1
|
He Q, Wei Y, Zhu H, Liang Q, Chen P, Li S, Song Y, Liu L, Wang B, Xu X, Dong Y. The combined effect of MTHFR C677T and A1298C polymorphisms on the risk of digestive system cancer among a hypertensive population. Discov Oncol 2024; 15:97. [PMID: 38565713 PMCID: PMC10987447 DOI: 10.1007/s12672-024-00960-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 03/29/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND AND PURPOSE The enzyme methylenetetrahydrofolate reductase (MTHFR) plays a crucial role in directing folate species towards nucleotide synthesis or DNA methylation. The MTHFR polymorphisms C677T and A1298C have been linked to cancer susceptibility, but the evidence supporting this association has been equivocal. To investigate the individual and joint associations between MTHFR C677T, A1298C, and digestive system cancer in a Chinese hypertensive population, we conducted a population-based case-control study involving 751 digestive system cancer cases and one-to-one matched controls from the China H-type Hypertension Registry Study (CHHRS). METHODS We utilized the conditional logistic regression model to evaluate multivariate odds ratios (ORs) and 95% confidence intervals (CIs) of digestive system cancer. RESULTS The analysis revealed a significantly lower risk of digestive system cancer in individuals with the CT genotype (adjusted OR: 0.71; 95% CI 0.52, 0.97; P = 0.034) and TT genotype (adjusted OR: 0.57; 95% CI 0.40, 0.82; P = 0.003; P for trend = 0.003) compared to those with the 677CC genotype. Although A1298C did not show a measurable association with digestive system cancer risk, further stratification of 677CT genotype carriers by A1298C homozygotes (AA) and heterozygotes (AC) revealed a distinct trend within these subgroups. CONCLUSION These findings indicate a potential protective effect against digestive system cancer associated with the T allele of MTHFR C677T. Moreover, we observed that the presence of different combinations of MTHFR polymorphisms may contribute to varying susceptibilities to digestive system cancer.
Collapse
Affiliation(s)
- Qiangqiang He
- Shenzhen International Graduate School, Tsinghua University, University Town of Shenzhen, No. 2279, Lishui Road. Nanshan District, Shenzhen, 518055, Guangdong, China
- Shenzhen Evergreen Medical Institute, Shenzhen, 518057, Guangdong, China
| | - Yaping Wei
- College of Public Health, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China
| | - Hehao Zhu
- School of Science, China Pharmaceutical University, Nanjing, 211198, Jiangsu, China
| | - Qiongyue Liang
- State Key Laboratory of Natural Medicines, Research Center of Biostatistics and Computational Pharmacy, China Pharmaceutical University, Nanjing, 211198, Jiangsu, China
| | - Ping Chen
- College of Pharmacy, Jinan University, Guangzhou, 510632, Guangdong, China
- Inspection and Testing Center, Key Laboratory of Cancer FSMP for State Market Regulation, Shenzhen, 518057, China
| | - Shuqun Li
- Department of Gastrointestinal Surgery/Clinical Nutrition, Capital Medical University Affiliated Beijing Shijitan Hospital, Beijing, 100038, China
| | - Yun Song
- Shenzhen Evergreen Medical Institute, Shenzhen, 518057, Guangdong, China
| | - Lishun Liu
- Shenzhen International Graduate School, Tsinghua University, University Town of Shenzhen, No. 2279, Lishui Road. Nanshan District, Shenzhen, 518055, Guangdong, China
- Shenzhen Evergreen Medical Institute, Shenzhen, 518057, Guangdong, China
- Guangdong Key Laboratory of H-Type Hypertension and Stroke Precision Prevention Research and Development Enterprise, Shenzhen, 518057, China
| | - Binyan Wang
- Shenzhen Evergreen Medical Institute, Shenzhen, 518057, Guangdong, China
- Institute of Biomedicine, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Xiping Xu
- National Clinical Research Center for Kidney Disease, State Key Laboratory for Organ Failure Research, Guangdong Provincial Key Laboratory of Renal Failure Research, Guangzhou Regenerative Medicine and Health, Guangdong Laboratory, Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, Guangdong, China
| | - Yuhan Dong
- Shenzhen International Graduate School, Tsinghua University, University Town of Shenzhen, No. 2279, Lishui Road. Nanshan District, Shenzhen, 518055, Guangdong, China.
| |
Collapse
|
2
|
Wu MT, Ye WT, Wang YC, Chen PM, Liu JY, Tai CK, Tang FY, Li JR, Liu CC, Chiang EPI. MTHFR Knockdown Assists Cell Defense against Folate Depletion Induced Chromosome Segregation and Uracil Misincorporation in DNA. Int J Mol Sci 2021; 22:ijms22179392. [PMID: 34502300 PMCID: PMC8431311 DOI: 10.3390/ijms22179392] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/11/2021] [Accepted: 08/19/2021] [Indexed: 12/14/2022] Open
Abstract
Folate depletion causes chromosomal instability by increasing DNA strand breakage, uracil misincorporation, and defective repair. Folate mediated one-carbon metabolism has been suggested to play a key role in the carcinogenesis and progression of hepatocellular carcinoma (HCC) through influencing DNA integrity. Methylenetetrahydrofolate reductase (MTHFR) is the enzyme catalyzing the irreversible conversion of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate that can control folate cofactor distributions and modulate the partitioning of intracellular one-carbon moieties. The association between MTHFR polymorphisms and HCC risk is inconsistent and remains controversial in populational studies. We aimed to establish an in vitro cell model of liver origin to elucidate the interactions between MTHFR function, folate status, and chromosome stability. In the present study, we (1) examined MTHFR expression in HCC patients; (2) established cell models of liver origin with stabilized inhibition of MTHFR using small hairpin RNA delivered by a lentiviral vector, and (3) investigated the impacts of reduced MTHFR and folate status on cell cycle, methyl group homeostasis, nucleotide biosynthesis, and DNA stability, all of which are pathways involved in DNA integrity and repair and are critical in human tumorigenesis. By analyzing the TCGA/GTEx datasets available within GEPIA2, we discovered that HCC cancer patients with higher MTHFR had a worse survival rate. The shRNA of MTHFR (shMTHFR) resulted in decreased MTHFR gene expression, MTHFR protein, and enzymatic activity in human hepatoma cell HepG2. shMTHFR tended to decrease intracellular S-adenosylmethionine (SAM) contents but folate depletion similarly decreased SAM in wildtype (WT), negative control (Neg), and shMTHFR cells, indicating that in cells of liver origin, shMTHFR does not exacerbate the methyl group supply in folate depletion. shMTHFR caused cell accumulations in the G2/M, and cell population in the G2/M was inversely correlated with MTHFR gene level (r = −0.81, p < 0.0001), MTHFR protein expression (r = −0.8; p = 0.01), and MTHFR enzyme activity (r = −0.842; p = 0.005). Folate depletion resulted in G2/M cell cycle arrest in WT and Neg but not in shMTHFR cells, indicating that shMTHFR does not exacerbate folate depletion-induced G2/M cell cycle arrest. In addition, shMTHFR promoted the expression and translocation of nuclei thymidine synthetic enzyme complex SHMT1/DHFR/TYMS and assisted folate-dependent de novo nucleotide biosynthesis under folate restriction. Finally, shMTHFR promoted nuclear MLH1/p53 expression under folate deficiency and further reduced micronuclei formation and DNA uracil misincorporation under folate deficiency. In conclusion, shMTHFR in HepG2 induces cell cycle arrest in G2/M that may promote nucleotide supply and assist cell defense against folate depletion-induced chromosome segregation and uracil misincorporation in the DNA. This study provided insight into the significant impact of MTHFR function on chromosome stability of hepatic tissues. Data from the present study may shed light on the potential regulatory mechanism by which MTHFR modulates the risk for hepatic malignancies.
Collapse
Affiliation(s)
- Ming-Tsung Wu
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; (M.-T.W.); (W.-T.Y.); (Y.-C.W.); (P.-M.C.); (J.-Y.L.)
- Department of Civil and Environmental Engineering, South Kensington Campus, Imperial College London, London SW7 2AZ, UK
| | - Wei-Ting Ye
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; (M.-T.W.); (W.-T.Y.); (Y.-C.W.); (P.-M.C.); (J.-Y.L.)
| | - Yi-Cheng Wang
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; (M.-T.W.); (W.-T.Y.); (Y.-C.W.); (P.-M.C.); (J.-Y.L.)
| | - Po-Ming Chen
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; (M.-T.W.); (W.-T.Y.); (Y.-C.W.); (P.-M.C.); (J.-Y.L.)
| | - Jun-You Liu
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; (M.-T.W.); (W.-T.Y.); (Y.-C.W.); (P.-M.C.); (J.-Y.L.)
| | - Chien-Kuo Tai
- Department of Biomedical Sciences, National Chung Cheng University, Chia-Yi 62102, Taiwan;
| | - Feng-Yao Tang
- Department of Nutrition, China Medical University, Taichung 40402, Taiwan;
| | - Jian-Rong Li
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung 40227, Taiwan; (J.-R.L.); (C.-C.L.)
| | - Chun-Chi Liu
- Institute of Genomics and Bioinformatics, National Chung Hsing University, Taichung 40227, Taiwan; (J.-R.L.); (C.-C.L.)
| | - En-Pei Isabel Chiang
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung 40227, Taiwan; (M.-T.W.); (W.-T.Y.); (Y.-C.W.); (P.-M.C.); (J.-Y.L.)
- Innovation and Development Center of Sustainable Agriculture (IDCSA), National Chung Hsing University, Taichung 40227, Taiwan
- Correspondence:
| |
Collapse
|
3
|
Petrone I, Bernardo PS, dos Santos EC, Abdelhay E. MTHFR C677T and A1298C Polymorphisms in Breast Cancer, Gliomas and Gastric Cancer: A Review. Genes (Basel) 2021; 12:587. [PMID: 33920562 PMCID: PMC8073588 DOI: 10.3390/genes12040587] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/08/2021] [Accepted: 04/15/2021] [Indexed: 02/07/2023] Open
Abstract
Folate (vitamin B9) is found in some water-soluble foods or as a synthetic form of folic acid and is involved in many essential biochemical processes. Dietary folate is converted into tetrahydrofolate, a vital methyl donor for most methylation reactions, including DNA methylation. 5,10-methylene tetrahydrofolate reductase (MTHFR) is a critical enzyme in the folate metabolism pathway that converts 5,10-methylenetetrahydrofolate into 5-methyltetrahydrofolate, which produces a methyl donor for the remethylation of homocysteine to methionine. MTHFR polymorphisms result in reduced enzyme activity and altered levels of DNA methylation and synthesis. MTHFR polymorphisms have been linked to increased risks of several pathologies, including cancer. Breast cancer, gliomas and gastric cancer are highly heterogeneous and aggressive diseases associated with high mortality rates. The impact of MTHFR polymorphisms on these tumors remains controversial in the literature. This review discusses the relationship between the MTHFR C677T and A1298C polymorphisms and the increased risk of breast cancer, gliomas, and gastric cancer. Additionally, we highlight the relevance of ethnic and dietary aspects of population-based studies and histological stratification of highly heterogeneous tumors. Finally, this review discusses these aspects as potential factors responsible for the controversial literature concerning MTHFR polymorphisms.
Collapse
Affiliation(s)
- Igor Petrone
- Stem Cell Laboratory, Center for Bone Marrow Transplants, Brazilian National Cancer Institute—INCA, Rio de Janeiro 20230-240, Brazil; (E.C.d.S.); (E.A.)
- Stricto Sensu Graduate Program in Oncology, INCA, Rio de Janeiro 20230-240, Brazil;
| | - Paula Sabbo Bernardo
- Stricto Sensu Graduate Program in Oncology, INCA, Rio de Janeiro 20230-240, Brazil;
- Laboratory of Cellular and Molecular Hemato-Oncology, Molecular Hemato-Oncology Program, Brazilian National Cancer Institute—INCA, Rio de Janeiro 20230-240, Brazil
| | - Everton Cruz dos Santos
- Stem Cell Laboratory, Center for Bone Marrow Transplants, Brazilian National Cancer Institute—INCA, Rio de Janeiro 20230-240, Brazil; (E.C.d.S.); (E.A.)
- Stricto Sensu Graduate Program in Oncology, INCA, Rio de Janeiro 20230-240, Brazil;
| | - Eliana Abdelhay
- Stem Cell Laboratory, Center for Bone Marrow Transplants, Brazilian National Cancer Institute—INCA, Rio de Janeiro 20230-240, Brazil; (E.C.d.S.); (E.A.)
- Stricto Sensu Graduate Program in Oncology, INCA, Rio de Janeiro 20230-240, Brazil;
| |
Collapse
|
4
|
Zawiah M, Yousef AM, Kadi T, Yousef M, Majdalawi K, Al-Yacoub S, Al-Hiary R, Tantawi D, Mukred R, Ajaj AR. Early disease relapse in a patient with colorectal cancer who harbors genetic variants of DPYD, TYMS, MTHFR and DHFR after treatment with 5-fluorouracil-based chemotherapy. Drug Metab Pers Ther 2018; 33:201-205. [PMID: 30207288 DOI: 10.1515/dmpt-2018-0012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/30/2018] [Indexed: 12/16/2022]
Abstract
Background Early relapse in colorectal cancer (CRC) after curative resection is mainly attributed to the key determinants such as tumor histology, stage, lymphovascular invasion, and the response to chemotherapy. Case presentation Interindividual variability in the efficacy of adjuvant chemotherapy between patients receiving the same treatment may be ascribed to the patients' genetic profile. In this report, we highlight a clinical case of a patient with stage II CRC who relapsed within a short period after starting adjuvant chemotherapy and was later found to have multiple genetic polymorphisms in the DPYD, TYMS, MTHFR, and DHFR genes. Conclusions Based on the clinical data of the patient and the key role of these genes in 5-fluorouracil pathway, we hypothesize that these variants may contribute to the drug response and early relapse in CRC.
Collapse
Affiliation(s)
- Mohammed Zawiah
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Al-Motassem Yousef
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Taha Kadi
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Mohammed Yousef
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Khalil Majdalawi
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Shorouq Al-Yacoub
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Rasha Al-Hiary
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Dua'a Tantawi
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | - Ramzi Mukred
- Department of Biopharmaceutics and Clinical Pharmacy, School of Pharmacy, The University of Jordan, Amman, Jordan
| | | |
Collapse
|
5
|
Field MS, Lan X, Stover DM, Stover PJ. Dietary Uridine Decreases Tumorigenesis in the ApcMin/+ Model of Intestinal Cancer. Curr Dev Nutr 2018; 2:nzy013. [PMID: 29955725 PMCID: PMC5998365 DOI: 10.1093/cdn/nzy013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/13/2018] [Accepted: 02/27/2018] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Dietary deoxyuridine and uridine have been shown to have opposing effects on neural tube defect (NTD) incidence in the serine hydroxymethyltransferase 1 (Shmt1+/- ) mouse model of folate-responsive NTDs, which are mediated by changes in de novo thymidylate biosynthesis. Alterations in folate-mediated one-carbon metabolism that protect against NTDs increased cancer risk in some studies. OBJECTIVE This study examined the effects of the dietary pyrimidine nucleosides uridine, thymidine, or deoxyuridine on intestinal tumorigenesis in the ApcMin/+ mouse model [a mouse model lacking one copy of the adenomatosis polypsis coli (APC) gene] of spontaneous intestinal tumor formation. This study also evaluated the effects of uridine and deoxyuridine in culture medium on antifolate efficacy in Caco-2 and HeLa cell lines. METHODS ApcMin/+ male mice (n = 10-14/group) were fed folate-deficient diets containing uridine, thymidine, or deoxyuridine from weaning until 17 wk of age. Total intestinal tumors were analyzed and biomarkers of folate status and metabolism were measured, including plasma folate concentrations, colon uracil content, and SHMT1 concentrations. RESULTS ApcMin/+ mice fed dietary uridine showed a 50% reduction in total intestinal tumors, but neither dietary deoxyuridine nor thymidine affected tumorigenesis. Dietary nucleoside supplementation also increased plasma folate concentrations in ApcMin/+ mice, as has been observed in the Shmt1+/- mouse model. Neither uridine nor deoxyuridine in culture media affected antifolate efficacy in either HeLa or Caco-2 cell lines. CONCLUSIONS Dietary uridine, which is teratogenic in mice, decreases intestinal tumor formation in the ApcMin/+ mouse model. Dietary uridine mimics the effect of the common methylene tetrahydrofolate reductase (MTHFR) C677T variant in protecting against colorectal cancer, while contributing to the risk of NTDs.
Collapse
Affiliation(s)
- Martha S Field
- Division of Nutritional Sciences, Cornell University, Ithaca, NY
| | - Xu Lan
- Division of Nutritional Sciences, Cornell University, Ithaca, NY
| | - Denise M Stover
- Division of Nutritional Sciences, Cornell University, Ithaca, NY
| | - Patrick J Stover
- Division of Nutritional Sciences, Cornell University, Ithaca, NY
- Graduate Field of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY
| |
Collapse
|
6
|
Miquel S, Champ C, Day J, Aarts E, Bahr BA, Bakker M, Bánáti D, Calabrese V, Cederholm T, Cryan J, Dye L, Farrimond JA, Korosi A, Layé S, Maudsley S, Milenkovic D, Mohajeri MH, Sijben J, Solomon A, Spencer JPE, Thuret S, Vanden Berghe W, Vauzour D, Vellas B, Wesnes K, Willatts P, Wittenberg R, Geurts L. Poor cognitive ageing: Vulnerabilities, mechanisms and the impact of nutritional interventions. Ageing Res Rev 2018; 42:40-55. [PMID: 29248758 DOI: 10.1016/j.arr.2017.12.004] [Citation(s) in RCA: 122] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/08/2017] [Accepted: 12/08/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Ageing is a highly complex process marked by a temporal cascade of events, which promote alterations in the normal functioning of an individual organism. The triggers of normal brain ageing are not well understood, even less so the factors which initiate and steer the neuronal degeneration, which underpin disorders such as dementia. A wealth of data on how nutrients and diets may support cognitive function and preserve brain health are available, yet the molecular mechanisms underlying their biological action in both normal ageing, age-related cognitive decline, and in the development of neurodegenerative disorders have not been clearly elucidated. OBJECTIVES This review aims to summarise the current state of knowledge of vulnerabilities that predispose towards dysfunctional brain ageing, highlight potential protective mechanisms, and discuss dietary interventions that may be used as therapies. A special focus of this paper is on the impact of nutrition on neuroprotection and the underlying molecular mechanisms, and this focus reflects the discussions held during the 2nd workshop 'Nutrition for the Ageing Brain: Functional Aspects and Mechanisms' in Copenhagen in June 2016. The present review is the most recent in a series produced by the Nutrition and Mental Performance Task Force under the auspice of the International Life Sciences Institute Europe (ILSI Europe). CONCLUSION Coupling studies of cognitive ageing with studies investigating the effect of nutrition and dietary interventions as strategies targeting specific mechanisms, such as neurogenesis, protein clearance, inflammation, and non-coding and microRNAs is of high value. Future research on the impact of nutrition on cognitive ageing will need to adopt a longitudinal approach and multimodal nutritional interventions will likely need to be imposed in early-life to observe significant impact in older age.
Collapse
Affiliation(s)
- Sophie Miquel
- Mars-Wrigley, 1132 W. Blackhawk Street, Chicago, IL 60642, United States
| | - Claire Champ
- Human Appetite Research Unit, School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Jon Day
- Cerebrus Associates Limited, The White House, 2 Meadrow, Godalming, Surrey, GU7 3HN, United Kingdom
| | - Esther Aarts
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen, Kapittelweg 29, 6525 EN Nijmegen, The Netherlands
| | - Ben A Bahr
- Biotechnology Research and Training Centre, University of North Carolina - Pembroke, United States
| | - Martijntje Bakker
- The Netherlands Organisation for Health Research and Development, Laan van Nieuw Oost-Indië 334, 2593 CE The Hague, The Netherlands
| | - Diána Bánáti
- International Life Sciences Institute, Europe (ILSI Europe), Av E. Mounier 83, Box 6, 1200 Brussels, Belgium
| | - Vittorio Calabrese
- University of Catania, Department of Biomedical and Biotechnological Sciences, Biological Tower - Via Santa Sofia, 97, Catania, Italy
| | - Tommy Cederholm
- University of Uppsala, Institutionen för folkhälso- och vårdvetenskap, Klinisk nutrition och metabolism, Uppsala Science Park, 751 85 Uppsala, Sweden
| | - John Cryan
- Anatomy & Neuroscience, University College Cork, 386 Western Gateway Building, Cork, Ireland
| | - Louise Dye
- Human Appetite Research Unit, School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | | | - Aniko Korosi
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Sophie Layé
- Nutrition et Neurobiologie Intégrée, INRA Bordeaux University, 146 rue Léo Saignat, 33076 Bordeaux cedex, France
| | - Stuart Maudsley
- Department of Biomedical Research and VIB-UAntwerp Center for Molecular Neurology, University of Antwerp, Gebouw V, Campus Drie Eiken, Universiteitsplein 1, 2610 Antwerpen, Belgium
| | - Dragan Milenkovic
- INRA, Human Nutrition Unit, UCA, F-63003, Clermont-Ferrand, France; Department of Internal Medicine, Division of Cardiovascular Medicine, School of Medicine, University of California Davis, Davis, CA 95616, United States
| | - M Hasan Mohajeri
- DSM Nutritional Products Ltd., Wurmisweg 576, Kaiseraugst 4303, Switzerland
| | - John Sijben
- Nutricia Research, Nutricia Advanced Medical Nutrition, PO Box 80141, 3508TC, Utrecht, The Netherlands
| | - Alina Solomon
- Aging Research Center, Karolinska Institutet, Gävlegatan 16, SE-113 30 Stockholm, Sweden
| | - Jeremy P E Spencer
- Hugh Sinclair Unit of Human Nutrition and Institute for Cardiovascular and Metabolic Research, Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading, RG6 6AP, United Kingdom
| | - Sandrine Thuret
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, The Maurice Wohl Clinical Neuroscience Institute,125 Coldharbour Lane, SE5 9NU London, United Kingdom
| | - Wim Vanden Berghe
- PPES, Department Biomedical Sciences, University Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Antwerp, Belgium
| | - David Vauzour
- University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Bruno Vellas
- Department of Geriatric Medicine, CHU Toulouse, Gerontopole, Toulouse, France
| | - Keith Wesnes
- Wesnes Cognition Limited, Little Paddock, Streatley on Thames, RG8 9RD, United Kingdom; Medical School, University of Exeter, Exeter, United Kingdom; Department of Psychology, Northumbria University, Newcastle, United Kingdom; Centre for Human Psychopharmacology, Swinburne University, Melbourne, Australia; Medicinal Plant Research Group, Newcastle University, United Kingdom
| | - Peter Willatts
- School of Psychology, University of Dundee Nethergate, Dundee, DD1 4HN, United Kingdom
| | - Raphael Wittenberg
- London School of Economics and Political Science, Personal Social Services Research Unit, London, United Kingdom
| | - Lucie Geurts
- International Life Sciences Institute, Europe (ILSI Europe), Av E. Mounier 83, Box 6, 1200 Brussels, Belgium.
| |
Collapse
|
7
|
Nithya K, Isabel W, Angeline T, Priscilla A, Shakila H, Asirvatham A. MTHFR C677T gene polymorphism in Type 2 diabetes mellitus patients with and without vascular complications: A case-control study. Meta Gene 2017. [DOI: 10.1016/j.mgene.2017.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
8
|
Identifying novel genes and biological processes relevant to the development of cancer therapy-induced mucositis: An informative gene network analysis. PLoS One 2017; 12:e0180396. [PMID: 28678827 PMCID: PMC5498049 DOI: 10.1371/journal.pone.0180396] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 05/30/2017] [Indexed: 12/20/2022] Open
Abstract
Mucositis is a complex, dose-limiting toxicity of chemotherapy or radiotherapy that leads to painful mouth ulcers, difficulty eating or swallowing, gastrointestinal distress, and reduced quality of life for patients with cancer. Mucositis is most common for those undergoing high-dose chemotherapy and hematopoietic stem cell transplantation and for those being treated for malignancies of the head and neck. Treatment and management of mucositis remain challenging. It is expected that multiple genes are involved in the formation, severity, and persistence of mucositis. We used Ingenuity Pathway Analysis (IPA), a novel network-based approach that integrates complex intracellular and intercellular interactions involved in diseases, to systematically explore the molecular complexity of mucositis. As a first step, we searched the literature to identify genes that harbor or are close to the genetic variants significantly associated with mucositis. Our literature review identified 27 candidate genes, of which ERCC1, XRCC1, and MTHFR were the most frequently studied for mucositis. On the basis of this 27-gene list, we used IPA to generate gene networks for mucositis. The most biologically significant novel molecules identified through IPA analyses included TP53, CTNNB1, MYC, RB1, P38 MAPK, and EP300. Additionally, uracil degradation II (reductive) and thymine degradation pathways (p = 1.06-08) were most significant. Finally, utilizing 66 SNPs within the 8 most connected IPA-derived candidate molecules, we conducted a genetic association study for oral mucositis in the head and neck cancer patients who were treated using chemotherapy and/or radiation therapy (186 head and neck cancer patients with oral mucositis vs. 699 head and neck cancer patients without oral mucositis). The top ranked gene identified through this association analysis was RB1 (rs2227311, p-value = 0.034, odds ratio = 0.67). In conclusion, gene network analysis identified novel molecules and biological processes, including pathways related to inflammation and oxidative stress, that are relevant to mucositis development, thus providing the basis for future studies to improve the management and treatment of mucositis in patients with cancer.
Collapse
|
9
|
Misselbeck K, Marchetti L, Field MS, Scotti M, Priami C, Stover PJ. A hybrid stochastic model of folate-mediated one-carbon metabolism: Effect of the common C677T MTHFR variant on de novo thymidylate biosynthesis. Sci Rep 2017; 7:797. [PMID: 28400561 PMCID: PMC5429759 DOI: 10.1038/s41598-017-00854-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/13/2017] [Indexed: 11/19/2022] Open
Abstract
Folate-mediated one-carbon metabolism (FOCM) is an interconnected network of metabolic pathways, including those required for the de novo synthesis of dTMP and purine nucleotides and for remethylation of homocysteine to methionine. Mouse models of folate-responsive neural tube defects (NTDs) indicate that impaired de novo thymidylate (dTMP) synthesis through changes in SHMT expression is causative in folate-responsive NTDs. We have created a hybrid computational model comprised of ordinary differential equations and stochastic simulation. We investigated whether the de novo dTMP synthesis pathway was sensitive to perturbations in FOCM that are known to be associated with human NTDs. This computational model shows that de novo dTMP synthesis is highly sensitive to the common MTHFR C677T polymorphism and that the effect of the polymorphism on FOCM is greater in folate deficiency. Computational simulations indicate that the MTHFR C677T polymorphism and folate deficiency interact to increase the stochastic behavior of the FOCM network, with the greatest instability observed for reactions catalyzed by serine hydroxymethyltransferase (SHMT). Furthermore, we show that de novo dTMP synthesis does not occur in the cytosol at rates sufficient for DNA replication, supporting empirical data indicating that impaired nuclear de novo dTMP synthesis results in uracil misincorporation into DNA.
Collapse
Affiliation(s)
- Karla Misselbeck
- The Microsoft Research - University of Trento Centre for Computational and Systems Biology (COSBI), Piazza Manifattura, 1, 38068, Rovereto (TN), Italy
- Department of Mathematics, University of Trento, Trento, Italy
| | - Luca Marchetti
- The Microsoft Research - University of Trento Centre for Computational and Systems Biology (COSBI), Piazza Manifattura, 1, 38068, Rovereto (TN), Italy
| | - Martha S Field
- Division of Nutritional Sciences, Cornell University, Ithaca, New York, 14853, USA
| | - Marco Scotti
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany
| | - Corrado Priami
- The Microsoft Research - University of Trento Centre for Computational and Systems Biology (COSBI), Piazza Manifattura, 1, 38068, Rovereto (TN), Italy.
- Department of Mathematics, University of Trento, Trento, Italy.
| | - Patrick J Stover
- Division of Nutritional Sciences, Cornell University, Ithaca, New York, 14853, USA.
| |
Collapse
|
10
|
Zhang B, Zhang W, Yan L, Wang D. The association between MTHFR gene C677T polymorphism and ALL risk based on a meta-analysis involving 17,469 subjects. Clin Chim Acta 2017; 466:85-92. [DOI: 10.1016/j.cca.2017.01.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2016] [Revised: 01/01/2017] [Accepted: 01/02/2017] [Indexed: 12/29/2022]
|
11
|
Tsang BL, Devine OJ, Cordero AM, Marchetta CM, Mulinare J, Mersereau P, Guo J, Qi YP, Berry RJ, Rosenthal J, Crider KS, Hamner HC. Assessing the association between the methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism and blood folate concentrations: a systematic review and meta-analysis of trials and observational studies. Am J Clin Nutr 2015; 101:1286-94. [PMID: 25788000 DOI: 10.3945/ajcn.114.099994] [Citation(s) in RCA: 85] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 02/09/2015] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND The methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism is a risk factor for neural tube defects. The T allele produces an enzyme with reduced folate-processing capacity, which has been associated with lower blood folate concentrations. OBJECTIVE We assessed the association between MTHFR C677T genotypes and blood folate concentrations among healthy women aged 12-49 y. DESIGN We conducted a systematic review of the literature published from January 1992 to March 2014 to identify trials and observational studies that reported serum, plasma, or red blood cell (RBC) folate concentrations and MTHFR C677T genotype. We conducted a meta-analysis for estimates of percentage differences in blood folate concentrations between genotypes. RESULTS Forty studies met the inclusion criteria. Of the 6 studies that used the microbiologic assay (MA) to measure serum or plasma (S/P) and RBC folate concentrations, the percentage difference between genotypes showed a clear pattern of CC > CT > TT. The percentage difference was greatest for CC > TT [S/P: 13%; 95% credible interval (CrI): 7%, 18%; RBC: 16%; 95% CrI: 12%, 20%] followed by CC > CT (S/P: 7%; 95% CrI: 1%, 12%; RBC: 8%; 95% CrI: 4%, 12%) and CT > TT (S/P: 6%; 95% CrI: 1%, 11%; RBC: 9%; 95% CrI: 5%, 13%). S/P folate concentrations measured by using protein-binding assays (PBAs) also showed this pattern but to a greater extent (e.g., CC > TT: 20%; 95% CrI: 17%, 22%). In contrast, RBC folate concentrations measured by using PBAs did not show the same pattern and are presented in the Supplemental Material only. CONCLUSIONS Meta-analysis results (limited to the MA, the recommended population assessment method) indicated a consistent percentage difference in S/P and RBC folate concentrations across MTHFR C677T genotypes. Lower blood folate concentrations associated with this polymorphism could have implications for a population-level risk of neural tube defects.
Collapse
Affiliation(s)
- Becky L Tsang
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Owen J Devine
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Amy M Cordero
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Claire M Marchetta
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Joseph Mulinare
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Patricia Mersereau
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Jing Guo
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Yan Ping Qi
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Robert J Berry
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Jorge Rosenthal
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Krista S Crider
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM)
| | - Heather C Hamner
- From the Division of Birth Defects and Developmental Disabilities, National Center for Birth Defects and Developmental Disabilities (NCBDDD), CDC, Atlanta, GA (AMC, RJB, JR, and KSC); the Division of Nutrition, Physical Activity, and Obesity, National Center on Chronic Disease Prevention and Health Promotion, CDC, Atlanta, GA (HCH); Acentia (contractor for CDC, NCBDDD), Falls Church, VA (JG); Carter Consulting Inc. (contractor for CDC, NCBDDD), Atlanta, GA (OJD, JM, and YPQ); the Oak Ridge Institute for Science and Education, Oak Ridge, TN (BLT, CMM, and YPQ); SciMetrika LLC (contractor for CDC, NCBDDD), Atlanta, GA (PM).
| |
Collapse
|
12
|
Bellampalli R, Phani NM, Bhat KG, Prasad K, Bhaskaranand N, Guruprasad KP, Rai PS, Satyamoorthy K. Significance of 5,10-methylenetetrahydrofolate reductase gene variants in acute lymphoblastic leukemia in Indian population: an experimental, computational and meta-analysis. Leuk Lymphoma 2014; 56:1450-9. [DOI: 10.3109/10428194.2014.953154] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
13
|
Wlodarczyk BJ, Zhu H, Finnell RH. Mthfr gene ablation enhances susceptibility to arsenic prenatal toxicity. Toxicol Appl Pharmacol 2013; 275:22-7. [PMID: 24384392 DOI: 10.1016/j.taap.2013.12.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Revised: 12/03/2013] [Accepted: 12/18/2013] [Indexed: 11/27/2022]
Abstract
BACKGROUND In utero exposure to arsenic is known to adversely affect reproductive outcomes. Evidence of arsenic teratogenicity varies widely and depends on individual genotypic differences in sensitivity to As. In this study, we investigated the potential interaction between 5,10-methylenetetrahydrofolate reductase (Mthfr) genotype and arsenic embryotoxicity using the Mthfr knockout mouse model. METHODS Pregnant dams were treated with sodium arsenate, and reproductive outcomes including: implantation, resorption, congenital malformation and fetal birth weight were recorded at E18.5. RESULTS When the dams in Mthfr(+/-)×Mthfr(+/-) matings were treated with 7.2 mg/kg As, the resorption rate increased to 43.4%, from a background frequency of 7.2%. The As treatment also induced external malformations (40.9%) and significantly lowered the average fetal birth weight among fetuses, without any obvious toxic effect on the dam. When comparing the pregnancy outcomes resulting from different mating scenarios (Mthfr(+/+)×Mthfr(+/-), Mthfr(+/-)×Mthfr(+/-) and Mthfr(-/-)×(Mthfr+/-)) and arsenic exposure; the resorption rate showed a linear relationship with the number of null alleles (0, 1 or 2) in the Mthfr dams. Fetuses from nullizygous dams had the highest rate of external malformations (43%) and lowest average birth weight. When comparing the outcomes of reciprocal matings (nullizygote×wild-type versus wild-type×nullizygote) after As treatment, the null dams showed significantly higher rates of resorptions and malformations, along with lower fetal birth weights. CONCLUSIONS Maternal genotype contributes to the sensitivity of As embryotoxicity in the Mthfr mouse model. The fetal genotype, however, does not appear to affect the reproductive outcome after in utero As exposure.
Collapse
Affiliation(s)
- Bogdan J Wlodarczyk
- Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 West Holcombe Blvd., Houston, TX 77030, USA.
| | - Huiping Zhu
- Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 West Holcombe Blvd., Houston, TX 77030, USA
| | - Richard H Finnell
- Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 West Holcombe Blvd., Houston, TX 77030, USA
| |
Collapse
|
14
|
Kuo CS, Huang CY, Kuo HT, Cheng CP, Chen CH, Lu CL, Yang FL, Syu Huang RF. Interrelationships among genetic C677T polymorphism of 5,10-methylenetetrahydrofolate reductase, biochemical folate status, and lymphocytic p53 oxidative damage in association with tumor malignancy and survivals of patients with hepatocellular carcinoma. Mol Nutr Food Res 2013; 58:329-42. [PMID: 23996892 DOI: 10.1002/mnfr.201200479] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 06/20/2013] [Accepted: 06/21/2013] [Indexed: 12/13/2022]
Abstract
SCOPE Metabolic genotypes of 5,10-methylenetetrahydrofolate reductase (MTHFR) and folate status on oxidative DNA lesions in hepatocellular carcinoma (HCC) has not been elucidated. The aims of the study were to investigate the folate-polymorphic interactions on genetic oxidative damage in association with advanced HCC malignancy and prognosis. METHODS AND RESULTS The study included 232 HCC patients with folate nutrition, MTHFR C677T polymorphic, p53 genetic and tumour pathological data collected and analyzed for their survivals after a 7.8-years following up. By adjustment for oxidative risk factors of HCC, the compound CT and TT genotypes in relative to the CC wild-type were associated with 83% reduced lymphocytic p53 oxidative lesions of HCC patients with RBC folate lower than 688 ng/mL (OR: 0.17, 95%CI: 0.07-0.43). Such genetic protective effects by the CT/TT genotypes were 2-fold enhanced among those with high RBC folate (OR: 0.08, 95% CI: 0.03-0.21, P for interaction < 0.001). For those with non-folate-deficient status, the compound CT and TT vs. CC genotypes were associated with 80% reduced risks of advanced HCC stages (III&IV) (OR: 0.2, 95%CI: 0.08-0.56). Such protection was negated either by adjustment of lymphocytic p53 oxidative lesions or by 3-fold increased risks among those with high RBC status (OR: 0.6, 95%CI; 0.31-1.41, P for interaction = 0.009). Multivariate Cox proportional hazards analysis showed that the CT/TT genotypes vs. CC wild-type were the independent predictable factor for better survival outcome of HCC patients (HR: 0.48, CI = 0.30-0.79). For CC homozygote, the second vs. the bottom tertile levels of RBC status were associated with 2-fold increased mortality rate of HCC patients (HR: 2.05, CI = 1.0-4.1). CONCLUSION Our data demonstrated that reduced MTHFR activities associated with the MTHFR T allele may interact with RBC folate as the risk modifiers of lymphocytic p53 oxidative lesions of HCC patients. The CT/TT genotypes correlated with lower risks of late-stage HCC and a favorable survival of HCC patients, depending on p53 oxidative lesions or RBC folate status.
Collapse
Affiliation(s)
- Chang-Sheng Kuo
- Ph.D. Program in Nutrition and Food Science, Fu Jen Catholic University, HsinChuang, Taiwan
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Quinlivan EP, Crider KS, Zhu JH, Maneval DR, Hao L, Li Z, Rasmussen SA, Berry RJ, Bailey LB. Hypomethylation of serum blood clot DNA, but not plasma EDTA-blood cell pellet DNA, from vitamin B12-deficient subjects. PLoS One 2013; 8:e65241. [PMID: 23785415 PMCID: PMC3681792 DOI: 10.1371/journal.pone.0065241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 04/22/2013] [Indexed: 12/20/2022] Open
Abstract
Vitamin B12, a co-factor in methyl-group transfer, is important in maintaining DNA (deoxycytidine) methylation. Using two independent assays we examined the effect of vitamin B12-deficiency (plasma vitamin B12<148 pmol/L) on DNA methylation in women of childbearing age. Coagulated blood clot DNA from vitamin B12-deficient women had significantly (p<0.001) lower percentage deoxycytidine methylation (3.23±0.66%; n = 248) and greater [3 H]methyl-acceptance (42,859±9,699 cpm; n = 17) than DNA from B12-replete women (4.44±0.18%; n = 128 and 26,049±2,814 cpm; n = 11) [correlation between assays: r = -0.8538; p<0.001; n = 28]. In contrast, uncoagulated EDTA-blood cell pellet DNA from vitamin B12-deficient and B12-replete women exhibited similar percentage methylation (4.45±0.15%; n = 77 vs. 4.47±0.15%; n = 47) and [3 H]methyl-acceptance (27,378±4,094 cpm; n = 17 vs. 26,610±2,292 cpm; n = 11). Therefore, in simultaneously collected paired blood samples, vitamin B12-deficiency was associated with decreased DNA methylation only in coagulated samples. These findings highlight the importance of sample collection methods in epigenetic studies, and the potential impact biological processes can have on DNA methylation during collection.
Collapse
Affiliation(s)
- Eoin P Quinlivan
- Biomedical Mass Spectrometry Laboratory, Clinical and Translational Science Institute, University of Florida, Gainesville, Florida, United States of America.
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Wu XY, Ni J, Xu WJ, Zhou T, Wang X. Interactions between MTHFR C677T-A1298C variants and folic acid deficiency affect breast cancer risk in a Chinese population. Asian Pac J Cancer Prev 2013; 13:2199-206. [PMID: 22901194 DOI: 10.7314/apjcp.2012.13.5.2199] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Our objective was to evaluate the MTHFR C677T-A1298C polymorphisms in patients with breast cancer and in individuals with no history of cancer, to compare the levels of genetic damage and apoptosis under folic acid (FA) deficiency between patients and controls, and to assess associations with breast cancer. METHODS Genetic damage was marked by micronucleated binucleated cells (MNBN) and apoptosis was estimated by cytokinesis-block micronucleus assay (CBMN). PCR-RFLP molecular analysis was carried out. RESULTS The results showed significant associations between the MTHFR 677TT or the combined MTHFR C677T-A1298C and breast cancer risk (OR=2.51, CI=0.85 to 7.37, p=0.08; OR=4.11, CI=0.78 to 21.8, p<0.001). The MNBN from the combined MTHFR C677T-A1298C was higher and the apoptosis was lower than that of the single variants (p<0.05). At 15 to 60 nmol /L FA, the MNBN in cases with the TTAC genotype was higher than controls (p<0.05), whereas no significant difference in apoptosis was found between the cases and controls after excluding the genetic background. CONCLUSIONS Associations between the combined MTHFR C677T-A1298C polymorphism and breast cancer are possible from this study. A dose of 120 nmol/L FA could enhance apoptosis in cases with MTHFR C677T-A1298C. Breast cancer individuals with the TTAC genotype may be more sensitive to the genotoxic effects of FA deficiency than controls.
Collapse
Affiliation(s)
- Xia-Yu Wu
- School of Life Sciences, Yunnan University, Kunming, China
| | | | | | | | | |
Collapse
|
17
|
Abstract
SIGNIFICANCE The progressive, dose-dependent, and potentially reversible epigenetic changes observed in cancer present new opportunities in cancer risk modification and prevention using dietary and lifestyle factors. Folate, a water-soluble B vitamin, has been of intense interest because of an inverse association between folate status and the risk of several malignancies (particularly colorectal cancer) and its potential to modulate DNA methylation. Aberrant patterns and dysregulation of DNA methylation are mechanistically related to carcinogenesis. RECENT ADVANCES The effects of folate on DNA methylation patterns have recently been investigated in two important life stages: pre- and early postnatal life and aging. Recent studies have demonstrated that folate exposure in the intrauterine environment and early life and during the aging process may have profound effects on DNA methylation with significant functional ramifications, including the risk of cancer. CRITICAL ISSUES Evidence from animal, human, and in vitro studies suggest that the epigenetic effects of folate on DNA methylation are highly complex. The effects are gene and site specific and appear to depend on cell type, target organ, stage of transformation, the degree and duration of folate manipulations, interactions with other methyl group donors and dietary factors, and genetic variants in the folate metabolic pathways. FUTURE DIRECTIONS The potential for folate to modulate DNA methylation and, thus, modify the risk of cancer in humans is worthy of further investigation. Due to the complex relationship between folate exposure and DNA methylation, more elaborate epidemiological, clinical, and mechanistic studies that determine the clinical, biological, and molecular effects of folate are warranted.
Collapse
Affiliation(s)
- Anna Ly
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
18
|
Folate and Alzheimer: when time matters. J Neural Transm (Vienna) 2012; 120:211-24. [DOI: 10.1007/s00702-012-0822-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 05/06/2012] [Indexed: 12/14/2022]
|
19
|
Liu J, Hesson LB, Meagher AP, Bourke MJ, Hawkins NJ, Rand KN, Molloy PL, Pimanda JE, Ward RL. Relative distribution of folate species is associated with global DNA methylation in human colorectal mucosa. Cancer Prev Res (Phila) 2012; 5:921-9. [PMID: 22609762 DOI: 10.1158/1940-6207.capr-11-0577] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Folate exists as functionally diverse species within cells. Although folate deficiency may contribute to DNA hypomethylation in colorectal cancer, findings on the association between total folate concentration and global DNA methylation have been inconsistent. This study determined global, LINE-1, and Alu DNA methylation in blood and colon of healthy and colorectal cancer patients and their relationship to folate distribution. Blood and normal mucosa from 112 colorectal cancer patients and 114 healthy people were analyzed for global DNA methylation and folate species distribution using liquid chromatography tandem mass spectrometry. Repeat element methylation was determined using end-specific PCR. Colorectal mucosa had lower global and repeat element DNA methylation compared with peripheral blood (P < 0.0001). After adjusting for age, sex and smoking history, global but not repeat element methylation was marginally higher in normal mucosa from colorectal cancer patients compared with healthy individuals. Colorectal mucosa from colorectal cancer subjects had lower 5-methyltetrahydrofolate and higher tetrahydrofolate and formyltetrahydrofolate levels than blood from the same individual. Blood folate levels should not be used as a surrogate for the levels in colorectal mucosa because there are marked differences in folate species distribution between the two tissues. Similarly, repeat element methylation is not a good surrogate measure of global DNA methylation in both blood and colonic mucosa. There was no evidence that mucosal global DNA methylation or folate distribution was related to the presence of cancer per se, suggesting that if abnormalities exist, they are confined to individual cells rather than the entire colon.
Collapse
Affiliation(s)
- Jia Liu
- Lowy Cancer Research Centre and Prince of Wales Clinical School, Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Crider KS, Yang TP, Berry RJ, Bailey LB. Folate and DNA methylation: a review of molecular mechanisms and the evidence for folate's role. Adv Nutr 2012; 3:21-38. [PMID: 22332098 PMCID: PMC3262611 DOI: 10.3945/an.111.000992] [Citation(s) in RCA: 587] [Impact Index Per Article: 48.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
DNA methylation is an epigenetic modification critical to normal genome regulation and development. The vitamin folate is a key source of the one carbon group used to methylate DNA. Because normal mammalian development is dependent on DNA methylation, there is enormous interest in assessing the potential for changes in folate intake to modulate DNA methylation both as a biomarker for folate status and as a mechanistic link to developmental disorders and chronic diseases including cancer. This review highlights the role of DNA methylation in normal genome function, how it can be altered, and the evidence of the role of folate/folic acid in these processes.
Collapse
Affiliation(s)
- Krista S Crider
- Division of Birth Defects and Developmental Disabilities, National Center on Birth Defects and Developmental Disabilities, Atlanta, GA, USA.
| | | | | | | |
Collapse
|
21
|
Crider KS, Quinlivan EP, Berry RJ, Hao L, Li Z, Maneval D, Yang TP, Rasmussen SA, Yang Q, Zhu JH, Hu DJ, Bailey LB. Genomic DNA methylation changes in response to folic acid supplementation in a population-based intervention study among women of reproductive age. PLoS One 2011; 6:e28144. [PMID: 22163281 PMCID: PMC3233549 DOI: 10.1371/journal.pone.0028144] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 11/02/2011] [Indexed: 12/02/2022] Open
Abstract
Folate is a source of one-carbons necessary for DNA methylation, a critical epigenetic modification necessary for genomic structure and function. The use of supplemental folic acid is widespread however; the potential influence on DNA methylation is unclear. We measured global DNA methylation using DNA extracted from samples from a population-based, double-blind randomized trial of folic acid supplementation (100, 400, 4000 µg per day) taken for 6 months; including a 3 month post-supplementation sample. We observed no changes in global DNA methylation in response to up to 4,000 µg/day for 6 months supplementation in DNA extracted from uncoagulated blood (approximates circulating blood). However, when DNA methylation was determined in coagulated samples from the same individuals at the same time, significant time, dose, and MTHFR genotype-dependent changes were observed. The baseline level of DNA methylation was the same for uncoagulated and coagulated samples; marked differences between sample types were observed only after intervention. In DNA from coagulated blood, DNA methylation decreased (−14%; P<0.001) after 1 month of supplementation and 3 months after supplement withdrawal, methylation decreased an additional 23% (P<0.001) with significant variation among individuals (max+17%; min-94%). Decreases in methylation of ≥25% (vs. <25%) after discontinuation of supplementation were strongly associated with genotype: MTHFR CC vs. TT (adjusted odds ratio [aOR] 12.9, 95%CI 6.4, 26.0). The unexpected difference in DNA methylation between DNA extracted from coagulated and uncoagulated samples in response to folic acid supplementation is an important finding for evaluating use of folic acid and investigating the potential effects of folic acid supplementation on coagulation.
Collapse
Affiliation(s)
- Krista S Crider
- Division of Birth Defects and Developmental Disabilities, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
Abstract
The role of metabolic compartmentation in spatially organizing metabolic enzymes into pathways, regulating flux through metabolic pathways, and controlling the partitioning of metabolic intermediates among pathways is appreciated, but our understanding of the mechanisms that establish metabolic architecture and mediate communication and regulation among interconnected metabolic pathways and networks is still incomplete. This review discusses recent advancements in our understanding of metabolic compartmentation within the pathways that constitute the folate-mediated one-carbon metabolic network and emerging evidence for a need to regulate the trafficking of folates among compartmentalized metabolic pathways.
Collapse
|
23
|
Lamers Y, Coats B, Ralat M, Quinlivan EP, Stacpoole PW, Gregory JF. Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women. J Nutr 2011; 141:835-42. [PMID: 21430249 PMCID: PMC3077887 DOI: 10.3945/jn.110.134197] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Methionine is the precursor for S-adenosylmethionine (SAM), the major 1-carbon donor involved in >100 transmethylation reactions. Homocysteine produced from SAM must be metabolized either by remethylation for recycling of methionine or transsulfuration to form cystathionine and then cysteine. Pyridoxal 5'-phosphate (PLP) serves as a coenzyme in enzymes involved in transsulfuration as well as for primary acquisition of 1-carbon units used for remethylation and other phases of 1-carbon metabolism. Because the intake of vitamin B-6 is frequently low in humans and metabolic consequences of inadequacy may be amplified in the postprandial state, we aimed to determine the effects of marginal vitamin B-6 deficiency on the postprandial rates of remethylation, transmethylation, overall transsulfuration, and cystathionine synthesis. Healthy, young adults (4 male, 5 female; 20-35 y) received a primed, constant infusion of [1-(13)C]methionine, [methyl-(2)H(3)]methionine, and [5,5,5-(2)H(3)]leucine to quantify in vivo kinetics at normal vitamin B-6 status and after a 28-d dietary vitamin B-6 restriction. Vitamin B-6 restriction lowered the plasma PLP concentration from 49 ± 4 nmol/L (mean ± SEM) to 19 ± 2 nmol/L (P < 0.0001). Mean remethylation, transsulfuration, and transmethylation rates did not change in response to vitamin B-6 restriction; however, the responses to vitamin B-6 restriction varied greatly among individuals. The plasma cystathionine concentration increased from 142 ± 8 to 236 ± 9 nmol/L (P < 0.001), whereas the fractional cystathionine synthesis rate increased by a mean of 12% in 8 of 9 participants. Interrelationships among plasma concentrations of glycine and cystathionine and kinetic results suggest that individual variability occurs in normal postprandial 1-carbon metabolism and in the response to vitamin B-6 restriction.
Collapse
Affiliation(s)
- Yvonne Lamers
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, College of Medicine, University of Florida, Gainesville, FL 32611-0370
| | - Bonnie Coats
- Division of Endocrinology and Metabolism, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL 32611-0370
| | - Maria Ralat
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, College of Medicine, University of Florida, Gainesville, FL 32611-0370
| | - Eoin P. Quinlivan
- Division of Endocrinology and Metabolism, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL 32611-0370
| | - Peter W. Stacpoole
- Division of Endocrinology and Metabolism, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL 32611-0370,Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611-0370
| | - Jesse F. Gregory
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, College of Medicine, University of Florida, Gainesville, FL 32611-0370,To whom correspondence should be addressed. E-mail:
| |
Collapse
|
24
|
Duthie SJ. Folate and cancer: how DNA damage, repair and methylation impact on colon carcinogenesis. J Inherit Metab Dis 2011; 34:101-9. [PMID: 20544289 DOI: 10.1007/s10545-010-9128-0] [Citation(s) in RCA: 177] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Revised: 02/24/2010] [Accepted: 05/05/2010] [Indexed: 12/18/2022]
Abstract
Inappropriate diet may contribute to one third of cancer deaths. Folates, a group of water-soluble B vitamins present in high concentrations in green, leafy vegetables, maintain DNA stability through their ability to donate one-carbon units for cellular metabolism. Folate deficiency has been implicated in the development of several cancers, including cancer of the colorectum, breast, ovary, pancreas, brain, lung and cervix. Generally, data from the majority of human studies suggest that people who habitually consume the highest level of folate, or with the highest blood folate concentrations, have a significantly reduced risk of developing colon polyps or cancer. However, an entirely protective role for folate against carcinogenesis has been questioned, and recent data indicate that an excessive intake of synthetic folic acid (from high-dose supplements or fortified foods) may increase human cancers by accelerating growth of precancerous lesions. Nonetheless, on balance, evidence from the majority of human studies indicates that dietary folate is genoprotective against colon cancer. Suboptimal folate status in humans is widespread. Folate maintains genomic stability by regulating DNA biosynthesis, repair and methylation. Folate deficiency induces and accelerates carcinogenesis by perturbing each of these processes. This review presents recent evidence describing how these mechanisms act, and interact, to modify colon cancer risk.
Collapse
Affiliation(s)
- Susan J Duthie
- Nutrition and Epigenetics Group, Division of Vascular Health, Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen, UK.
| |
Collapse
|
25
|
Bolusani S, Young BA, Cole NA, Tibbetts AS, Momb J, Bryant JD, Solmonson A, Appling DR. Mammalian MTHFD2L encodes a mitochondrial methylenetetrahydrofolate dehydrogenase isozyme expressed in adult tissues. J Biol Chem 2010; 286:5166-74. [PMID: 21163947 DOI: 10.1074/jbc.m110.196840] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previous studies in our laboratory showed that isolated, intact adult rat liver mitochondria are able to oxidize the 3-carbon of serine and the N-methyl carbon of sarcosine to formate without the addition of any other cofactors or substrates. Conversion of these 1-carbon units to formate requires several folate-interconverting enzymes in mitochondria. The enzyme(s) responsible for conversion of 5,10-methylene-tetrahydrofolate (CH(2)-THF) to 10-formyl-THF in adult mammalian mitochondria are currently unknown. A new mitochondrial CH(2)-THF dehydrogenase isozyme, encoded by the MTHFD2L gene, has now been identified. The recombinant protein exhibits robust NADP(+)-dependent CH(2)-THF dehydrogenase activity when expressed in yeast. The enzyme is localized to mitochondria when expressed in CHO cells and behaves as a peripheral membrane protein, tightly associated with the matrix side of the mitochondrial inner membrane. The MTHFD2L gene is subject to alternative splicing and is expressed in adult tissues in humans and rodents. This CH(2)-THF dehydrogenase isozyme thus fills the remaining gap in the pathway from CH(2)-THF to formate in adult mammalian mitochondria.
Collapse
Affiliation(s)
- Swetha Bolusani
- Department of Chemistry and Biochemistry and the Institute for Cellular and Molecular Biology, The University of Texas, Austin, Texas 78712, USA
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Folate and One-Carbon Metabolism and Its Impact on Aberrant DNA Methylation in Cancer. EPIGENETICS AND CANCER, PART B 2010; 71:79-121. [DOI: 10.1016/b978-0-12-380864-6.00004-3] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
|
27
|
Abstract
Impairments in folate-mediated 1-carbon metabolism are associated with several common diseases and developmental anomalies including intestinal cancers, vascular disease, cognitive decline, and neural tube defects. The etiology of folate-associated pathologies involves interactions among multiple genetic risk alleles and environmental factors, although the causal mechanisms that define the role of folate and other B-vitamins in these complex disorders remain to be established. Folate and other B-vitamins fundamentally differ from other nutrients that interact with the genome in determining health and disease outcomes in that their interaction is reciprocal. Common gene variants influence the activity of folate-dependent enzymes and anabolic pathways; folate-mediated 1-carbon metabolism is essential for the high-fidelity synthesis of DNA and activated methyl groups that are required for DNA methylation and regulation of chromatin structure. This review focuses on the regulation of folate-mediated 1-carbon metabolism and its role in maintaining genome integrity and on strategies for establishing the metabolic pathways and mechanisms that underlie folate-associated pathologies.
Collapse
Affiliation(s)
- Patrick J Stover
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
| |
Collapse
|
28
|
Pike ST, Rajendra R, Artzt K, Appling DR. Mitochondrial C1-tetrahydrofolate synthase (MTHFD1L) supports the flow of mitochondrial one-carbon units into the methyl cycle in embryos. J Biol Chem 2009; 285:4612-20. [PMID: 19948730 DOI: 10.1074/jbc.m109.079855] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mitochondrial folate-dependent one-carbon (1-C) metabolism converts 1-C donors such as serine and glycine to formate, which is exported and incorporated into the cytoplasmic tetrahydrofolate (THF) 1-C pool. Developing embryos depend on this mitochondrial pathway to provide 1-C units for cytoplasmic process such as de novo purine biosynthesis and the methyl cycle. This pathway is composed of sequential methylene-THF dehydrogenase, methenyl-THF cyclohydrolase, and 10-formyl-THF synthetase activities. In embryonic mitochondria, the bifunctional MTHFD2 enzyme catalyzes the dehydrogenase and cyclohydrolase reactions, but the enzyme responsible for the mitochondrial synthetase reaction has not been identified in embryos. A monofunctional 10-formyl-THF synthetase (MTHFD1L gene product) functions in adult mitochondria and is a likely candidate for the embryonic activity. Here we show that the MTHFD1L enzyme is present in mitochondria from normal embryonic tissues and embryonic fibroblast cell lines, and embryonic mitochondria possess the ability to synthesize formate from glycine. The MTHFD1L transcript was detected at all stages of mouse embryogenesis examined. In situ hybridizations showed that MTHFD1L was expressed ubiquitously throughout the embryo but with localized regions of higher expression. The spatial pattern of MTHFD1L expression was virtually indistinguishable from that of MTHFD2 and MTHFD1 (cytoplasmic C(1)-THF synthase) in embryonic day 9.5 mouse embryos, suggesting coordinated regulation. Finally, we show using stable isotope labeling that in an embryonic mouse cell line, greater than 75% of 1-C units entering the cytoplasmic methyl cycle are mitochondrially derived. Thus, a complete pathway of enzymes for supplying 1-C units from the mitochondria to the methyl cycle in embryonic tissues is established.
Collapse
Affiliation(s)
- Schuyler T Pike
- Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712, USA
| | | | | | | |
Collapse
|
29
|
Verginelli F, Bishehsari F, Napolitano F, Mahdavinia M, Cama A, Malekzadeh R, Miele G, Raiconi G, Tagliaferri R, Mariani-Costantini R. Transitions at CpG dinucleotides, geographic clustering of TP53 mutations and food availability patterns in colorectal cancer. PLoS One 2009; 4:e6824. [PMID: 19718455 PMCID: PMC2730577 DOI: 10.1371/journal.pone.0006824] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Accepted: 07/14/2009] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Colorectal cancer is mainly attributed to diet, but the role exerted by foods remains unclear because involved factors are extremely complex. Geography substantially impacts on foods. Correlations between international variation in colorectal cancer-associated mutation patterns and food availabilities could highlight the influence of foods on colorectal mutagenesis. METHODOLOGY To test such hypothesis, we applied techniques based on hierarchical clustering, feature extraction and selection, and statistical pattern recognition to the analysis of 2,572 colorectal cancer-associated TP53 mutations from 12 countries/geographic areas. For food availabilities, we relied on data extracted from the Food Balance Sheets of the Food and Agriculture Organization of the United Nations. Dendrograms for mutation sites, mutation types and food patterns were constructed through Ward's hierarchical clustering algorithm and their stability was assessed evaluating silhouette values. Feature selection used entropy-based measures for similarity between clusterings, combined with principal component analysis by exhaustive and heuristic approaches. CONCLUSION/SIGNIFICANCE Mutations clustered in two major geographic groups, one including only Western countries, the other Asia and parts of Europe. This was determined by variation in the frequency of transitions at CpGs, the most common mutation type. Higher frequencies of transitions at CpGs in the cluster that included only Western countries mainly reflected higher frequencies of mutations at CpG codons 175, 248 and 273, the three major TP53 hotspots. Pearson's correlation scores, computed between the principal components of the datamatrices for mutation types, food availability and mutation sites, demonstrated statistically significant correlations between transitions at CpGs and both mutation sites and availabilities of meat, milk, sweeteners and animal fats, the energy-dense foods at the basis of "Western" diets. This is best explainable by differential exposure to nitrosative DNA damage due to foods that promote metabolic stress and chronic inflammation.
Collapse
Affiliation(s)
- Fabio Verginelli
- Department of Oncology and Neurosciences, “G. d'Annunzio” University, and Center of Excellence on Aging (CeSI), “G. d'Annunzio” University Foundation, Chieti, Italy
| | - Faraz Bishehsari
- Department of Oncology and Neurosciences, “G. d'Annunzio” University, and Center of Excellence on Aging (CeSI), “G. d'Annunzio” University Foundation, Chieti, Italy
- Digestive Disease Research Center (DDRC), Shariati Hospital, University of Tehran, Tehran, Iran
| | - Francesco Napolitano
- Department of Mathematics and Informatics, University of Salerno, Salerno, Italy
| | - Mahboobeh Mahdavinia
- Department of Oncology and Neurosciences, “G. d'Annunzio” University, and Center of Excellence on Aging (CeSI), “G. d'Annunzio” University Foundation, Chieti, Italy
- Digestive Disease Research Center (DDRC), Shariati Hospital, University of Tehran, Tehran, Iran
| | - Alessandro Cama
- Department of Oncology and Neurosciences, “G. d'Annunzio” University, and Center of Excellence on Aging (CeSI), “G. d'Annunzio” University Foundation, Chieti, Italy
| | - Reza Malekzadeh
- Digestive Disease Research Center (DDRC), Shariati Hospital, University of Tehran, Tehran, Iran
| | - Gennaro Miele
- Department of Physical Sciences, University of Naples, Naples, Italy
| | - Giancarlo Raiconi
- Department of Mathematics and Informatics, University of Salerno, Salerno, Italy
| | - Roberto Tagliaferri
- Department of Mathematics and Informatics, University of Salerno, Salerno, Italy
| | - Renato Mariani-Costantini
- Department of Oncology and Neurosciences, “G. d'Annunzio” University, and Center of Excellence on Aging (CeSI), “G. d'Annunzio” University Foundation, Chieti, Italy
| |
Collapse
|
30
|
Kim YI. Role of the MTHFR polymorphisms in cancer risk modification and treatment. Future Oncol 2009; 5:523-42. [PMID: 19450180 DOI: 10.2217/fon.09.26] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The role of folate, a water-soluble B vitamin, and single nucleotide polymorphisms (SNPs) in the folate metabolic pathway in human health and disease has been rapidly expanding. Recently, functionally significant SNPs in 5,10-methylenetetrahydrofolate reductase (MTHFR), a critical enzyme for intracellular folate homeostasis and metabolism, have been identified and characterized. The MTHFR SNPs are ideal candidates for investigating the role of SNPs in cancer risk modification and treatment because of their well-defined and highly relevant biochemical effects on intracellular folate composition and one-carbon transfer reactions. Indeed, a large body of molecular epidemiologic evidence suggests that the MTHFR 677 variant T allele is associated with cancer risk in a site-specific manner. Furthermore, biologically plausible mechanisms based on the functional consequences of changes in intracellular folate cofactors resulting from the MTHFR 677T variant exist to readily explain cancer risk modification associated with this variant. In addition, a growing body of in vitro and clinical evidence suggests that the MTHFR SNPs may be an important pharmacogenetic determinant of response to and toxicity of 5-fluorouracil (5FU) and methotrexate (MTX)-based cancer and anti-inflammatory chemotherapy. Furthermore, studies suggest that MTHFR inhibition may be a potential target for increasing chemosensitvity of cancer cells to 5FU-based chemotherapy. Because the MTHFR SNPs are prevalent and MTX and 5FU are widely used for the treatment of common cancers and inflammatory conditions, the pharmacogenetic role of the MTHFR SNPs has significant clinical implications. MTHFR SNPs may play an important role in providing rational, effective and safe tailored treatment to patients with cancer and inflammatory disorders requiring 5FU and MTX-based therapy. As such, largescale human studies and in vitro mechanistic studies are warranted to clarify the pharmacogenetic role of the MTHFR SNPs.
Collapse
Affiliation(s)
- Young-In Kim
- Department of Medicine, Room 7258, Medical Sciences Building, University of Toronto, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
| |
Collapse
|
31
|
Sohn KJ, Jang H, Campan M, Weisenberger DJ, Dickhout J, Wang YC, Cho RC, Yates Z, Lucock M, Chiang EP, Austin RC, Choi SW, Laird PW, Kim YI. The methylenetetrahydrofolate reductase C677T mutation induces cell-specific changes in genomic DNA methylation and uracil misincorporation: a possible molecular basis for the site-specific cancer risk modification. Int J Cancer 2009; 124:1999-2005. [PMID: 19123462 DOI: 10.1002/ijc.24003] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene is associated with a decreased risk of colon cancer although it may increase the risk of breast cancer. This polymorphism is associated with changes in intracellular folate cofactors, which may affect DNA methylation and synthesis via altered one-carbon transfer reactions. We investigated the effect of this mutation on DNA methylation and uracil misincorporation and its interaction with exogenous folate in further modulating these biomarkers of one-carbon transfer reactions in an in vitro model of the MTHFR 677T mutation in HCT116 colon and MDA-MB-435 breast adenocarcinoma cells. In HCT116 cells, the MTHFR 677T mutation was associated with significantly increased genomic DNA methylation when folate supply was adequate or high; however, in the setting of folate insufficiency, this mutation was associated with significantly decreased genomic DNA methylation. In contrast, in MDA-MB-435 cells, the MTHFR 677T mutation was associated with significantly decreased genomic DNA methylation when folate supply was adequate or high and with no effect when folate supply was low. The MTHFR 677T mutation was associated with a nonsignificant trend toward decreased and increased uracil misincorporation in HCT116 and MDA-MB-435 cells, respectively. Our data demonstrate for the first time a functional consequence of changes in intracellular folate cofactors resulting from the MTHFR 677T mutation in cells derived from the target organs of interest, thus providing a plausible cellular mechanism that may partly explain the site-specific modification of colon and breast cancer risks associated with the MTHFR C677T mutation.
Collapse
Affiliation(s)
- Kyoung-Jin Sohn
- Department of Medicine, University of Toronto, St. Michael's Hospital, Toronto, Ontario, Canada
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Lamers Y, Williamson J, Ralat M, Quinlivan EP, Gilbert LR, Keeling C, Stevens RD, Newgard CB, Ueland PM, Meyer K, Fredriksen A, Stacpoole PW, Gregory JF. Moderate dietary vitamin B-6 restriction raises plasma glycine and cystathionine concentrations while minimally affecting the rates of glycine turnover and glycine cleavage in healthy men and women. J Nutr 2009; 139:452-60. [PMID: 19158217 PMCID: PMC2646220 DOI: 10.3945/jn.108.099184] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Glycine is a precursor of purines, protein, glutathione, and 1-carbon units as 5,10-methylenetetrahydrofolate. Glycine decarboxylation through the glycine cleavage system (GCS) and glycine-serine transformation by serine hydroxymethyltransferase (SHMT) require pyridoxal 5'-phosphate (PLP; active form of vitamin B-6) as a coenzyme. The intake of vitamin B-6 is frequently low in humans. Therefore, we determined the effects of vitamin B-6 restriction on whole-body glycine flux, the rate of glycine decarboxylation, glycine-to-serine conversion, use of glycine carbons in nucleoside synthesis, and other aspects of 1-carbon metabolism. We used a primed, constant infusion of [1,2-(13)C(2)]glycine and [5,5,5-(2)H(3)]leucine to quantify in vivo kinetics in healthy adults (7 males, 6 females; 20-39 y) of normal vitamin B-6 status or marginal vitamin B-6 deficiency. Vitamin B-6 restriction lowered the plasma PLP concentration from 55 +/- 4 nmol/L (mean +/- SEM) to 23 +/- 1 nmol/L (P < 0.0001), which is consistent with marginal deficiency, whereas the plasma glycine concentration increased (P < 0.01). SHMT-mediated conversion of glycine to serine increased from 182 +/- 7 to 205 +/- 9 micromol x kg(-1) x h(-1) (P < 0.05), but serine production using a GCS-derived 1-carbon unit (93 +/- 9 vs. 91 +/- 6 micromol x kg(-1) x h(-1)) and glycine cleavage (163 +/- 11 vs. 151 +/- 8 micromol x kg(-1) x h(-1)) were not changed by vitamin B-6 restriction. The GCS produced 1-carbon units at a rate (approximately 140-170 micromol x kg(-1) x h(-1)) that greatly exceeds the demand for remethylation and transmethylation processes (approximately 4-7 micromol x kg(-1) x h(-1)). We conclude that the in vivo GCS and SHMT reactions are quite resilient to the effects of marginal vitamin B-6 deficiency, presumably through a compensatory effect of increasing substrate concentration.
Collapse
Affiliation(s)
- Yvonne Lamers
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Jerry Williamson
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Maria Ralat
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Eoin P. Quinlivan
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Lesa R. Gilbert
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Christine Keeling
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Robert D. Stevens
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Christopher B. Newgard
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Per M. Ueland
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Klaus Meyer
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Ase Fredriksen
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Peter W. Stacpoole
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| | - Jesse F. Gregory
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, General Clinical Research Center, Division of Endocrinology and Metabolism, Department of Medicine, and Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL 32611; Sarah W. Stedman Nutrition and Metabolism Center, Duke University Medical Center, Durham, NC 27704; and Section for Pharmacology, Institute of Medicine, University of Bergen, and Bevital A/S, Armauer Hansens Hus, 5021 Bergen, Norway
| |
Collapse
|
33
|
Ulrich CM, Neuhouser M, Liu AY, Boynton A, Gregory JF, Shane B, James SJ, Reed MC, Nijhout HF. Mathematical modeling of folate metabolism: predicted effects of genetic polymorphisms on mechanisms and biomarkers relevant to carcinogenesis. Cancer Epidemiol Biomarkers Prev 2008; 17:1822-31. [PMID: 18628437 DOI: 10.1158/1055-9965.epi-07-2937] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Low-folate status and genetic polymorphisms in folate metabolism have been linked to several cancers. Possible biological mechanisms for this association include effects on purine and thymidine synthesis, DNA methylation, or homocysteine concentrations. The influence of genetic variation in folate metabolism on these putative mechanisms or biomarkers of cancer risk has been largely unexplored. We used a mathematical model that simulates folate metabolism biochemistry to predict (a) the effects of polymorphisms with defined effects on enzyme function (MTHFR and TS) and (b) the effects of potential, as-of-yet-unidentified polymorphisms in a comprehensive set of folate-metabolizing enzymes on biomarkers and mechanisms related to cancer risk. The model suggests that there is substantial robustness in the pathway. Our predictions were consistent with measured effects of known polymorphisms in MTHFR and TS on biomarkers. Polymorphisms that alter enzyme function of FTD, FTS, and MTCH are expected to affect purine synthesis, FTS more so under a low-folate status. In addition, MTCH polymorphisms are predicted to influence thymidine synthesis. Polymorphisms in methyltransferases should affect both methylation rates and thymidylate synthesis. Combinations of polymorphisms in MTHFR, TS, and SHMT are expected to affect nucleotide synthesis in a nonlinear fashion. These investigations provide information on effects of genetic polymorphisms on biomarkers, including those that cannot be measured well, and highlight robustness and sensitivity in this complex biological system with regard to genetic variability. Although the proportional changes in biomarkers of risk with individual polymorphisms are frequently small, they may be quite relevant if present over an individual's lifetime.
Collapse
Affiliation(s)
- Cornelia M Ulrich
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
Fortification of food with folic acid to reduce the number of neural tube defects was introduced 10 y ago in North America. Many countries are considering whether to adopt this policy. When fortification is introduced, several hundred thousand people are exposed to an increased intake of folic acid for each neural tube defect pregnancy that is prevented. Are the benefits to the few outweighed by possible harm to some of the many exposed? In animals, a folic acid-rich diet can influence DNA and histone methylation, which leads to phenotypic changes in subsequent generations. In humans, increased folic acid intake leads to elevated blood concentrations of naturally occurring folates and of unmetabolized folic acid. High blood concentrations of folic acid may be related to decreased natural killer cell cytotoxicity, and high folate status may reduce the response to antifolate drugs used against malaria, rheumatoid arthritis, psoriasis, and cancer. In the elderly, a combination of high folate levels and low vitamin B-12 status may be associated with an increased risk of cognitive impairment and anemia and, in pregnant women, with an increased risk of insulin resistance and obesity in their children. Folate has a dual effect on cancer, protecting against cancer initiation but facilitating progression and growth of preneoplastic cells and subclinical cancers, which are common in the population. Thus, a high folic acid intake may be harmful for some people. Nations considering fortification should be cautious and stimulate further research to identify the effects, good and bad, caused by a high intake of folic acid from fortified food or dietary supplements. Only then can authorities develop the right strategies for the population as a whole.
Collapse
Affiliation(s)
- A David Smith
- Oxford Project to Investigate Memory and Ageing, Department of Physiology, Anatomy & Genetics, University of Oxford, Oxford, United Kingdom.
| | | | | |
Collapse
|
35
|
Beaudin AE, Stover PJ. Folate-mediated one-carbon metabolism and neural tube defects: balancing genome synthesis and gene expression. ACTA ACUST UNITED AC 2007; 81:183-203. [PMID: 17963270 DOI: 10.1002/bdrc.20100] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Neural tube defects (NTDs) refer to a cluster of neurodevelopmental conditions associated with failure of neural tube closure during embryonic development. Worldwide prevalence of NTDs ranges from approximately 0.5 to 60 per 10,000 births, with regional and population-specific variation in prevalence. Numerous environmental and genetic influences contribute to NTD etiology; accumulating evidence from population-based studies has demonstrated that folate status is a significant determinant of NTD risk. Folate-mediated one-carbon metabolism (OCM) is essential for de novo nucleotide biosynthesis, methionine biosynthesis, and cellular methylation reactions. Periconceptional maternal supplementation with folic acid can prevent occurrence of NTDs in the general population by up to 70%; currently several countries fortify their food supply with folic acid for the prevention of NTDs. Despite the unambiguous impact of folate status on NTD risk, the mechanism by which folic acid protects against NTDs remains unknown. Identification of the mechanism by which folate status affects neural tube closure will assist in developing more efficacious and better targeted preventative measures. In this review, we summarize current research on the relationship between folate status and NTDs, with an emphasis on linking genetic variation, folate nutriture, and specific metabolic and/or genomic pathways that intersect to determine NTD outcomes.
Collapse
Affiliation(s)
- Anna E Beaudin
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | | |
Collapse
|
36
|
Quinlivan EP, Gregory JF. DNA digestion to deoxyribonucleoside: a simplified one-step procedure. Anal Biochem 2007; 373:383-5. [PMID: 18028864 DOI: 10.1016/j.ab.2007.09.031] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2007] [Revised: 09/07/2007] [Accepted: 09/25/2007] [Indexed: 11/30/2022]
Abstract
We present a simple and inexpensive 'one-step' protocol for the hydrolysis of DNA to deoxyribonucleosides. Unlike the older DNA hydrolysis protocol which is cumbersome and labor intensive, this new protocol is ideal for high-throughput assays and is suitable automation. Using this protocol we were able to hydrolyze several hundred samples within an 8-hour period. The new protocol is fully compatible with LC-MS/MS and gives similar recoveries for all five major deoxyribonucleosides when compared to the older protocol.
Collapse
Affiliation(s)
- Eoin P Quinlivan
- Biomedical Mass Spectrometry Laboratory, General Clinical Research Center, University of Florida, Gainesville, FL 32611, USA.
| | | |
Collapse
|
37
|
Abstract
Currently available evidence from epidemiologic, animal, and intervention studies does not unequivocally support the role of folate, a water-soluble B vitamin and important cofactor in one-carbon transfer, in the development and progression of colorectal cancer (CRC). However, when the portfolio of evidence from these studies is analyzed critically, the overall conclusion supports the inverse association between folate status and CRC risk. It is becoming increasingly evident that folate possesses dual modulatory effects on colorectal carcinogenesis depending on the timing and dose of folate intervention. Folate deficiency has an inhibitory effect whereas folate supplementation has a promoting effect on the progression of established colorectal neoplasms. In contrast, folate deficiency in normal colorectal mucosa appears to predispose it to neoplastic transformation, and modest levels of folic acid supplementation suppress, whereas supraphysiologic supplemental doses enhance, the development of cancer in normal colorectal mucosa. Several potential mechanisms relating to the disruption of one-carbon transfer reactions exist to support the dual modulatory role of folate in colorectal carcinogenesis. Based on the lack of compelling supportive evidence and on the potential tumor-promoting effect, routine folic acid supplementation should not be recommended as a chemopreventive measure against CRC at present.
Collapse
Affiliation(s)
- Young-In Kim
- Department of Medicine and Nutritional Sciences, Medical Sciences Building, University of Toronto, 1 King's College Circle, Toronto, Ontario, Canada.
| |
Collapse
|
38
|
Hustad S, Midttun Ø, Schneede J, Vollset SE, Grotmol T, Ueland PM. The methylenetetrahydrofolate reductase 677C-->T polymorphism as a modulator of a B vitamin network with major effects on homocysteine metabolism. Am J Hum Genet 2007; 80:846-55. [PMID: 17436239 PMCID: PMC1852731 DOI: 10.1086/513520] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2006] [Accepted: 02/01/2007] [Indexed: 12/22/2022] Open
Abstract
Folates are carriers of one-carbon units and are metabolized by 5,10-methylenetetrahydrofolate reductase (MTHFR) and other enzymes that use riboflavin, cobalamin, or vitamin B6 as cofactors. These B vitamins are essential for the remethylation and transsulfuration of homocysteine, which is an important intermediate in one-carbon metabolism. We studied the MTHFR 677C-->T polymorphism and B vitamins as modulators of one-carbon metabolism in 10,601 adults from the Norwegian Colorectal Cancer Prevention (NORCCAP) cohort, using plasma total homocysteine (tHcy) as the main outcome measure. Mean concentrations of plasma tHcy were 10.4 micromol/liter, 10.9 micromol/liter, and 13.3 micromol/liter in subjects with the CC (51%), CT (41%), and TT (8%) genotypes, respectively. The MTHFR 677C-->T polymorphism, folate, riboflavin, cobalamin, and vitamin B6 were independent predictors of tHcy in multivariate models (P<.001), and genotype effects were strongest when B vitamins were low (P<or=.006). Conversely, the MTHFR polymorphism influenced B vitamin effects, which were strongest in the TT group, in which the estimated tHcy difference between subjects with vitamin concentrations in the lowest compared with the highest quartile was 5.4 micromol/liter for folate, 4.1 micromol/liter for riboflavin, 3.2 micromol/liter for cobalamin, and 2.1 micromol/liter for vitamin B6. Furthermore, interactions between B vitamins were observed, and B vitamins were more strongly related to plasma tHcy when concentrations of other B vitamins were low. The study provides comprehensive data on the MTHFR-B vitamin network, which has major effects on the transfer of one-carbon units. Individuals with the TT genotype were particularly sensitive to the status of several B vitamins and might be candidates for personalized nutritional recommendations.
Collapse
Affiliation(s)
- Steinar Hustad
- The Hormone Laboratory, Haukeland University Hospital, Bergen, Norway.
| | | | | | | | | | | |
Collapse
|
39
|
Lim U, Wang SS, Hartge P, Cozen W, Kelemen LE, Chanock S, Davis S, Blair A, Schenk M, Rothman N, Lan Q. Gene-nutrient interactions among determinants of folate and one-carbon metabolism on the risk of non-Hodgkin lymphoma: NCI-SEER case-control study. Blood 2007; 109:3050-9. [PMID: 17119116 PMCID: PMC1852210 DOI: 10.1182/blood-2006-07-034330] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2006] [Accepted: 11/12/2006] [Indexed: 12/22/2022] Open
Abstract
We previously reported a lower risk of non-Hodgkin lymphoma (NHL) associated with high consumption of vitamin B6 and methionine, dietary determinants of one-carbon metabolism. Evidence has linked genetic variants involved in one-carbon metabolism to NHL. We investigated 30 polymorphisms in 18 genes for their main effect on NHL among 1141 incident cases and 949 population-based controls and examined gene-nutrient interactions in a subgroup of 386 cases and 319 controls who provided detailed food-frequency information. Odds ratios (ORs) and 95% confidence intervals (CIs) were adjusted for age, sex, and race. We observed a decreased risk of NHL over-all with BHMTEx8+453A>T and increased risk with CBS Ex13+41C>T, FPGS Ex15-263T>C, and SHMT1 Ex12+138C>T and Ex12+236C>T. Furthermore, significant gene-nutrient interactions limited the protective association comparing high versus low vitamin B6 to FPGS Ex15-263T>C CC (OR = 0.22; 95% CL = 0.10-0.52), MTHFS IVS2-1411T>G TT/TG (OR = 0.54; 95% CI = 0.36-0.81), and MTR Ex26-20A>G AA (OR = 0.55; 95% CI = 0.35-0.86) genotypes, and the protective association of methionine to FTHFD Ex10-40G>TGG (OR = 0.63; 95% CI = 0.44-0.91), MTHFR Ex8-62A>C CC (OR = 0.13; 95% CI = 0.04-0.39), and MTRR Ex5+136T>CTT (OR = 0.67; 95% CI = 0.47-0.97) genotypes. Warranting replication, our finding of gene-nutrient interactions in one-carbon metabolism supports their etiologic involvement in lymphomagenesis.
Collapse
Affiliation(s)
- Unhee Lim
- Division of Cancer Epidemiology and Genetics, National Cancer Institute (NCI), National Institutes of Health (NIH), Department of Health and Human Services (DHHS), Rockville, MD 20852, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Chiang EP, Wang YC, Tang FY. Folate restriction and methylenetetrahydrofolate reductase 677T polymorphism decreases adoMet synthesis via folate-dependent remethylation in human-transformed lymphoblasts. Leukemia 2007; 21:651-8. [PMID: 17301815 DOI: 10.1038/sj.leu.2404575] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The homozygous mutation (677TT) in the methylenetetrahydrofolate reductase (MTHFR) gene reduces enzyme activity and alters cellular folate composition. Previous epidemiological studies reported a potential protective effect of MTHFR677C --> T against acute lymphocytic leukemia and malignant lymphoma, but the mechanism remains to be determined. We investigated the biochemical impacts of MTHFR677C --> T on cellular S-adenosyl methionine (adoMet) synthesis, global DNA methylation, and de novo purine synthesis, all of which are potential regulatory pathways involved in tumorigenesis. Metabolic fluxes of homocysteine remethylation and de novo purine synthesis were compared between Epstein-Barr virus-transformed lymphoblasts expressing MTHFR 677C and MTHFR 677T using stable isotopic tracers and GCMS. MTHFR TT genotype significantly reduced folate-dependent remethylation under folate restriction, reflecting limited methylated folates under folate restriction. Data also suggested increased formylated folate pool and increased purine synthesis when folate is adequate. The impacts of MTHFR 677T polymorphism appeared closely related to folate status, and such alterations may modulate metabolic pathways involved in cancer onset/progression. The advantage of de novo purine synthesis found in the MTHFR TT genotype may account for the protective effect of MTHFR in hematological malignancies. These transformed cells are potential models for studying the consequences of human genetic variation and cancer pathogenesis.
Collapse
Affiliation(s)
- E-P Chiang
- Department of Food Science and Biotechnology, National Chung Hsing University, Taichung, Taiwan.
| | | | | |
Collapse
|
41
|
Brockton NT. Localized depletion: the key to colorectal cancer risk mediated by MTHFR genotype and folate? Cancer Causes Control 2007; 17:1005-16. [PMID: 16933051 DOI: 10.1007/s10552-006-0051-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2006] [Accepted: 06/15/2006] [Indexed: 10/24/2022]
Abstract
Dietary folate has been consistently associated with reduced risk of colorectal cancer (CRC). One of the known biochemical roles of folate is donation of methyl moieties. DNA hypomethylation is an early and almost ubiquitous occurrence in tumor tissue. Therefore, it was originally suggested that adequate folate intake contributed to reduced risk of CRC by facilitating methyl-mediated silencing of oncogenes. Methylene tetrahydrofolate reductase (MTHFR) metabolizes 5,10-MTHF (important in DNA synthesis) to 5-MTHF (contributes to downstream methylation reactions by regeneration of methionine from homocysteine). A common polymorphism in the MTHFR gene (C677T) results in a thermolabile phenotype associated with increased homocysteine levels and DNA hypomethylation. Consistent with the folate/methylation hypothesis, it was originally proposed that C677T may increase risk of CRC due to hypomethylation of oncogenes. However, most subsequent studies have reported a reduced risk associated with this polymorphism. This is inconsistent with methylation as the mechanism by which folate and MTHFR genotype mediate CRC risk. The hypothesis presented here proposes that localized folate depletion combined with the effect of the C677T polymorphism on enzyme stability, impacts on the DNA synthesis pathway and accounts for the observed variation in risk associated with genotype and folate status.
Collapse
Affiliation(s)
- N T Brockton
- University of Dundee, Maternal and Child Health Sciences, Ninewells Hospital, Dundee, UK.
| |
Collapse
|
42
|
The MTHFR 677TT genotype and folate intake interact to lower global leukocyte DNA methylation in young Mexican American women. Nutr Res 2007; 27:1365-1317. [PMID: 18167510 DOI: 10.1016/j.nutres.2006.12.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
DNA methylation is an epigenetic feature that is associated with X chromosome inactivation, genomic imprinting, transcriptional silencing of genes and genomic stability. Folate provides a labile source of methyl groups which may be used for cellular methylation reactions including DNA methylation. The methylenetetrahydrofolate reductase (MTHFR) 677C-->T variant is an important determinant of folate nutriture and may influence DNA methylation. This study sought to assess the influence of the MTHFR C677T genotype on global leukocyte DNA methylation in young (18-45y) Mexican American women (n=43; 14 CC, 12 CT and 17 TT). Subjects consumed a folate restricted diet (135 mug DFE/d) for 7 wk followed by folate treatment with 400 or 800 mug DFE/d for 7 wk. Global leukocyte DNA methylation was assessed via the cytosine extension assay at week 0, week 7 (after folate restriction) and week 14 (after folate treatment). No main effects of MTHFR C677T genotype or folate intake were detected at any time point during the study. However, at the end of folate treatment (wk 14), DNA methylation was lower (P<0.05) in women with the MTHFR 677TT genotype relative to the CT or CC genotype. Because it is unlikely that folate treatment would result in methyl group loss, we suggest that there was a delay in DNA methylation response to folate intake. Overall, these data suggest that the MTHFR 677TT genotype and folate interact to lower global leukocyte DNA methylation patterns in young Mexican American women.
Collapse
|
43
|
Reed MC, Nijhout HF, Neuhouser ML, Gregory JF, Shane B, James SJ, Boynton A, Ulrich CM. A mathematical model gives insights into nutritional and genetic aspects of folate-mediated one-carbon metabolism. J Nutr 2006; 136:2653-61. [PMID: 16988141 DOI: 10.1093/jn/136.10.2653] [Citation(s) in RCA: 121] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Impaired folate-mediated 1-carbon metabolism has been linked to multiple disease outcomes. A better understanding of the nutritional and genetic influences on this complex biochemical pathway is needed to comprehend their impact on human health. To this end, we created a mathematical model of folate-mediated 1-carbon metabolism. The model uses published data on folate enzyme kinetics and regulatory mechanisms to simulate the impact of genetic and nutritional variation on critical aspects of the pathway. We found that the model predictions match experimental data, while providing novel insights into pathway kinetics. Our primary observations were as follows: 1) the inverse association between folate and homocysteine is strongest at very low folate concentrations, but there is no association at high folate concentrations; 2) the DNA methylation reaction rate is relatively insensitive to changes in folate pool size; and 3) as folate concentrations become very high, enzyme velocities decrease. With regard to polymorphisms in 5,10-methylenetetrahydrofolate reductase (MTHFR), the modeling predicts that decrease MTHFR activity reduces concentrations of S-adenosylmethionine and 5-methyltetrahydrofolate, as well as DNA methylation, while modestly increasing S-adenosylhomocysteine and homocysteine concentrations and thymidine or purine synthesis. Decreased folate together with a simulated vitamin B-12 deficiency results in decreases in DNA methylation and purine and thymidine synthesis. Decreased MTHFR activity superimposed on the B-12 deficiency appears to reverse the declines in purine and thymidine synthesis. These mathematical simulations of folate-mediated 1-carbon metabolism provide a cost-efficient approach to in silico experimentation that can complement and help guide laboratory studies.
Collapse
Affiliation(s)
- Michael C Reed
- Department of Mathematics, Duke University, Durham, NC 27708, USA
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Robien K, Boynton A, Ulrich CM. Pharmacogenetics of folate-related drug targets in cancer treatment. Pharmacogenomics 2006; 6:673-89. [PMID: 16207145 DOI: 10.2217/14622416.6.7.673] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Folate metabolism is the target of two major drug groups: folate antagonists (for example, methotrexate) and thymidylate synthase inhibitors (for example, 5-fluorouracil). These agents are used in the treatment of cancer, as well as for other conditions, such as rheumatoid arthritis. High-dose cancer treatment protocols can induce a state of acute folate depletion which may lead to significant treatment-related toxicity. Polymorphisms in folate-metabolizing enzymes may modify the therapeutic effectiveness and toxicity of these drugs. This review briefly summarizes the drugs targeting the folate pathway and describes common polymorphisms in folate-metabolizing enzymes and transport proteins. Pharmacogenetic studies investigating folate-related drug targets in the treatment of colorectal cancers and hematologic malignancies will subsequently be discussed. Findings to date illustrate a potential for targeting therapy based on patients' genotypes, in order to improve outcomes and reduce toxicity. However, larger, well-designed studies are needed to confirm these early findings.
Collapse
Affiliation(s)
- Kim Robien
- Fred Hutchinson Cancer Research Center, Cancer Prevention Program, 1100 Fairview Ave N, M4-B402, Seattle, WA 98109 1024, USA
| | | | | |
Collapse
|
45
|
Stover PJ, Garza C. Nutrition and developmental biology--implications for public health. Nutr Rev 2006; 64:S60-71; discussion S72-91. [PMID: 16770956 DOI: 10.1111/j.1753-4887.2006.tb00248.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Recent advances in understanding genome-nutrient and nutrient-network interactions, and the modifying effects of genetic variation on their function, have strengthened interests in acute and long-lasting diet/ nutrition influences on health. Relationships between early and mid-gestational and perinatal conditions (including those related to maternal nutrition) and outcomes, and later-onset chronic diseases have received particular attention. Controlled animal experiments support views that responses with long-lasting effects to nutritional milieus are enabled by epigenetic and other metabolic adjustments during critical windows. Thus, underlying mechanisms are beginning to be understood. For example, chromatin remodeling during development can alter gene expression levels, fix or determine future set points critical to intra- and inter-organ communication networks, alter morphogenesis, initiate remodeling events, etc., all with lifelong consequences. These also may affect DNA mutation rates and thereby influence adult cancer and other risks. There is increasing evidence that nutrient-based strategies will be of value to the prevention or delay of onset of chronic diseases and that these strategies may require initiation during embryonic or fetal stages of development to achieve maximal benefit.
Collapse
Affiliation(s)
- Patrick J Stover
- Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853, USA.
| | | |
Collapse
|
46
|
Murphy N, Diviney M, Szer J, Bardy P, Grigg A, Hoyt R, King B, Macgregor L, Holdsworth R, McCluskey J, Tait BD. Donor methylenetetrahydrofolate reductase genotype is associated with graft-versus-host disease in hematopoietic stem cell transplant patients treated with methotrexate. Bone Marrow Transplant 2006; 37:773-9. [PMID: 16518429 DOI: 10.1038/sj.bmt.1705319] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Methotrexate (MTX), used as a graft-versus-host disease (GvHD) prophylactic agent in hematopoietic stem cell transplantation (HSCT), exerts its effect via folate cycle inhibition. A critical enzyme involved in folate metabolism is 5,10-methylenetetrahydrofolate reductase (MTHFR). We examined the association of a single nucleotide polymorphism (SNP) at position 677 in the MTHFR gene on GvHD outcomes in allogeneic HSCT patients administered MTX. MTHFR genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) on 193 HSCT patients and donors. A total of 140 patients were transplanted with an HLA-matched related donor and 53 with an unrelated donor. GvHD outcomes were compared between genotypes by univariate and multivariate analysis. The combined donor 677CT and TT genotypes were associated with a decreased incidence of GvHD (acute and chronic combined) in HSCT recipients with an HLA-matched related donor (75% at 1 year in the CT and TT group compared with 91% in the wild type CC group, P=0.01), increased time to onset of first GvHD (P=0.001) and time to first GvHD treated with systemic therapy (P=0.022). Unrelated donor MTHFR genotype was not associated with outcome parameters and no associations of recipient genotype in either related or unrelated donor cohorts were observed.
Collapse
Affiliation(s)
- N Murphy
- Victorian Transplantation and Immunogenetics Service, Australian Red Cross Blood Service, Melbourne, Australia
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Abstract
Genetic variation is known to affect food tolerances among human subpopulations and may also influence dietary requirements, giving rise to the new field of nutritional genomics and raising the possibility of individualizing nutritional intake for optimal health and disease prevention on the basis of an individual's genome. However, because gene-diet interactions are complex and poorly understood, the use of genomic knowledge to adjust population-based dietary recommendations is not without risk. Whereas current recommendations target most of the population to prevent nutritional deficiencies, inclusion of genomic criteria may indicate subpopulations that may incur differential benefit or risk from generalized recommendations and fortification policies. Current efforts to identify gene alleles that affect nutrient utilization have been enhanced by the identification of genetic variations that have expanded as a consequence of selection under extreme conditions. Identification of genetic variation that arose as a consequence of diet as a selective pressure helps to identify gene alleles that affect nutrient utilization. Understanding the molecular mechanisms underlying gene-nutrient interactions and their modification by genetic variation is expected to result in dietary recommendations and nutritional interventions that optimize individual health.
Collapse
Affiliation(s)
- Patrick J Stover
- Division of Nutritional Sciences, Cornell University, Ithaca NY 14853, USA.
| |
Collapse
|
48
|
Ulrich CM, Curtin K, Potter JD, Bigler J, Caan B, Slattery ML. Polymorphisms in the reduced folate carrier, thymidylate synthase, or methionine synthase and risk of colon cancer. Cancer Epidemiol Biomarkers Prev 2006; 14:2509-16. [PMID: 16284371 DOI: 10.1158/1055-9965.epi-05-0261] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Folate metabolism supports the synthesis of nucleotides as well as the transfer of methyl groups. Polymorphisms in folate-metabolizing enzymes have been shown to affect risk of colorectal neoplasia and other malignancies. Using data from a population-based incident case-control study (1,600 cases and 1,962 controls), we investigated associations between genetic variants in the reduced folate carrier (RFC), thymidylate synthase (TS), methionine synthase (MTR), and 5,10-methylenetetrahydrofolate reductase (MTHFR) and colon cancer risk. The TS enhancer region (TSER) variant was associated with a reduced risk among men [2rpt/2rpt versus 3rpt/3rpt wild-type; odds ratio (OR), 0.7; 95% confidence interval, 0.6-0.98] but not women. When combined genotypes for both TS polymorphisms (TSER and 3'-untranslated region 1494delTTAAAG) were evaluated, ORs for variant genotypes were generally below 1.0, with statistically significantly reduced risks among women. Neither MTR D919G nor RFC 80G>A polymorphisms were associated with altered colon cancer risk. Because folate metabolism is characterized by interrelated reactions, we evaluated gene-gene interactions. Genotypes resulting in reduced MTHFR activity in conjunction with low TS expression were associated with a reduced risk of colon cancer. When dietary intakes were taken into account, individuals with at least one variant TSER allele (3rpt/2rpt or 2rpt/2rpt) were at reduced risk in the presence of a low folate intake. This study supports findings from adenoma studies indicating that purine synthesis may be a relevant biological mechanism linking folate metabolism to colon cancer risk. A pathway-based approach to data analysis is needed to help discern the independent and combined effects of dietary intakes and genetic variability in folate metabolism.
Collapse
Affiliation(s)
- Cornelia M Ulrich
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, M4-B402 Seattle, WA 98109-1024, USA.
| | | | | | | | | | | |
Collapse
|
49
|
Abstract
The B vitamin folate is essential for one-carbon transfer reactions, including those related to the methylation of DNA or other substrates and nucleotide synthesis. Epidemiologic and experimental studies implicate low-folate intakes in elevated risk of colorectal neoplasia and suggest that biologic mechanisms underlying this relation include disturbances in DNA methylation patterns or adverse effects on DNA synthesis and repair. With the completion of the Human Genome Project, a vast amount of data on inherited genetic variability has become available. This genetic information can be used in studies of molecular epidemiology to provide information on multiple aspects of folate metabolism. First, studies linking polymorphisms in folate metabolism to an altered risk of cancer provide evidence for a causal link between this pathway and colorectal carcinogenesis. Second, studies on genetic characteristics can help clarify whether certain individuals may benefit from higher or lower intakes of folate or nutrients relevant to folate metabolism. Third, studies on genetic polymorphisms can generate hypotheses regarding possible biologic mechanisms that connect this pathway to carcinogenesis. Last, genetic variability in folate metabolism may predict survival after a cancer diagnosis, possibly via pharmacogenetic effects. To solve the puzzle of the folate-cancer relation, a transdisciplinary approach is needed that integrates knowledge from epidemiology, clinical studies, experimental nutrition, and mathematical modeling. This review illustrates knowledge that can be gained from molecular epidemiology in the context of nutrigenetics, and the questions that this approach can answer or raise.
Collapse
Affiliation(s)
- Cornelia M Ulrich
- Cancer Prevention Program, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
| |
Collapse
|
50
|
Ulrich CM, Curtin K, Samowitz W, Bigler J, Potter JD, Caan B, Slattery ML. MTHFR variants reduce the risk of G:C->A:T transition mutations within the p53 tumor suppressor gene in colon tumors. J Nutr 2005; 135:2462-7. [PMID: 16177213 DOI: 10.1093/jn/135.10.2462] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
5,10-Methylene-tetrahydrofolate reductase (MTHFR) is a key enzyme in folate-mediated 1-carbon metabolism. Reduced MTHFR activity has been associated with genomic DNA hypomethylation. Methylated cytosines at CpG sites are easily mutated and have been implicated in G:C-->A:T transitions in the p53 tumor suppressor gene. We investigated 2 polymorphisms in the MTHFR gene (C677T and A1298C) and their associations with colon tumor characteristics, including acquired mutations in Ki-ras and p53 genes and microsatellite instability (MSI). The study population comprised 1248 colon cancer cases and 1972 controls, who participated in a population-based case-control study and had been analyzed previously for MSI, acquired mutations in Ki-ras, p53, and germline MTHFR polymorphisms. Multivariable-adjusted odds ratios are presented. Overall, MTHFR genotypes were not associated with MSI status or the presence of any p53 or Ki-ras mutation. Individuals with homozygous variant MTHFR genotypes had a significantly reduced risk of G:C-->A:T transition mutations within the p53 gene, yet, as hypothesized, only at CpG-associated sites [677TT vs. 677CC (referent group) OR = 0.4 (95% CI: 0.1-0.8) for CpG-associated sites; OR = 1.5 (0.7-3.6) for non-CpG associated sites]. Genotypes conferring reduced MTHFR activity were associated with a decreased risk of acquired G:C-->A:T mutations within the p53 gene occurring at CpG sites. Consistent with evidence on the phenotypic effect of the MTHFR C677T variant, we hypothesize that this relation may be explained by modestly reduced genomic DNA methylation, resulting in a lower probability of spontaneous deamination of methylated cytosine to thymidine. These results suggest a novel mechanism by which MTHFR polymorphisms can affect the risk of colon cancer.
Collapse
Affiliation(s)
- C M Ulrich
- Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.
| | | | | | | | | | | | | |
Collapse
|