells and facilitates evasion of immunosurveillance and lead to colorectal cancer (CRC). This study is to investigate the effect of PDCD-1, LAG-3 methylation statuses in peripheral blood leukocytes on CRC risk. Methods GSE51032 dataset from Gene Expression Omnibus comprised of 166 CRC patients and 424 normal samples was used to identify significantly differentially methylated CpG sites of the two genes. A case–control study with 390 CRC patients and 397 cancer-free controls was carried out to validate the relationship between the methylation levels of the two genes and CRC susceptibility and then estimated their interactions with environmental factors on CRC risk. Results In the GSE51032 dataset, cg06291111 (PDCD-1) and cg10191002 (LAG-3) were screened as the candidate CpG sites for the following study. There were significant associations between hypermethylation of PDCD-1 and LAG-3 and lower risk of CRC (ORadj = 0.322, 95% CI 0.197–0.528; ORadj = 0.666, 95% CI 0.446–0.5996, respectively). Moreover, the results in case–control study showed similar trend, that hypermethylation of PDCD-1 and LAG-3 were associated with lower CRC risk (ORadj = 0.448, 95% CI 0.322–0.622; ORadj = 0.417, 95% CI 0.301–0.578, respectively). A synergistic interaction between LAG-3 hypermethylation and intake of eggs on CRC risk was observed. There were combination effects between hypermethylation of PDCD-1 and LAG-3 and environmental factors on CRC risk. Conclusions PDCD-1 and LAG-3 may potentially serve as blood-based predictive biomarkers for CRC risk. Supplementary Information The online version contains supplementary material available at 10.1186/s10020-021-00373-5.
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Affiliation(s)
- Yuanyuan Zhang
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China
| | - Lei Zhang
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China
| | - Hongru Sun
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China
| | - Ying Liu
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China
| | - Jing Xu
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China
| | - Hao Huang
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China
| | - Jinming Fu
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China
| | - Ding Zhang
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China
| | - Tian Tian
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China.
| | - Yashuang Zhao
- Department of Epidemiology, Public Health College of Harbin Medical University, 157 Baojian Street, Nangang District, Harbin, 150081, Heilongjiang, People's Republic of China.
| | - Guiyu Wang
- Department of Colorectal Cancer Surgery, The Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Street, Nangang District, Harbin, 150001, Heilongjiang, People's Republic of China.
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Jansen RJ, Tong L, Argos M, Jasmine F, Rakibuz-Zaman M, Sarwar G, Islam MT, Shahriar H, Islam T, Rahman M, Yunus M, Kibriya MG, Baron JA, Ahsan H, Pierce BL. The effect of age on DNA methylation in whole blood among Bangladeshi men and women. BMC Genomics 2019; 20:704. [PMID: 31506065 PMCID: PMC6734473 DOI: 10.1186/s12864-019-6039-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/16/2019] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND It is well-known that methylation changes occur as humans age, however, understanding how age-related changes in DNA methylation vary by sex is lacking. In this study, we characterize the effect of age on DNA methylation in a sex-specific manner and determine if these effects vary by genomic context. We used the Illumina HumanMethylation 450 K array and DNA derived from whole blood for 400 adult participants (189 males and 211 females) from Bangladesh to identify age-associated CpG sites and regions and characterize the location of these age-associated sites with respect to CpG islands (vs. shore, shelf, or open sea) and gene regions (vs. intergenic). We conducted a genome-wide search for age-associated CpG sites (among 423,604 sites) using a reference-free approach to adjust for cell type composition (the R package RefFreeEWAS) and performed an independent replication analysis of age-associated CpGs. RESULTS The number of age-associated CpGs (p < 5 x 10- 8) were 986 among men and 3479 among women of which 2027(63.8%) and 572 (64.1%) replicated (using Bonferroni adjusted p < 1.2 × 10- 5). For both sexes, age-associated CpG sites were more likely to be hyper-methylated with increasing age (compared to hypo-methylated) and were enriched in CpG islands and promoter regions compared with other locations and all CpGs on the array. Although we observed strong correlation between chronological age and previously-developed epigenetic age models (r ≈ 0.8), among our top (based on lowest p-value) age-associated CpG sites only 12 for males and 44 for females are included in these prediction models, and the median chronological age compared to predicted age was 44 vs. 51.7 in males and 45 vs. 52.1 in females. CONCLUSIONS Our results describe genome-wide features of age-related changes in DNA methylation. The observed associations between age and methylation were generally consistent for both sexes, although the associations tended to be stronger among women. Our population may have unique age-related methylation changes that are not captured in the established methylation-based age prediction model we used, which was developed to be non-tissue-specific.
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Affiliation(s)
- Rick J Jansen
- Department of Public Health, North Dakota State University, Fargo, ND, USA
- Genomics and Bioinformatics Program, North Dakota State University, Fargo, ND, USA
- Biostatistics Core Facility, North Dakota State University, Fargo, ND, USA
| | - Lin Tong
- Department of Public Health Sciences, University of Chicago, 5841 S. Maryland Ave., W264, MC2000, Chicago, IL, 60637, USA
| | - Maria Argos
- Divison of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, Chicago, IL, USA
| | - Farzana Jasmine
- Department of Public Health Sciences, University of Chicago, 5841 S. Maryland Ave., W264, MC2000, Chicago, IL, 60637, USA
| | | | - Golam Sarwar
- UChicago Research Bangladesh Mohakhali, Dhaka, 1230, Bangladesh
| | | | - Hasan Shahriar
- UChicago Research Bangladesh Mohakhali, Dhaka, 1230, Bangladesh
| | - Tariqul Islam
- UChicago Research Bangladesh Mohakhali, Dhaka, 1230, Bangladesh
| | - Mahfuzar Rahman
- UChicago Research Bangladesh Mohakhali, Dhaka, 1230, Bangladesh
- Research and Evaluation Division BRAC, Mohakhali, Dhaka, 1212, Bangladesh
| | - Md Yunus
- International Centre for Diarrhoeal Disease Research Bangladesh, Dhaka, 1000, Bangladesh
| | - Muhammad G Kibriya
- Department of Public Health Sciences, University of Chicago, 5841 S. Maryland Ave., W264, MC2000, Chicago, IL, 60637, USA
| | - John A Baron
- Department of Epidemiology, Gillings School of Global Public Health, University of North Caroline, Chapel Hill, NC, USA
| | - Habibul Ahsan
- Department of Public Health Sciences, University of Chicago, 5841 S. Maryland Ave., W264, MC2000, Chicago, IL, 60637, USA.
- Department of Medicine, The University of Chicago, Chicago, IL, USA.
- Department of Human Genetics and Comprehensive Cancer Center, The University of Chicago, Chicago, IL, USA.
| | - Brandon L Pierce
- Department of Public Health Sciences, University of Chicago, 5841 S. Maryland Ave., W264, MC2000, Chicago, IL, 60637, USA.
- Department of Human Genetics and Comprehensive Cancer Center, The University of Chicago, Chicago, IL, USA.
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Counteraction of Oxidative Stress by Vitamin E Affects Epigenetic Regulation by Increasing Global Methylation and Gene Expression of MLH1 and DNMT1 Dose Dependently in Caco-2 Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:3734250. [PMID: 29854080 PMCID: PMC5944233 DOI: 10.1155/2018/3734250] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Revised: 01/18/2018] [Accepted: 01/29/2018] [Indexed: 02/06/2023]
Abstract
Obesity- or diabetes-induced oxidative stress is discussed as a major risk factor for DNA damage. Vitamin E and many polyphenols exhibit antioxidative activities with consequences on epigenetic regulation of inflammation and DNA repair. The present study investigated the counteraction of oxidative stress by vitamin E in the colorectal cancer cell line Caco-2 under normal (1 g/l) and high (4.5 g/l) glucose cell culture condition. Malondialdehyde (MDA) as a surrogate marker of lipid peroxidation and reactive oxygen species (ROS) was analyzed. Gene expression and promoter methylation of the DNA repair gene MutL homolog 1 (MLH1) and the DNA methyltransferase 1 (DNMT1) as well as global methylation by LINE-1 were investigated. Results revealed a dose-dependent counteracting effect of vitamin E on H2O2-induced oxidative stress. Thereby, 10 μM vitamin E proved to be more efficient than did 50 μM in reducing MDA. Further, an induction of MLH1 and DNMT1 gene expression was noticed, accompanied by an increase in global methylation. Whether LINE-1 hypomethylation is a cause or effect of oxidative stress is still unclear. In conclusion, supplementation of exogenous antioxidants like vitamin E in vitro exhibits beneficial effects concerning oxidative stress as well as epigenetic regulation involved in DNA repair.
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Shalaby SM, El-Shal AS, Abdelaziz LA, Abd-Elbary E, Khairy MM. Promoter methylation and expression of DNA repair genes MGMT and ERCC1 in tissue and blood of rectal cancer patients. Gene 2018; 644:66-73. [DOI: 10.1016/j.gene.2017.10.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 09/30/2017] [Accepted: 10/18/2017] [Indexed: 01/26/2023]
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Abstract
Methylation-Sensitive High Resolution Melting (MS-HRM) is an in-tube, PCR-based method to detect methylation levels at specific loci of interest. A unique primer design facilitates a high sensitivity of the assays enabling detection of down to 0.1-1% methylated alleles in an unmethylated background.Primers for MS-HRM assays are designed to be complementary to the methylated allele, and a specific annealing temperature enables these primers to anneal both to the methylated and the unmethylated alleles thereby increasing the sensitivity of the assays. Bisulfite treatment of the DNA prior to performing MS-HRM ensures a different base composition between methylated and unmethylated DNA, which is used to separate the resulting amplicons by high resolution melting.The high sensitivity of MS-HRM has proven useful for detecting cancer biomarkers in a noninvasive manner in urine from bladder cancer patients, in stool from colorectal cancer patients, and in buccal mucosa from breast cancer patients. MS-HRM is a fast method to diagnose imprinted diseases and to clinically validate results from whole-epigenome studies. The ability to detect few copies of methylated DNA makes MS-HRM a key player in the quest for establishing links between environmental exposure, epigenetic changes, and disease.
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Affiliation(s)
- Dianna Hussmann
- Institute of Biomedicine, Aarhus University, Bartholins Allé 6, Aarhus C, 8000, Denmark
| | - Lise Lotte Hansen
- Institute of Biomedicine, Aarhus University, Bartholins Allé 6, Aarhus C, 8000, Denmark.
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Reppe S, Datta HK, Gautvik KM. Omics analysis of human bone to identify genes and molecular networks regulating skeletal remodeling in health and disease. Bone 2017; 101:88-95. [PMID: 28450214 DOI: 10.1016/j.bone.2017.04.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2016] [Revised: 04/13/2017] [Accepted: 04/22/2017] [Indexed: 12/11/2022]
Abstract
The skeleton is a metabolically active organ throughout life where specific bone cell activity and paracrine/endocrine factors regulate its morphogenesis and remodeling. In recent years, an increasing number of reports have used multi-omics technologies to characterize subsets of bone biological molecular networks. The skeleton is affected by primary and secondary disease, lifestyle and many drugs. Therefore, to obtain relevant and reliable data from well characterized patient and control cohorts are vital. Here we provide a brief overview of omics studies performed on human bone, of which our own studies performed on trans-iliacal bone biopsies from postmenopausal women with osteoporosis (OP) and healthy controls are among the first and largest. Most other studies have been performed on smaller groups of patients, undergoing hip replacement for osteoarthritis (OA) or fracture, and without healthy controls. The major findings emerging from the combined studies are: 1. Unstressed and stressed bone show profoundly different gene expression reflecting differences in bone turnover and remodeling and 2. Omics analyses comparing healthy/OP and control/OA cohorts reveal characteristic changes in transcriptomics, epigenomics (DNA methylation), proteomics and metabolomics. These studies, together with genome-wide association studies, in vitro observations and transgenic animal models have identified a number of genes and gene products that act via Wnt and other signaling systems and are highly associated to bone density and fracture. Future challenge is to understand the functional interactions between bone-related molecular networks and their significance in OP and OA pathogenesis, and also how the genomic architecture is affected in health and disease.
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Affiliation(s)
- Sjur Reppe
- Oslo University Hospital, Department of Medical Biochemistry, Oslo, Norway; Lovisenberg Diakonale Hospital, Unger-Vetlesen Institute, Oslo, Norway.
| | - Harish K Datta
- Pathology Department, Biochemistry Section, James Cook University Hospital, Middlesbrough, UK; Musculoskeletal Research Group, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Kaare M Gautvik
- Lovisenberg Diakonale Hospital, Unger-Vetlesen Institute, Oslo, Norway; University of Oslo, Institute of Basic Medical Sciences, Oslo, Norway
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Reppe S, Lien TG, Hsu YH, Gautvik VT, Olstad OK, Yu R, Bakke HG, Lyle R, Kringen MK, Glad IK, Gautvik KM. Distinct DNA methylation profiles in bone and blood of osteoporotic and healthy postmenopausal women. Epigenetics 2017. [PMID: 28650214 DOI: 10.1080/15592294.2017.1345832] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
DNA methylation affects expression of associated genes and may contribute to the missing genetic effects from genome-wide association studies of osteoporosis. To improve insight into the mechanisms of postmenopausal osteoporosis, we combined transcript profiling with DNA methylation analyses in bone. RNA and DNA were isolated from 84 bone biopsies of postmenopausal donors varying markedly in bone mineral density (BMD). In all, 2529 CpGs in the top 100 genes most significantly associated with BMD were analyzed. The methylation levels at 63 CpGs differed significantly between healthy and osteoporotic women at 10% false discovery rate (FDR). Five of these CpGs at 5% FDR could explain 14% of BMD variation. To test whether blood DNA methylation reflect the situation in bone (as shown for other tissues), an independent cohort was selected and BMD association was demonstrated in blood for 13 of the 63 CpGs. Four transcripts representing inhibitors of bone metabolism-MEPE, SOST, WIF1, and DKK1-showed correlation to a high number of methylated CpGs, at 5% FDR. Our results link DNA methylation to the genetic influence modifying the skeleton, and the data suggest a complex interaction between CpG methylation and gene regulation. This is the first study in the hitherto largest number of postmenopausal women to demonstrate a strong association among bone CpG methylation, transcript levels, and BMD/fracture. This new insight may have implications for evaluation of osteoporosis stage and susceptibility.
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Affiliation(s)
- Sjur Reppe
- a Department of Medical Biochemistry , Oslo University Hospital , Oslo , Norway.,b Lovisenberg Diakonale Hospital, Unger-Vetlesen Institute , Oslo , Norway.,c University of Oslo, Institute of Basic Medical Sciences , Oslo , Norway
| | - Tonje G Lien
- d Department of Mathematics , University of Oslo , Oslo , Norway
| | - Yi-Hsiang Hsu
- e Hebrew SeniorLife Institute for Aging Research and Harvard Medical School , Boston , MA , USA.,f Broad Institute of MIT and Harvard , Cambridge , MA , USA.,g Molecular and Physiological Sciences Program, Harvard School of Public Health , Boston , MA , USA.,h Gerontology Division , Department of Medicine , Beth Israel Deaconess Medical Center , Boston , MA , USA
| | - Vigdis T Gautvik
- c University of Oslo, Institute of Basic Medical Sciences , Oslo , Norway
| | - Ole K Olstad
- a Department of Medical Biochemistry , Oslo University Hospital , Oslo , Norway
| | - Rona Yu
- e Hebrew SeniorLife Institute for Aging Research and Harvard Medical School , Boston , MA , USA
| | - Hege G Bakke
- i Center for Psychopharmacology, Diakonhjemmet Hospital , Oslo , Norway
| | - Robert Lyle
- j Department of Medical Genetics , Oslo University Hospital , Oslo , Norway.,k Department of Medical Genetics , University of Oslo , Oslo , Norway
| | | | - Ingrid K Glad
- d Department of Mathematics , University of Oslo , Oslo , Norway
| | - Kaare M Gautvik
- b Lovisenberg Diakonale Hospital, Unger-Vetlesen Institute , Oslo , Norway.,c University of Oslo, Institute of Basic Medical Sciences , Oslo , Norway
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DNA methylation analysis of cancer-related genes in oral epithelial cells of healthy smokers. Arch Oral Biol 2015; 60:825-33. [PMID: 25791328 DOI: 10.1016/j.archoralbio.2015.02.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 11/18/2014] [Accepted: 02/24/2015] [Indexed: 12/22/2022]
Abstract
AIM The aim of this study was to investigate the smoking habit influence on DNA methylation status in the promoters of the cancer related-genes MLH1, hTERT and TP53 in oral epithelial cells of healthy subjects. MATERIALS AND METHODS DNA methylation analysis was performed using methylation-sensitive restriction enzymes (MSRE) in oral epithelial cells from non-smokers, smokers and ex-smokers. RESULTS The investigated CpG dinucleotides located at HhaI and HpaII sites in the MLH1 gene promoter were observed to be fully methylated in the majority of DNA samples from the smoker group and statistical differences were found between non-smokers and smokers and between smokers and ex-smokers (p<0.05). The same was observed in the hTERT gene promoter at HhaI sites (p<0.05) and for HpaII sites the unmethylated condition was more frequent in smokers in comparison to non-smokers (p<0.05). For TP53, no differences were found among groups (p>0.05), with the fully methylated condition found to be a common event in healthy oral epithelial cells. CONCLUSION We conclude that smoking may induce changes in DNA methylation status in cancer-related genes of oral epithelial cells and that the cessation of smoking is capable of reversing this process. Based on our data, we suggest that DNA methylation status of the hTERT and MLH1 gene promoters are promising markers for screening a set of smoking-related alterations in oral cells.
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Zheng CG, Jin C, Ye LC, Chen NZ, Chen ZJ. Clinicopathological significance and potential drug target of O6-methylguanine-DNA methyltransferase in colorectal cancer: a meta-analysis. Tumour Biol 2015; 36:5839-48. [PMID: 25716203 DOI: 10.1007/s13277-015-3254-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 02/10/2015] [Indexed: 12/18/2022] Open
Abstract
Emerging evidence indicates that O(6)-methylguanine-DNA methyltransferase (MGMT) is a candidate for tumor suppression in several types of human tumors including colorectal cancer (CRC). However, the correlation between MGMT hypermethylation and clinicopathological characteristics of CRC remains unclear. In this study, we conducted a systematic review and meta-analysis to quantitatively evaluate the effects of MGMT hypermethylation on the incidence of CRC and clinicopathological characteristics. A comprehensive literature search was done from Web of Science, the Cochrane Library Database, PubMed, EMBASE, CINAHL, and the Chinese Biomedical Database for related research publications written in English and Chinese. Methodological quality of the studies was also evaluated. Analyses of pooled data were performed with Review Manager 5.2. Odds ratio (OR) and hazard ratio (HR) were calculated and summarized, respectively. Final analysis from 28 eligible studies was performed. MGMT hypermethylation is found to be significantly higher in CRC than in normal colorectal mucosa, the pooled OR from 13 studies including 1085 CRC and 899 normal colorectal mucosa, OR = 6.04, 95 % confidence interval (CI) = 4.69-7.77, p < 0.00001. MGMT hypermethylation is also significantly higher in colorectal adenoma than in normal colorectal mucosa, but it is significantly less compared to that in CRC patients. Interestingly, MGMT hypermethylation is correlated with sex status and is significantly higher in female than in male. MGMT hypermethylation is also associated with high levels of microsatellite instability (MSI). The pooled HR for overall survival (OS) shows that MGMT hypermethylation is not associated with worse survival in CRC patients. The results of this meta-analysis suggest that MGMT hypermethylation is associated with an increased risk and high levels of MSI and may play an important role in CRC initiation. However, MGMT hypermethylation may play an important role in the early stage of CRC progression and development, as well as having limited value in prediction of prognosis in CRC patients. We also discussed that MGMT may serve as a potential drug target of CRC.
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Affiliation(s)
- Chen-Guo Zheng
- Department of Coloproctology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, 325000, People's Republic of China
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