1
|
Benedict B, Kristensen SM, Duxin JP. What are the DNA lesions underlying formaldehyde toxicity? DNA Repair (Amst) 2024; 138:103667. [PMID: 38554505 DOI: 10.1016/j.dnarep.2024.103667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/22/2024] [Accepted: 03/01/2024] [Indexed: 04/01/2024]
Abstract
Formaldehyde is a highly reactive organic compound. Humans can be exposed to exogenous sources of formaldehyde, but formaldehyde is also produced endogenously as a byproduct of cellular metabolism. Because formaldehyde can react with DNA, it is considered a major endogenous source of DNA damage. However, the nature of the lesions underlying formaldehyde toxicity in cells remains vastly unknown. Here, we review the current knowledge of the different types of nucleic acid lesions that are induced by formaldehyde and describe the repair pathways known to counteract formaldehyde toxicity. Taking this knowledge together, we discuss and speculate on the predominant lesions generated by formaldehyde, which underly its natural toxicity.
Collapse
Affiliation(s)
- Bente Benedict
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Stella Munkholm Kristensen
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark
| | - Julien P Duxin
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen DK-2200, Denmark.
| |
Collapse
|
2
|
Abuja PM, Pabst D, Bourgeois B, Loibner M, Ulz C, Kufferath I, Fackelmann U, Stumptner C, Kraemer R, Madl T, Zatloukal K. Residual Humidity in Paraffin-Embedded Tissue Reduces Nucleic Acid Stability. Int J Mol Sci 2023; 24:8010. [PMID: 37175716 PMCID: PMC10178321 DOI: 10.3390/ijms24098010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/11/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023] Open
Abstract
Molecular diagnostics in healthcare relies increasingly on genomic and transcriptomic methodologies and requires appropriate tissue specimens from which nucleic acids (NA) of sufficiently high quality can be obtained. Besides the duration of ischemia and fixation type, NA quality depends on a variety of other pre-analytical parameters, such as storage conditions and duration. It has been discussed that the improper dehydration of tissue during processing influences the quality of NAs and the shelf life of fixed tissue. Here, we report on establishing a method for determining the amount of residual water in fixed, paraffin-embedded tissue (fixed by neutral buffered formalin or a non-crosslinking fixative) and its correlation to the performance of NAs in quantitative real-time polymerase chain reaction (qRT-PCR) analyses. The amount of residual water depended primarily on the fixative type and the dehydration protocol and, to a lesser extent, on storage conditions and time. Moreover, we found that these parameters were associated with the qRT-PCR performance of extracted NAs. Besides the cross-linking of NAs and the modification of nucleobases by formalin, the hydrolysis of NAs by residual water was found to contribute to reduced qRT-PCR performance. The negative effects of residual water on NA stability are not only important for the design and interpretation of research but must also be taken into account in clinical diagnostics where the reanalysis of archived tissue from a primary tumor may be required (e.g., after disease recurrence). We conclude that improving the shelf life of fixed tissue requires meticulous dehydration and dry storage to minimize the degradative influence of residual water on NAs.
Collapse
Affiliation(s)
- Peter M. Abuja
- Diagnostic & Research Centre for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Daniela Pabst
- Diagnostic & Research Centre for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Benjamin Bourgeois
- Gottfried Schatz Research Centre for Cell Signalling, Metabolism and Ageing, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Martina Loibner
- Diagnostic & Research Centre for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Christine Ulz
- Diagnostic & Research Centre for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Iris Kufferath
- Diagnostic & Research Centre for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Ulrike Fackelmann
- Diagnostic & Research Centre for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Cornelia Stumptner
- Diagnostic & Research Centre for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| | - Rainer Kraemer
- Berghof Products & Instruments GmbH, 72800 Eningen, Germany
| | - Tobias Madl
- Gottfried Schatz Research Centre for Cell Signalling, Metabolism and Ageing, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
- BioTechMed-Graz, 8010 Graz, Austria
| | - Kurt Zatloukal
- Diagnostic & Research Centre for Molecular Biomedicine, Institute of Pathology, Medical University of Graz, Neue Stiftingtalstrasse 6, 8010 Graz, Austria
| |
Collapse
|
3
|
Angelov D, Boopathi R, Lone IN, Menoni H, Dimitrov S, Cadet J. Capturing Protein-Nucleic Acid Interactions by High-Intensity Laser-Induced Covalent Crosslinking. Photochem Photobiol 2022; 99:296-312. [PMID: 35997098 DOI: 10.1111/php.13699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/21/2022] [Indexed: 11/30/2022]
Abstract
Interactions of DNA with structural proteins such as histones, regulatory proteins, and enzymes play a crucial role in major cellular processes such as transcription, replication and repair. The in vivo mapping and characterization of the binding sites of the involved biomolecules are of primary importance for a better understanding of genomic deployment that is implicated in tissue and developmental stage-specific gene expression regulation. The most powerful and commonly used approach to date is immunoprecipitation of chemically cross-linked chromatin (XChIP) coupled with sequencing analysis (ChIP-seq). While the resolution and the sensitivity of the high-throughput sequencing techniques have been constantly improved little progress has been achieved in the crosslinking step. Because of its low efficiency the use of the conventional UVC lamps remains very limited while the formaldehyde method was established as the "gold standard" crosslinking agent. Efficient biphotonic crosslinking of directly interacting nucleic acid-protein complexes by a single short UV laser pulse has been introduced as an innovative technique for overcoming limitations of conventionally used chemical and photochemical approaches. In this survey, the main available methods including the laser approach are critically reviewed for their ability to generate DNA-protein crosslinks in vitro model systems and cells.
Collapse
Affiliation(s)
- Dimitar Angelov
- Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Biologie et de Modélisation de la Cellule LBMC, CNRS UMR 5239, 46 Allée d'Italie, 69007, Lyon, France.,Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Balçova, Izmir 35330, Turkey
| | - Ramachandran Boopathi
- Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS, Laboratoire de Biologie et de Modélisation de la Cellule LBMC, CNRS UMR 5239, 46 Allée d'Italie, 69007, Lyon, France.,Université Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), 38000, Grenoble, France
| | - Imtiaz Nisar Lone
- Izmir Biomedicine and Genome Center, Dokuz Eylul University Health Campus, Balçova, Izmir 35330, Turkey
| | - Hervé Menoni
- Université Grenoble Alpes, CNRS UMR 5309, INSERM U1209, Institute for Advanced Biosciences (IAB), Site Santé - Allée des Alpes, 38700, La Tronche, France
| | - Stefan Dimitrov
- Université Grenoble Alpes, CNRS UMR 5309, INSERM U1209, Institute for Advanced Biosciences (IAB), Site Santé - Allée des Alpes, 38700, La Tronche, France
| | - Jean Cadet
- Département de Médecine nucléaire et Radiobiologie, Faculté de Médecine, Université de Sherbrooke, Sherbrooke, J1H 5N4, Québec, Canada
| |
Collapse
|
4
|
FANCD2 maintains replication fork stability during misincorporation of the DNA demethylation products 5-hydroxymethyl-2'-deoxycytidine and 5-hydroxymethyl-2'-deoxyuridine. Cell Death Dis 2022; 13:503. [PMID: 35624090 PMCID: PMC9142498 DOI: 10.1038/s41419-022-04952-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 05/12/2022] [Accepted: 05/13/2022] [Indexed: 12/14/2022]
Abstract
Fanconi anemia (FA) is a rare hereditary disorder caused by mutations in any one of the FANC genes. FA cells are mainly characterized by extreme hypersensitivity to interstrand crosslink (ICL) agents. Additionally, the FA proteins play a crucial role in concert with homologous recombination (HR) factors to protect stalled replication forks. Here, we report that the 5-methyl-2'-deoxycytidine (5mdC) demethylation (pathway) intermediate 5-hydroxymethyl-2'-deoxycytidine (5hmdC) and its deamination product 5-hydroxymethyl-2'-deoxyuridine (5hmdU) elicit a DNA damage response, chromosome aberrations, replication fork impairment and cell viability loss in the absence of FANCD2. Interestingly, replication fork instability by 5hmdC or 5hmdU was associated to the presence of Poly(ADP-ribose) polymerase 1 (PARP1) on chromatin, being both phenotypes exacerbated by olaparib treatment. Remarkably, Parp1-/- cells did not show any replication fork defects or sensitivity to 5hmdC or 5hmdU, suggesting that retained PARP1 at base excision repair (BER) intermediates accounts for the observed replication fork defects upon 5hmdC or 5hmdU incorporation in the absence of FANCD2. We therefore conclude that 5hmdC is deaminated in vivo to 5hmdU, whose fixation by PARP1 during BER, hinders replication fork progression and contributes to genomic instability in FA cells.
Collapse
|
5
|
Yamada M, Kawamura M, Yamada T. Preparation of bioplastic consisting of salmon milt DNA. Sci Rep 2022; 12:7423. [PMID: 35523933 PMCID: PMC9076882 DOI: 10.1038/s41598-022-11482-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 04/18/2022] [Indexed: 11/09/2022] Open
Abstract
The microplastic that pollutes the ocean is a serious problem around the world. The bioplastic consisting of biopolymers which is degraded in nature, is one of the strategies to solve this problem. Although the bioplastics consisting of protein, polysaccharide, polylactic acid, etc., have been reported, which consist of DNA, one of the most important materials in the genetic process, have not been reported to the best of our knowledge. In addition, a large amount of DNA-containing materials, such as salmon milts, is discarded as industrial waste around the world. Therefore, we demonstrated the preparation of a bioplastic consisting of salmon milt DNA. The DNA plastic was prepared by the immersion of a DNA pellet in a formaldehyde (HCHO) solution and heating. As a result, the water-stable DNA plastics were obtained at the HCHO concentration of 20% or more. Particularly, the DNA plastic with a 25% HCHO treatment showed water-insoluble, thermally stable, and highly mechanical properties. These are due to the formation of a three-dimensional network via the crosslinking reaction between the DNA chains. In addition, since DNA in plastic possesses the double-stranded structure, these plastics effectively accumulated the DNA intercalator, such as ethidium bromide. Furthermore, the DNA plastics indicated a biodegradable property in a nuclease-containing aqueous solution and the biodegradable stability was able to be controlled by the HCHO concentration. Therefore, salmon milt DNA has shown the potential to be a biodegradable plastic.
Collapse
Affiliation(s)
- Masanori Yamada
- Department of Chemistry, Faculty of Science, Okayama University of Science, Ridaicho, Kita-ku, Okayama, 700-0005, Japan.
| | - Midori Kawamura
- Department of Chemistry, Faculty of Science, Okayama University of Science, Ridaicho, Kita-ku, Okayama, 700-0005, Japan
| | - Tetsuya Yamada
- Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| |
Collapse
|
6
|
Alternative tissue fixation for combined histopathological and molecular analysis in a clinically representative setting. Histochem Cell Biol 2021; 156:595-607. [PMID: 34905068 PMCID: PMC8695534 DOI: 10.1007/s00418-021-02029-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2021] [Indexed: 11/26/2022]
Abstract
Formalin is the principal tissue fixative used worldwide for clinical and research purposes. Despite optimal preservation of morphology, its preservation of DNA and RNA is poor. As clinical diagnostics increasingly incorporates molecular-based analysis, the requirement for maintaining nucleic acid quality is of increasing importance. Here we assess an alternative non-formalin-based tissue fixation method, PAXgene Tissue system, with the aim of better preserving nucleic acids, while maintaining the quality of the tissue to be used for vital existing diagnostic techniques. In this study, these criteria are assessed in a clinically representative setting. In total, 203 paired PAXgene Tissue and formalin-fixed samples were obtained. Blind-scored haematoxylin and eosin (H&E) sections showed comparable and acceptable staining. Immunohistochemistry (IHC) staining was suboptimal using existing protocols but improved with minor method adjustment and optimisation. Quality of DNA and RNA was significantly improved by PAXgene tissue fixation [RIN 2.8 versus 3.8 (p < 0.01), DIN 5.68 versus 6.77 (p < 0.001)], which translated into improved performance on qPCR assay. These results demonstrate the potential of PAXgene Tissue to be used routinely in place of formalin, maintaining adequate histological staining and significantly improving the preservation of biological molecules in the genomic era.
Collapse
|
7
|
Vishnu US, Estève PO, Chin HG, Pradhan S. One-pot universal NicE-seq: all enzymatic downstream processing of 4% formaldehyde crosslinked cells for chromatin accessibility genomics. Epigenetics Chromatin 2021; 14:53. [PMID: 34895293 PMCID: PMC8665596 DOI: 10.1186/s13072-021-00427-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/16/2021] [Indexed: 11/20/2022] Open
Abstract
Background Accessible chromatin landscape allows binding of transcription factors, and remodeling of promoter and enhancer elements during development. Chromatin accessibility along with integrated multiomics approaches have been used for determining molecular subtypes of cancer in patient samples. Results One-pot Universal NicE-seq (One-pot UniNicE-seq) is an improved accessible chromatin profiling method that negate DNA purification and incorporate sonication free enzymatic fragmentation before library preparation and is suited to a variety of mammalian cells. One-pot UniNicE-seq is versatile, capable of profiling 4% formaldehyde fixed chromatin in as low as 25 fixed cells. Accessible chromatin profile is more efficient on formaldehyde-fixed cells using one-pot UniNicE-seq compared to Tn5 transposon mediated methods, demonstrating its versatility. Conclusion One-pot UniNicE-seq allows the entire process of accessible chromatin labeling and enrichment in one pot at 4% formaldehyde cross-linking conditions. It doesn’t require enzyme titration, compared to other technologies, since accessible chromatin is labelled with 5mC incorporation and deter degradation by nicking enzyme, thus opening the possibility for automation. Supplementary Information The online version contains supplementary material available at 10.1186/s13072-021-00427-2.
Collapse
Affiliation(s)
| | | | - Hang Gyeong Chin
- Genome Biology Division, New England Biolabs, Inc., Ipswich, MA, 01983, USA
| | - Sriharsa Pradhan
- Genome Biology Division, New England Biolabs, Inc., Ipswich, MA, 01983, USA.
| |
Collapse
|
8
|
Varela JG, Pierce LE, Guo X, Price NE, Johnson KM, Yang Z, Wang Y, Gates KS. Interstrand Cross-Link Formation Involving Reaction of a Mispaired Cytosine Residue with an Abasic Site in Duplex DNA. Chem Res Toxicol 2021; 34:1124-1132. [PMID: 33784065 PMCID: PMC8650171 DOI: 10.1021/acs.chemrestox.1c00004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The formation of interstrand cross-links in duplex DNA is important in biology, medicine, and biotechnology. Interstrand cross-links arising from the reaction of the aldehyde residue of an abasic (apurinic or AP) site with the exocyclic amino groups of guanine or adenine residues on the opposing strand of duplex DNA have previously been characterized. The canonical nucleobase cytosine has an exocyclic amino group but its ability to form interstrand cross-links by reaction with an AP site has not been characterized before now. Here it is shown that substantial yields of interstrand cross-links are generated in sequences having a mispaired cytosine residue located one nucleotide to the 3'-side of the AP site on the opposing strand (e.g., 5'XA/5'CA, where X = AP). Formation of the dC-AP cross-link is pH-dependent, with significantly higher yields at pH 5 than pH 7. Once formed, the dC-AP cross-link is quite stable, showing less than 5% dissociation over the course of 96 h at pH 7 and 37 °C. No significant yields of cross-link are observed when the cytosine residue is paired with its Watson-Crick partner guanine. It was also shown that a single AP site can engage with multiple nucleobase cross-linking partners in some sequences. Specifically, the dG-AP and dC-AP cross-links coexist in dynamic equilibrium in the sequence 5'CXA/5'CAG (X = AP). In this sequence, the dC-AP cross-link dominates. However, in the presence of NaBH3CN, irreversible reduction of small amounts of the dG-AP cross-link present in the mixture shifts the equilibria away from the dC-AP cross-link toward good yields of the dG-APred cross-link.
Collapse
Affiliation(s)
- Jacqueline Gamboa Varela
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Luke E. Pierce
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Xu Guo
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Nathan E. Price
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
- Department of Chemistry, University of California-Riverside, Riverside, California 92521-0403, United States
| | - Kevin M. Johnson
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Zhiyu Yang
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Yinsheng Wang
- Department of Chemistry, University of California-Riverside, Riverside, California 92521-0403, United States
| | - Kent S. Gates
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
- University of Missouri, Department of Biochemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| |
Collapse
|
9
|
Majikes JM, Patrone PN, Kearsley AJ, Zwolak M, Liddle JA. Failure Mechanisms in DNA Self-Assembly: Barriers to Single-Fold Yield. ACS NANO 2021; 15:3284-3294. [PMID: 33565312 PMCID: PMC11005093 DOI: 10.1021/acsnano.0c10114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Understanding the folding process of DNA origami is a critical stepping stone to the broader implementation of nucleic acid nanofabrication technology but is notably nontrivial. Origami are formed by several hundred cooperative hybridization events-folds-between spatially separate domains of a scaffold, derived from a viral genome, and oligomeric staples. Individual events are difficult to detect. Here, we present a real-time probe of the unit operation of origami assembly, a single fold, across the scaffold as a function of hybridization domain separation-fold distance-and staple/scaffold ratio. This approach to the folding problem elucidates a predicted but previously unobserved blocked state that acts as a limit on yield for single folds, which may manifest as a barrier in whole origami assembly.
Collapse
Affiliation(s)
- Jacob M. Majikes
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6203, United States
| | - Paul N. Patrone
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6203, United States
| | - Anthony J. Kearsley
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6203, United States
| | - Michael Zwolak
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6203, United States
| | - J. Alexander Liddle
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6203, United States
| |
Collapse
|
10
|
Housh K, Jha JS, Haldar T, Amin SBM, Islam T, Wallace A, Gomina A, Guo X, Nel C, Wyatt JW, Gates KS. Formation and repair of unavoidable, endogenous interstrand cross-links in cellular DNA. DNA Repair (Amst) 2020; 98:103029. [PMID: 33385969 DOI: 10.1016/j.dnarep.2020.103029] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 11/24/2020] [Indexed: 02/08/2023]
Abstract
Genome integrity is essential for life and, as a result, DNA repair systems evolved to remove unavoidable DNA lesions from cellular DNA. Many forms of life possess the capacity to remove interstrand DNA cross-links (ICLs) from their genome but the identity of the naturally-occurring, endogenous substrates that drove the evolution and retention of these DNA repair systems across a wide range of life forms remains uncertain. In this review, we describe more than a dozen chemical processes by which endogenous ICLs plausibly can be introduced into cellular DNA. The majority involve DNA degradation processes that introduce aldehyde residues into the double helix or reactions of DNA with endogenous low molecular weight aldehyde metabolites. A smaller number of the cross-linking processes involve reactions of DNA radicals generated by oxidation.
Collapse
Affiliation(s)
- Kurt Housh
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Jay S Jha
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Tuhin Haldar
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Saosan Binth Md Amin
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Tanhaul Islam
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Amanda Wallace
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Anuoluwapo Gomina
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Xu Guo
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Christopher Nel
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Jesse W Wyatt
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States
| | - Kent S Gates
- University of Missouri, Department of Chemistry, 125 Chemistry Building, Columbia, MO 65211, United States; University of Missouri, Department of Biochemistry, Columbia, MO 65211, United States.
| |
Collapse
|
11
|
Reversal of nucleobase methylation by dioxygenases. Nat Chem Biol 2020; 16:1160-1169. [DOI: 10.1038/s41589-020-00675-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 09/11/2020] [Indexed: 12/12/2022]
|
12
|
Fattorini P, Forzato C, Tierno D, De Martino E, Azzalini E, Canzonieri V, Stanta G, Bonin S. A Novel HPLC-Based Method to Investigate on RNA after Fixation. Int J Mol Sci 2020; 21:ijms21207540. [PMID: 33066070 PMCID: PMC7588918 DOI: 10.3390/ijms21207540] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/24/2020] [Accepted: 10/09/2020] [Indexed: 12/13/2022] Open
Abstract
RNA isolated from fixed and paraffin-embedded tissues is widely used in biomedical research and molecular pathology for diagnosis. In the present study, we have set-up a method based on high performance liquid chromatography (HPLC) to investigate the effects of different fixatives on RNA. By the application of the presented method, which is based on the Nuclease S1 enzymatic digestion of RNA extracts followed by a HPLC analysis, it is possible to quantify the unmodified nucleotide monophosphates (NMPs) in the mixture and recognize their hydroxymethyl derivatives as well as other un-canonical RNA moieties. The results obtained from a set of mouse livers fixed/embedded with different protocols as well from a set of clinical samples aged 0 to 30 years-old show that alcohol-based fixatives do not induce chemical modification of the nucleic acid under ISO standard recommendations and confirm that pre-analytical conditions play a major role in RNA preservation.
Collapse
Affiliation(s)
- Paolo Fattorini
- DSM-Department of Medical Sciences, University of Trieste, 34149 Trieste, Italy; (P.F.); (D.T.); (E.D.M.); (E.A.); (V.C.); (G.S.)
| | - Cristina Forzato
- Department of Chemical and Pharmaceutical Sciences, University of Trieste, 34127 Trieste, Italy;
| | - Domenico Tierno
- DSM-Department of Medical Sciences, University of Trieste, 34149 Trieste, Italy; (P.F.); (D.T.); (E.D.M.); (E.A.); (V.C.); (G.S.)
- Doctorate of Nanotechnology, University of Trieste, 34100 Trieste, Italy
| | - Eleonora De Martino
- DSM-Department of Medical Sciences, University of Trieste, 34149 Trieste, Italy; (P.F.); (D.T.); (E.D.M.); (E.A.); (V.C.); (G.S.)
| | - Eros Azzalini
- DSM-Department of Medical Sciences, University of Trieste, 34149 Trieste, Italy; (P.F.); (D.T.); (E.D.M.); (E.A.); (V.C.); (G.S.)
| | - Vincenzo Canzonieri
- DSM-Department of Medical Sciences, University of Trieste, 34149 Trieste, Italy; (P.F.); (D.T.); (E.D.M.); (E.A.); (V.C.); (G.S.)
- Pathology Unit, IRCCS CRO Aviano-National Cancer Institute, 33081 Aviano, Italy
| | - Giorgio Stanta
- DSM-Department of Medical Sciences, University of Trieste, 34149 Trieste, Italy; (P.F.); (D.T.); (E.D.M.); (E.A.); (V.C.); (G.S.)
| | - Serena Bonin
- DSM-Department of Medical Sciences, University of Trieste, 34149 Trieste, Italy; (P.F.); (D.T.); (E.D.M.); (E.A.); (V.C.); (G.S.)
- Correspondence: ; Tel.: +39-040-399-3266
| |
Collapse
|
13
|
Drew SC. Aldehyde Production as a Calibrant of Ultrasonic Power Delivery During Protein Misfolding Cyclic Amplification. Protein J 2020; 39:501-508. [PMID: 33011953 DOI: 10.1007/s10930-020-09920-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2020] [Indexed: 11/30/2022]
Abstract
The protein misfolding cyclic amplification (PMCA) technique employs repeated cycles of incubation and sonication to amplify minute amounts of misfolded protein conformers. Spontaneous (de novo) prion formation and ultrasonic power level represent two potentially interrelated sources of variation that frustrate attempts to replicate results from different laboratories. We previously established that water splitting during PMCA provides a radical-rich environment leading to oxidative damage to substrate molecules as well as the polypropylene PCR tubes used for sample containment. Here it is shown that the cross-linking agent formaldehyde is generated from buffer ions that are attacked by hydroxyl radicals. In addition, free radical damage to protein, nucleic acid, lipid, and detergent molecules produces a substantial concentration of aldehydes (hundreds of micromolar). The measurement of aldehydes using the Hantzsch reaction provides a reliable and inexpensive method for measuring the power delivered to individual PMCA samples, and for calibrating the power output characteristics of an individual sonicator. The proposed method may also be used to better account for inter-assay and inter-laboratory variation in prion replication and de novo prion generation, the latter of which may correlate with aldehyde-induced cross-linking of substrate molecules.
Collapse
Affiliation(s)
- Simon C Drew
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Victoria, 3010, Australia. .,Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, 02-106, Poland.
| |
Collapse
|
14
|
Yamada M, Morimitsu S, Hosono E, Yamada T. Preparation of bioplastic using soy protein. Int J Biol Macromol 2020; 149:1077-1083. [DOI: 10.1016/j.ijbiomac.2020.02.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/26/2020] [Accepted: 02/04/2020] [Indexed: 12/11/2022]
|
15
|
Hernandez-Castillo C, Termini J, Shuck S. DNA Adducts as Biomarkers To Predict, Prevent, and Diagnose Disease-Application of Analytical Chemistry to Clinical Investigations. Chem Res Toxicol 2020; 33:286-307. [PMID: 31638384 DOI: 10.1021/acs.chemrestox.9b00295] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Characterization of the chemistry, structure, formation, and metabolism of DNA adducts has been one of the most significant contributions to the field of chemical toxicology. This work provides the foundation to develop analytical methods to measure DNA adducts, define their relationship to disease, and establish clinical tests. Monitoring exposure to environmental and endogenous toxicants can predict, diagnose, and track disease as well as guide therapeutic treatment. DNA adducts are one of the most promising biomarkers of toxicant exposure owing to their stability, appearance in numerous biological matrices, and characteristic analytical properties. In addition, DNA adducts can induce mutations to drive disease onset and progression and can serve as surrogate markers of chemical exposure. In this perspective, we highlight significant advances made within the past decade regarding DNA adduct quantitation using mass spectrometry. We hope to expose a broader audience to this field and encourage analytical chemistry laboratories to explore how specific adducts may be related to various pathologies. One of the limiting factors in developing clinical tests to measure DNA adducts is cohort size; ideally, the cohort would allow for model development and then testing of the model to the remaining cohort. The goals of this perspective article are to (1) provide a summary of analyte levels measured using state-of-the-art analytical methods, (2) foster collaboration, and (3) highlight areas in need of further investigation.
Collapse
Affiliation(s)
- Carlos Hernandez-Castillo
- Department of Molecular Medicine , Beckman Research Institute at City of Hope Duarte , California 91010 , United States
| | - John Termini
- Department of Molecular Medicine , Beckman Research Institute at City of Hope Duarte , California 91010 , United States
| | - Sarah Shuck
- Department of Molecular Medicine , Beckman Research Institute at City of Hope Duarte , California 91010 , United States
| |
Collapse
|
16
|
Muhammad II, Kong SL, Akmar Abdullah SN, Munusamy U. RNA-seq and ChIP-seq as Complementary Approaches for Comprehension of Plant Transcriptional Regulatory Mechanism. Int J Mol Sci 2019; 21:E167. [PMID: 31881735 PMCID: PMC6981605 DOI: 10.3390/ijms21010167] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 12/19/2019] [Accepted: 12/23/2019] [Indexed: 02/07/2023] Open
Abstract
The availability of data produced from various sequencing platforms offer the possibility to answer complex questions in plant research. However, drawbacks can arise when there are gaps in the information generated, and complementary platforms are essential to obtain more comprehensive data sets relating to specific biological process, such as responses to environmental perturbations in plant systems. The investigation of transcriptional regulation raises different challenges, particularly in associating differentially expressed transcription factors with their downstream responsive genes. In this paper, we discuss the integration of transcriptional factor studies through RNA sequencing (RNA-seq) and Chromatin Immunoprecipitation sequencing (ChIP-seq). We show how the data from ChIP-seq can strengthen information generated from RNA-seq in elucidating gene regulatory mechanisms. In particular, we discuss how integration of ChIP-seq and RNA-seq data can help to unravel transcriptional regulatory networks. This review discusses recent advances in methods for studying transcriptional regulation using these two methods. It also provides guidelines for making choices in selecting specific protocols in RNA-seq pipelines for genome-wide analysis to achieve more detailed characterization of specific transcription regulatory pathways via ChIP-seq.
Collapse
Affiliation(s)
- Isiaka Ibrahim Muhammad
- Laboratory of Plantation Science and Technology, Institute of Plantation Studies, Universiti Putra Malaysia, Selangor 43400, Malaysia; (I.I.M.); (S.L.K.); (U.M.)
| | - Sze Ling Kong
- Laboratory of Plantation Science and Technology, Institute of Plantation Studies, Universiti Putra Malaysia, Selangor 43400, Malaysia; (I.I.M.); (S.L.K.); (U.M.)
| | - Siti Nor Akmar Abdullah
- Laboratory of Plantation Science and Technology, Institute of Plantation Studies, Universiti Putra Malaysia, Selangor 43400, Malaysia; (I.I.M.); (S.L.K.); (U.M.)
- Department of Agriculture Technology, Faculty of Agriculture, Universiti Putra Malaysia, Selangor 43400, Malaysia
| | - Umaiyal Munusamy
- Laboratory of Plantation Science and Technology, Institute of Plantation Studies, Universiti Putra Malaysia, Selangor 43400, Malaysia; (I.I.M.); (S.L.K.); (U.M.)
| |
Collapse
|
17
|
Reinbold R, John T, Spingardi P, Kawamura A, Thompson AL, Schofield CJ, Hopkinson RJ. Formaldehyde quantification using ampicillin is not selective. Sci Rep 2019; 9:18289. [PMID: 31797955 PMCID: PMC6892939 DOI: 10.1038/s41598-019-54610-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 10/22/2019] [Indexed: 01/07/2023] Open
Abstract
Formaldehyde (HCHO) is a simple and highly reactive human metabolite but its biochemistry is poorly defined. A limiting factor in HCHO research is lack of validated quantification methods for HCHO relevant to biological samples. We describe spectroscopic studies on a reported fluorescence-based HCHO detection method involving its reaction with ampicillin. The results validate the structure and fluorescence properties of the HCHO-ampicillin reaction product. However, the same adduct is observed after reaction of ampicillin with glyoxylate. Related fluorophores were formed with other biologically relevant carbonyl compounds. Overall, our studies suggest the ampicillin method is not reliable for selective detection and quantification of HCHO in biological samples.
Collapse
Affiliation(s)
- Raphael Reinbold
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Tobias John
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | - Paolo Spingardi
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7DQ, United Kingdom
| | - Akane Kawamura
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, Wellcome Trust Centre for Human Genetics, Roosevelt Drive, Oxford, OX3 7BN, United Kingdom
| | - Amber L Thompson
- Chemical Crystallography, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom
| | | | - Richard J Hopkinson
- Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA, United Kingdom.
- Leicester Institute of Structural and Chemical Biology and School of Chemistry, University of Leicester, Henry Wellcome Building, Lancaster Road, Leicester, LE1 7RH, United Kingdom.
| |
Collapse
|
18
|
Abstract
AbstractFormaldehyde is a biological electrophile produced via processes including enzymatic demethylation. Despite its apparent simplicity, the reactions of formaldehyde with even basic biological components are incompletely defined. Here we report NMR-based studies on the reactions of formaldehyde with common proteinogenic and other nucleophilic amino acids. The results reveal formaldehyde reacts at different rates, forming hydroxymethylated, cyclised, cross-linked, or disproportionated products of varying stabilities. Of the tested common amino acids, cysteine reacts most efficiently, forming a stable thiazolidine. The reaction with lysine is less efficient; low levels of an Nε-methylated product are observed, raising the possibility of non-enzymatic lysine methylation by formaldehyde. Reactions with formaldehyde are faster than reactions with other tested biological carbonyl compounds, and the adducts are also more stable. The results reveal reactions of formaldehyde with amino acids, and by extension peptides and proteins, have potential roles in healthy and diseased biology, as well as in evolution.
Collapse
|
19
|
Abstract
Indirect immunofluorescence assay (IFA) has been used for detection of autoantibodies against cellular antigens for more than 50 years. Originally using rodent tissue as substrate, the method was optimized by using the human immortal HEp-2 cell line derived from a larynx epidermal carcinoma. The HEp-2/IFA platform allows for optimal visualization of several cellular domains recognized by autoantibodies in the samples being tested. Serial dilution allows for the estimation of the concentration (titer) of the autoantibodies in the sample. Judicious analysis of the topographic distribution of the immunofluorescence (pattern) provides useful hints on the most plausible autoantigens being recognized, vis-à-vis the cognate autoantibodies. The importance of the HEp-2/IFA pattern has been recently emphasized by the International Consensus on ANA Patterns (ICAP), an initiative that established a comprehensive classification of the most relevant and prevalent HEp-2/IFA patterns (designated anti-cell (AC) patterns) and harmonized its nomenclature. The former designation "antinuclear antibody test" has been progressively replaced by the term "anti-cell antibody test," due to the recognition that the HEp-2/IFA method in fact allows the detection of autoantibodies to several cellular domains, such as the cytoplasm and mitotic apparatus.The performance of the HEp-2/IFA test is strongly influenced by several technical details, including cell culture conditions, cell fixation and permeabilization methods, choice and titration of fluorochrome-conjugated secondary antibody, use and choice of blocking solutions, washing buffers, and antifading mounting medium. The several steps of the procedure must be carefully performed in order to avoid the formation of false positive fluorescent artifacts. The quality control of the assay involves the use of serum standards for negative, low positive and strongly positive reaction in each run of the assay. In addition, every new lot or new brand of HEp-2 slides should be evaluated by using a panel of standard sera yielding the most relevant AC patterns. Special attention should be dedicated to the training of personnel for the analysis of the slides at the microscope. These should be able to identify possible artifacts, recognize all relevant AC patterns, and formulate possible reflex tests according to the observed AC patterns.
Collapse
|
20
|
Yamada M, Funaki S, Miki S. Formaldehyde interacts with RNA rather than DNA: Accumulation of formaldehyde by the RNA-inorganic hybrid material. Int J Biol Macromol 2019; 122:168-173. [DOI: 10.1016/j.ijbiomac.2018.10.159] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 09/30/2018] [Accepted: 10/23/2018] [Indexed: 11/28/2022]
|
21
|
Carlsson J, Davidsson S, Fridfeldt J, Giunchi F, Fiano V, Grasso C, Zelic R, Richiardi L, Andrén O, Pettersson A, Fiorentino M, Akre O. Quantity and quality of nucleic acids extracted from archival formalin fixed paraffin embedded prostate biopsies. BMC Med Res Methodol 2018; 18:161. [PMID: 30518332 PMCID: PMC6280346 DOI: 10.1186/s12874-018-0628-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 11/26/2018] [Indexed: 01/10/2023] Open
Abstract
Background In Sweden, human tissue samples obtained from diagnostic and surgical procedures have for decades been routinely stored in a formalin-fixed, paraffin-embedded, form. Through linkage with nationwide registers, these samples are available for molecular studies to identify biomarkers predicting mortality even in slow-progressing prostate cancer. However, tissue fixation causes modifications of nucleic acids, making it challenging to extract high-quality nucleic acids from formalin fixated tissues. Methods In this study, the efficiency of five commercial nucleic acid extraction kits was compared on 30 prostate biopsies with normal histology, and the quantity and quality of the products were compared using spectrophotometry and Agilent’s BioAnalyzer. Student’s t-test’s and Bland-Altman analyses were performed in order to investigate differences in nucleic acid quantity and quality between the five kits. The best performing extraction kits were subsequently tested on an additional 84 prostate tumor tissues. A Spearman’s correlation test and linear regression analyses were performed in order to investigate the impact of tissue age and amount of tissue on nucleic acid quantity and quality. Results Nucleic acids extracted with RNeasy® FFPE and QIAamp® DNA FFPE Tissue kit had the highest quantity and quality, and was used for extraction from 84 tumor tissues. Nucleic acids were successfully extracted from all biopsies, and the amount of tumor (in millimeter) was found to have the strongest association with quantity and quality of nucleic acids. Conclusions To conclude, this study shows that the choice of nucleic acid extraction kit affects the quantity and quality of extracted products. Furthermore, we show that extraction of nucleic acids from archival formalin-fixed prostate biopsies is possible, allowing molecular studies to be performed on this valuable sample collection.
Collapse
Affiliation(s)
- Jessica Carlsson
- Department of Urology, Faculty of Medicine and Health, University Hospital in Örebro, Örebro University, Södra Grevrosengatan, 70185, Örebro, Sweden.
| | - Sabina Davidsson
- Department of Urology, Faculty of Medicine and Health, University Hospital in Örebro, Örebro University, Södra Grevrosengatan, 70185, Örebro, Sweden
| | - Jonna Fridfeldt
- Department of Urology, Faculty of Medicine and Health, University Hospital in Örebro, Örebro University, Södra Grevrosengatan, 70185, Örebro, Sweden
| | - Francesca Giunchi
- Department of Pathology, F. Addari Institute of Oncology S. Orsola Hospital, Bologna, Italy
| | - Valentina Fiano
- Cancer Epidemiology Unit-CERMS, Department of Medical Sciences, University of Turin and CPO-Piemonte, Turin, Italy
| | - Chiara Grasso
- Cancer Epidemiology Unit-CERMS, Department of Medical Sciences, University of Turin and CPO-Piemonte, Turin, Italy
| | - Renata Zelic
- Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden
| | - Lorenzo Richiardi
- Cancer Epidemiology Unit-CERMS, Department of Medical Sciences, University of Turin and CPO-Piemonte, Turin, Italy
| | - Ove Andrén
- Department of Urology, Faculty of Medicine and Health, University Hospital in Örebro, Örebro University, Södra Grevrosengatan, 70185, Örebro, Sweden
| | - Andreas Pettersson
- Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institute, Stockholm, Sweden
| | | | - Olof Akre
- Department of Medicine Solna, Karolinska Institute, and Department of Urology, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
22
|
Amatori S, Persico G, Paolicelli C, Hillje R, Sahnane N, Corini F, Furlan D, Luzi L, Minucci S, Giorgio M, Pelicci PG, Fanelli M. Epigenomic profiling of archived FFPE tissues by enhanced PAT-ChIP (EPAT-ChIP) technology. Clin Epigenetics 2018; 10:143. [PMID: 30446010 PMCID: PMC6240272 DOI: 10.1186/s13148-018-0576-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 10/29/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The introduction of pathology tissue-chromatin immunoprecipitation (PAT-ChIP), a technique allowing chromatin immunoprecipitation (ChIP) from formalin-fixed paraffin-embedded (FFPE) tissues, has extended the application of chromatin studies to clinical patient samples. However, extensive crosslinking introduced during routine tissue fixation of clinical specimens may hamper the application of PAT-ChIP to genome-wide studies (PAT-ChIP-Seq) from archived tissue samples. The reduced efficiency in chromatin extraction from over-fixed formalin archival samples is the main hurdle to overcome, especially when low abundant epigenetic marks (e.g., H3K4me3) are investigated. RESULTS We evaluated different modifications of the original PAT-ChIP protocol to improve chromatin isolation from FFPE tissues. With this aim, we first made extensive usage of a normal human colon specimen fixed at controlled conditions (24 h, 48 h, and 72 h) to mimic the variability of tissue fixation that is most frequently found in archived samples. Different conditions of chromatin extraction were tested applying either diverse sonication protocols or heat-mediated limited reversal of crosslinking (LRC). We found that, if compared with canonical PAT-ChIP protocol, LRC strongly increases chromatin extraction efficiency, especially when 72-h fixed FFPE samples are used. The new procedure, that we named enhanced PAT-ChIP (EPAT-ChIP), was then applied at genome-wide level using an archival sample of invasive breast carcinoma to investigate H3K4me3, a lowly abundant histone modification, and H3K27me3 and H3K27ac, two additional well-known histone marks. CONCLUSIONS EPAT-ChIP procedure improves the efficiency of chromatin isolation from FFPE samples allowing the study of long time-fixed specimens (72 h), as well as the investigation of low distributed epigenetic marks (e.g., H3K4me3) and the analysis of multiple histone marks from low amounts of starting material. We believe that EPAT-ChIP will facilitate the application of chromatin studies to archived pathology samples, thus contributing to extend the current understanding of cancer epigenomes and enabling the identification of clinically useful tumor biomarkers.
Collapse
Affiliation(s)
- Stefano Amatori
- Department of Biomolecular Sciences, Molecular Pathology Laboratory "PaoLa", University of Urbino "Carlo Bo", Via Arco d'Augusto 2, 61032, Fano, PU, Italy.,Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Giuseppe Persico
- Department of Biomolecular Sciences, Molecular Pathology Laboratory "PaoLa", University of Urbino "Carlo Bo", Via Arco d'Augusto 2, 61032, Fano, PU, Italy
| | - Claudio Paolicelli
- Department of Biomolecular Sciences, Molecular Pathology Laboratory "PaoLa", University of Urbino "Carlo Bo", Via Arco d'Augusto 2, 61032, Fano, PU, Italy
| | - Roman Hillje
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Nora Sahnane
- Unit of Pathology, Department of Medicine and Surgery, University of Insubria, Via O. Rossi 9, 21100, Varese, Italy
| | - Francesco Corini
- U.O.C. Anatomia Patologica, "C. G. Mazzoni" Hospital, Via degli Iris 2, 63100, Ascoli Piceno, Italy
| | - Daniela Furlan
- Unit of Pathology, Department of Medicine and Surgery, University of Insubria, Via O. Rossi 9, 21100, Varese, Italy
| | - Lucilla Luzi
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Saverio Minucci
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Marco Giorgio
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Pier Giuseppe Pelicci
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, 20139, Milan, Italy
| | - Mirco Fanelli
- Department of Biomolecular Sciences, Molecular Pathology Laboratory "PaoLa", University of Urbino "Carlo Bo", Via Arco d'Augusto 2, 61032, Fano, PU, Italy.
| |
Collapse
|
23
|
Lu XJD, Liu KYP, Zhu YS, Cui C, Poh CF. Using ddPCR to assess the DNA yield of FFPE samples. BIOMOLECULAR DETECTION AND QUANTIFICATION 2018; 16:5-11. [PMID: 30560062 PMCID: PMC6287546 DOI: 10.1016/j.bdq.2018.10.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 10/04/2018] [Accepted: 10/24/2018] [Indexed: 12/24/2022]
Abstract
Objectives Detection of genomic alterations in diseases can be achieved with current molecular technologies. However, the molecules extracted from formalin-fixed, paraffin-embedded (FFPE) bio-samples are often limited possibly due to DNA fragmentation and crosslinking caused by the sample fixation and processing. The study objective was to design a droplet digital PCR (ddPCR) assay to assess the quality and quantity of DNA derived from various DNA extraction conditions on FFPE samples. Methods We used 10 μm-thick sections from 5 FFPE oral tumoral blocks, each consisting of 10–15 sections. The protocol variables tested included: 1) tissue staining; 2) duration and 3) temperature of post-digestion heat treatment; and 4) DNA extraction method. DNA quantity was assessed using the NanoDrop 2000 (Thermo Fisher Scientific, USA), the Qubit fluorometer (Thermo Fisher Scientific, USA), and a ddPCR-based assay. DNA quality was assessed using a ddPCR assay for the degree of fragmentation and the effectiveness of removing crosslinks with varying guanine-cytosine (GC)-content. Results Deparaffinization with xylene helped to increase the DNA yield. Tissue staining (methyl green staining, pH 6) prior to microdissection, comparing to no staining, caused additional DNA fragmentation. Compared to column-based method, DNA extracted with phenol chloroform and ethanol precipitation increased the degree of fragmentation and lowered the yield of amplifiable DNA. The cross-linking derived from GC-contents may not be the only factor impacting on the DNA quality. Conclusions Samples undergoing different pre-treatment conditions prior to extraction can impact the yield of amplifiable DNA. Our ddPCR assay can be used to assess for both DNA quantity and quality.
Collapse
Affiliation(s)
- X J David Lu
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.,Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, BC, V5Z 1L3, Canada
| | - Kelly Y P Liu
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.,Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, BC, V5Z 1L3, Canada
| | - Yuqi Sarah Zhu
- Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, BC, V5Z 1L3, Canada
| | - Cindy Cui
- Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, BC, V5Z 1L3, Canada
| | - Catherine F Poh
- Department of Oral Biological and Medical Sciences, Faculty of Dentistry, University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.,Department of Integrative Oncology, British Columbia Cancer Research Centre, Vancouver, BC, V5Z 1L3, Canada.,Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, V6T 2B5, Canada
| |
Collapse
|
24
|
Sutherland JH, Holloman WK. Loss of Cohesin Subunit Rec8 Switches Rad51 Mediator Dependence in Resistance to Formaldehyde Toxicity in Ustilago maydis. Genetics 2018; 210:559-572. [PMID: 30082279 PMCID: PMC6216591 DOI: 10.1534/genetics.118.301439] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 08/03/2018] [Indexed: 01/08/2023] Open
Abstract
DNA-protein cross-links (DPCs) are frequently occurring lesions that provoke continual threats to the integrity of the genome by interference with replication and transcription. Reactive aldehydes generated from endogenous metabolic processes or produced in the environment are sources that trigger cross-linking of DNA with associated proteins. DNA repair pathways in place for removing DPCs, or for bypassing them to enable completion of replication, include homologous recombination (HR) and replication fork remodeling (FR) systems. Here, we surveyed a set of mutants defective in known HR and FR components to determine their contribution toward maintaining resistance to chronic formaldehyde (FA) exposure in Ustilago maydis, a fungus that relies on the BRCA2-family member Brh2 as the principal Rad51 mediator in repair of DNA strand breaks. We found that, in addition to Brh2, Rad52 was also vital for resistance to FA. Deleting the gene for Rec8, a kleisin subunit of cohesin, eliminated the requirement for Brh2, but not Rad52, in FA resistance. The Rad51K133R mutant variant that is able to bind DNA but unable to dissociate from it was able to support resistance to FA. These findings suggest a model for DPC repair and tolerance that features a specialized role for Rad52, enabling Rad51 to access DNA in its noncanonical capacity of replication fork protection rather than DNA strand transfer.
Collapse
Affiliation(s)
- Jeanette H Sutherland
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York 10065
| | - William K Holloman
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York 10065
| |
Collapse
|
25
|
Shishodia S, Zhang D, El-Sagheer AH, Brown T, Claridge TDW, Schofield CJ, Hopkinson RJ. NMR analyses on N-hydroxymethylated nucleobases - implications for formaldehyde toxicity and nucleic acid demethylases. Org Biomol Chem 2018; 16:4021-4032. [PMID: 29767200 PMCID: PMC5977384 DOI: 10.1039/c8ob00734a] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 03/29/2018] [Indexed: 12/14/2022]
Abstract
Formaldehyde is produced in cells by enzyme-catalysed demethylation reactions, including those occurring on N-methylated nucleic acids. Formaldehyde reacts with nucleobases to form N-hydroxymethylated adducts that may contribute to its toxicity/carcinogenicity when added exogenously, but the chemistry of these reactions has been incompletely defined. We report NMR studies on the reactions of formaldehyde with canonical/modified nucleobases. The results reveal that hydroxymethyl hemiaminals on endocyclic nitrogens, as observed with thymidine and uridine monophosphates, are faster to form than equivalent hemiaminals on exocyclic nitrogens; however, the exocyclic adducts, as formed with adenine, guanine and cytosine, are more stable in solution. Nucleic acid demethylase (FTO)-catalysed hydroxylation of (6-methyl)adenosine results in (6-hydroxymethyl)adenosine as the major observed product; by contrast no evidence for a stable 3-hydroxymethyl adduct was accrued with FTO-catalysed oxidation of (3-methyl)thymidine. Collectively, our results imply N-hydroxymethyled adducts of nucleic acid bases, formed either by reactions with formaldehyde or via demethylase catalysis, have substantially different stabilities, with some being sufficiently stable to have functional roles in disease or the regulation of nucleic acid/nucleobase activity.
Collapse
Affiliation(s)
- S. Shishodia
- Chemistry Research Laboratory
,
12 Mansfield Road
, Oxford
, OX1 3TA
, UK
| | - D. Zhang
- Chemistry Research Laboratory
,
12 Mansfield Road
, Oxford
, OX1 3TA
, UK
| | - A. H. El-Sagheer
- Chemistry Research Laboratory
,
12 Mansfield Road
, Oxford
, OX1 3TA
, UK
- Chemistry Branch, Department of Science and Mathematics
, Faculty of Petroleum and Mining Engineering
, Suez University
,
43721 Suez
, Egypt
| | - T. Brown
- Chemistry Research Laboratory
,
12 Mansfield Road
, Oxford
, OX1 3TA
, UK
| | - T. D. W. Claridge
- Chemistry Research Laboratory
,
12 Mansfield Road
, Oxford
, OX1 3TA
, UK
| | - C. J. Schofield
- Chemistry Research Laboratory
,
12 Mansfield Road
, Oxford
, OX1 3TA
, UK
| | - R. J. Hopkinson
- Chemistry Research Laboratory
,
12 Mansfield Road
, Oxford
, OX1 3TA
, UK
- Leicester Institute of Structural and Chemical Biology and Department of Chemistry
, University of Leicester
,
Henry Wellcome Building
, Lancaster Road
, Leicester
, LE1 7RH
, UK
.
| |
Collapse
|
26
|
Single-strand DNA library preparation improves sequencing of formalin-fixed and paraffin-embedded (FFPE) cancer DNA. Oncotarget 2018; 7:59115-59128. [PMID: 27463017 PMCID: PMC5312299 DOI: 10.18632/oncotarget.10827] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/30/2016] [Indexed: 12/23/2022] Open
Abstract
DNA derived from formalin-fixed and paraffin-embedded (FFPE) tissue has been a challenge to large-scale genomic sequencing, due to its low quality and quantities. Improved techniques enabling the genome-wide analysis of FFPE material would be of great value, both from a research and clinical perspective. Comparing a single-strand DNA library preparation method originally developed for ancient DNA to conventional protocols using double-stranded DNA derived from FFPE material we obtain on average 900-fold more library molecules and improved sequence complexity from as little as 5 ng input DNA. FFPE DNA is highly fragmented, usually below 100bp, and up to 60% of reads start after or end prior to adenine residues, suggesting that crosslinks predominate at adenine residues. Similar to ancient DNA, C > T substitutions are slightly increased with maximum rates up to 3% at the ends of molecules. In whole exome sequencing of single-strand libraries from lung, breast, colorectal, prostate and skin cancers we identify known cancer mutations. In summary, we show that single-strand library preparation enables genomic sequencing, even from low amounts of degraded FFPE DNA. This method provides a clear advantage both in research and clinical settings, where FFPE material (e.g. from biopsies) often is the only source of DNA available. Improving the genetic characterization that can be performed on conventional archived FFPE tissue, the single-strand library preparation allows scarce samples to be used in personalized medicine and enables larger sample sizes in future sequencing studies.
Collapse
|
27
|
Zaidi H, Hoffman EA, Shetty SJ, Bekiranov S, Auble DT. Second-generation method for analysis of chromatin binding with formaldehyde-cross-linking kinetics. J Biol Chem 2017; 292:19338-19355. [PMID: 28972159 DOI: 10.1074/jbc.m117.796441] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 09/21/2017] [Indexed: 11/06/2022] Open
Abstract
Formaldehyde-cross-linking underpins many of the most commonly used experimental approaches in the chromatin field, especially in capturing site-specific protein-DNA interactions. Extending such assays to assess the stability and binding kinetics of protein-DNA interactions is more challenging, requiring absolute measurements with a relatively high degree of physical precision. We previously described an experimental framework called the cross-linking kinetics (CLK) assay, which uses time-dependent formaldehyde-cross-linking data to extract kinetic parameters of chromatin binding. Many aspects of formaldehyde behavior in cells are unknown or undocumented, however, and could potentially affect CLK data analyses. Here, we report biochemical results that better define the properties of formaldehyde-cross-linking in budding yeast cells. These results have the potential to inform interpretations of "standard" chromatin assays, including chromatin immunoprecipitation. Moreover, the chemical complexity we uncovered resulted in the development of an improved method for measuring binding kinetics with the CLK approach. Optimum conditions included an increased formaldehyde concentration and more robust glycine-quench conditions. Notably, we observed that formaldehyde-cross-linking rates can vary dramatically for different protein-DNA interactions in vivo Some interactions were cross-linked much faster than the in vivo macromolecular interactions, making them suitable for kinetic analysis. For other interactions, we found the cross-linking reaction occurred on the same time scale or slower than binding dynamics; for these interactions, it was sometimes possible to compute the in vivo equilibrium-binding constant but not binding on- and off-rates. This improved method yields more accurate in vivo binding kinetics estimates on the minute time scale.
Collapse
Affiliation(s)
- Hussain Zaidi
- From the School of Medicine Research Computing, University of Virginia and
| | - Elizabeth A Hoffman
- the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Savera J Shetty
- the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - Stefan Bekiranov
- the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| | - David T Auble
- the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908
| |
Collapse
|
28
|
Majikes JM, Nash JA, LaBean TH. Search for effective chemical quenching to arrest molecular assembly and directly monitor DNA nanostructure formation. NANOSCALE 2017; 9:1637-1644. [PMID: 28074960 DOI: 10.1039/c6nr08433h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Structural DNA nanotechnology has demonstrated both versatility and potential as a molecular manufacturing tool; the formation and processing of DNA nanostructures has therefore been subject to much interest. Characterization of the formation process itself is vital to understanding the role of design in production yield. We present our search for a robust new technique, chemical quenching, to arrest molecular folding in DNA systems for subsequent characterization. Toward this end we will introduce two miniM13 origami designs based on a 2.4 kb scaffold, each with diametrically opposed scaffold routing strategies (maximized scaffold crossovers versus maximized staple crossovers) to examine the relevance of design in the folding process. By chemically rendering single strand DNA inert and unable to hybridize, we probe the folding pathway of several scaffolded DNA origami structures.
Collapse
Affiliation(s)
- J M Majikes
- Department of Materials Science & Engineering, North Carolina State University, Raleigh, North Carolina 27606, USA.
| | - J A Nash
- Department of Materials Science & Engineering, North Carolina State University, Raleigh, North Carolina 27606, USA.
| | - T H LaBean
- Department of Materials Science & Engineering, North Carolina State University, Raleigh, North Carolina 27606, USA.
| |
Collapse
|
29
|
The excluded DNA strand is SEW important for hexameric helicase unwinding. Methods 2016; 108:79-91. [DOI: 10.1016/j.ymeth.2016.04.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/07/2016] [Accepted: 04/07/2016] [Indexed: 02/04/2023] Open
|
30
|
von Hippel PH, Johnson NP, Marcus AH. Fifty years of DNA "breathing": Reflections on old and new approaches. Biopolymers 2016; 99:923-54. [PMID: 23840028 DOI: 10.1002/bip.22347] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 07/02/2013] [Indexed: 12/20/2022]
Abstract
The coding sequences for genes, and much other regulatory information involved in genome expression, are located 'inside' the DNA duplex. Thus the "macromolecular machines" that read-out this information from the base sequence of the DNA must somehow access the DNA "interior." Double-stranded (ds) DNA is a highly structured and cooperatively stabilized system at physiological temperatures, but is also only marginally stable and undergoes a cooperative "melting phase transition" at temperatures not far above physiological. Furthermore, due to its length and heterogeneous sequence, with AT-rich segments being less stable than GC-rich segments, the DNA genome 'melts' in a multistate fashion. Therefore the DNA genome must also manifest thermally driven structural ("breathing") fluctuations at physiological temperatures that should reflect the heterogeneity of the dsDNA stability near the melting temperature. Thus many of the breathing fluctuations of dsDNA are likely also to be sequence dependent, and could well contain information that should be "readable" and useable by regulatory proteins and protein complexes in site-specific binding reactions involving dsDNA "opening." Our laboratory has been involved in studying the breathing fluctuations of duplex DNA for about 50 years. In this "Reflections" article we present a relatively chronological overview of these studies, starting with the use of simple chemical probes (such as hydrogen exchange, formaldehyde, and simple DNA "melting" proteins) to examine the local stability of the dsDNA structure, and culminating in sophisticated spectroscopic approaches that can be used to monitor the breathing-dependent interactions of regulatory complexes with their duplex DNA targets in "real time."
Collapse
Affiliation(s)
- Peter H von Hippel
- Institute of Molecular Biology, University of Oregon, Eugene, OR, 97403; Department of Chemistry, University of Oregon, Eugene, OR, 97403
| | | | | |
Collapse
|
31
|
Piskorz AM, Ennis D, Macintyre G, Goranova TE, Eldridge M, Segui-Gracia N, Valganon M, Hoyle A, Orange C, Moore L, Jimenez-Linan M, Millan D, McNeish IA, Brenton JD. Methanol-based fixation is superior to buffered formalin for next-generation sequencing of DNA from clinical cancer samples. Ann Oncol 2016; 27:532-9. [PMID: 26681675 PMCID: PMC4769995 DOI: 10.1093/annonc/mdv613] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 10/29/2015] [Accepted: 12/01/2015] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Next-generation sequencing (NGS) of tumour samples is a critical component of personalised cancer treatment, but it requires high-quality DNA samples. Routine neutral-buffered formalin (NBF) fixation has detrimental effects on nucleic acids, causing low yields, as well as fragmentation and DNA base changes, leading to significant artefacts. PATIENTS AND METHODS We have carried out a detailed comparison of DNA quality from matched samples isolated from high-grade serous ovarian cancers from 16 patients fixed in methanol and NBF. These experiments use tumour fragments and mock biopsies to simulate routine practice, ensuring that results are applicable to standard clinical biopsies. RESULTS Using matched snap-frozen tissue as gold standard comparator, we show that methanol-based fixation has significant benefits over NBF, with greater DNA yield, longer fragment size and more accurate copy-number calling using shallow whole-genome sequencing (WGS). These data also provide a new approach to understand and quantify artefactual effects of fixation using non-negative matrix factorisation to analyse mutational spectra from targeted and WGS data. CONCLUSION We strongly recommend the adoption of methanol fixation for sample collection strategies in new clinical trials. This approach is immediately available, is logistically simple and can offer cheaper and more reliable mutation calling than traditional NBF fixation.
Collapse
Affiliation(s)
- A M Piskorz
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge
| | - D Ennis
- Institute of Cancer Sciences, University of Glasgow, Glasgow
| | - G Macintyre
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge
| | - T E Goranova
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge
| | - M Eldridge
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge
| | - N Segui-Gracia
- Cancer Molecular Diagnostics Laboratory, Department of Oncology, University of Cambridge, Cambridge
| | - M Valganon
- Cancer Molecular Diagnostics Laboratory, Department of Oncology, University of Cambridge, Cambridge
| | - A Hoyle
- Department of Pathology, Queen Elizabeth University Hospital, Glasgow
| | - C Orange
- Institute of Cancer Sciences, University of Glasgow, Glasgow
| | - L Moore
- Addenbrooke's Hospital, Cambridge University Hospital NHS Foundation Trust and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Department of Histopathology, Addenbrooke's Hospital, Cambridge, UK
| | - M Jimenez-Linan
- Addenbrooke's Hospital, Cambridge University Hospital NHS Foundation Trust and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge Department of Histopathology, Addenbrooke's Hospital, Cambridge, UK
| | - D Millan
- Department of Pathology, Queen Elizabeth University Hospital, Glasgow
| | - I A McNeish
- Institute of Cancer Sciences, University of Glasgow, Glasgow
| | - J D Brenton
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge Addenbrooke's Hospital, Cambridge University Hospital NHS Foundation Trust and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge
| |
Collapse
|
32
|
Gullapalli RP, Mazzitelli CL. Polyethylene glycols in oral and parenteral formulations—A critical review. Int J Pharm 2015; 496:219-39. [DOI: 10.1016/j.ijpharm.2015.11.015] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 11/05/2015] [Accepted: 11/08/2015] [Indexed: 10/22/2022]
|
33
|
Hoffman EA, Frey BL, Smith LM, Auble DT. Formaldehyde crosslinking: a tool for the study of chromatin complexes. J Biol Chem 2015; 290:26404-11. [PMID: 26354429 DOI: 10.1074/jbc.r115.651679] [Citation(s) in RCA: 236] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Formaldehyde has been used for decades to probe macromolecular structure and function and to trap complexes, cells, and tissues for further analysis. Formaldehyde crosslinking is routinely employed for detection and quantification of protein-DNA interactions, interactions between chromatin proteins, and interactions between distal segments of the chromatin fiber. Despite widespread use and a rich biochemical literature, important aspects of formaldehyde behavior in cells have not been well described. Here, we highlight features of formaldehyde chemistry relevant to its use in analyses of chromatin complexes, focusing on how its properties may influence studies of chromatin structure and function.
Collapse
Affiliation(s)
- Elizabeth A Hoffman
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908 and
| | - Brian L Frey
- the Department of Chemistry and Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin 53706
| | - Lloyd M Smith
- the Department of Chemistry and Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin 53706
| | - David T Auble
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908 and
| |
Collapse
|
34
|
Organocatalytic removal of formaldehyde adducts from RNA and DNA bases. Nat Chem 2015; 7:752-8. [PMID: 26291948 PMCID: PMC4545578 DOI: 10.1038/nchem.2307] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 06/22/2015] [Indexed: 01/04/2023]
Abstract
Formaldehyde is universally employed to fix tissue specimens, where it forms hemiaminal and aminal adducts with biomolecules, hindering the ability to retrieve molecular information. Common methods for removing these adducts involve extended heating, which can cause extensive degradation of nucleic acids, particularly RNA. Here we show that water-soluble bifunctional catalysts (anthranilates and phosphanilates) speed the reversal of formaldehyde adducts of mononucleotides over standard buffers. Studies with formaldehyde-treated RNA oligonucleotides show that the catalysts enhance adduct removal, restoring unmodified RNA at 37 °C even when extensively modified, and avoiding high temperatures that promote RNA degradation. Experiments with formalin-fixed, paraffin-embedded cell samples show that the catalysis is compatible with common RNA extraction protocols, with detectable RNA yields increased by 1.5–2.4 fold using a catalyst under optimized conditions, and by 7–25 fold compared to a commercial kit. Such catalytic strategies show promise for general use in reversing formaldehyde adducts in clinical specimens.
Collapse
|
35
|
Miles G, Rae J, Ramalingam SS, Pfeifer J. Genetic Testing and Tissue Banking for Personalized Oncology: Analytical and Institutional Factors. Semin Oncol 2015; 42:713-23. [PMID: 26433552 DOI: 10.1053/j.seminoncol.2015.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Personalized oncology, or more aptly precision oncogenomics, refers to the identification and implementation of clinically actionable targets tailored to an individual patient's cancer genomic information. Banking of human tissue and other biospecimens establishes a framework to extract and collect the data essential to our understanding of disease pathogenesis and treatment. Cancer cooperative groups in the United States have led the way in establishing robust biospecimen collection mechanisms to facilitate translational research, and combined with technological advances in molecular testing, tissue banking has expanded from its traditional base in academic research and is assuming an increasingly pivotal role in directing the clinical care of cancer patients. Comprehensive screening of tumors by DNA sequencing and the ability to mine and interpret these large data sets from well-organized tissue banks have defined molecular subtypes of cancer. Such stratification by genomic criteria has revolutionized our perspectives on cancer diagnosis and treatment, offering insight into prognosis, progression, and susceptibility or resistance to known therapeutic agents. In turn, this has enabled clinicians to offer treatments tailored to patients that can greatly improve their chances of survival. Unique challenges and opportunities accompany the rapidly evolving interplay between tissue banking and genomic sequencing, and are the driving forces underlying the revolution in precision medicine. Molecular testing and precision medicine clinical trials are now becoming the major thrust behind the cooperative groups' clinical research efforts.
Collapse
Affiliation(s)
- George Miles
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO.
| | - James Rae
- Department of Internal Medicine & Pharmacology, University of Michigan, Ann Arbor, MI
| | - Suresh S Ramalingam
- Department of Hematology and Medical Oncology, Emory School of Medicine, Winship Cancer Institute, Atlanta, GA
| | - John Pfeifer
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO
| |
Collapse
|
36
|
Catalano MJ, Liu S, Andersen N, Yang Z, Johnson KM, Price NE, Wang Y, Gates KS. Chemical structure and properties of interstrand cross-links formed by reaction of guanine residues with abasic sites in duplex DNA. J Am Chem Soc 2015; 137:3933-45. [PMID: 25710271 DOI: 10.1021/jacs.5b00669] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A new type of interstrand cross-link resulting from the reaction of a DNA abasic site with a guanine residue on the opposing strand of the double helix was recently identified, but the chemical connectivity of the cross-link was not rigorously established. The work described here was designed to characterize the chemical structure and properties of dG-AP cross-links generated in duplex DNA. The approach involved characterization of the nucleoside cross-link "remnant" released by enzymatic digestion of DNA duplexes containing the dG-AP cross-link. We first carried out a chemical synthesis and complete spectroscopic structure determination of the putative cross-link remnant 9b composed of a 2-deoxyribose adduct attached to the exocyclic N(2)-amino group of dG. A reduced analogue of the cross-link remnant was also prepared (11b). Liquid chromatography-tandem mass spectrometric (LC-MS/MS) analysis revealed that the retention times and mass spectral properties of synthetic standards 9b and 11b matched those of the authentic cross-link remnants released by enzymatic digestion of duplexes containing the native and reduced dG-AP cross-link, respectively. These results establish the chemical connectivity of the dG-AP cross-link released from duplex DNA and provide a foundation for detection of this lesion in biological samples. The dG-AP cross-link in duplex DNA was remarkably stable, decomposing with a half-life of 22 days at pH 7 and 23 °C. The intrinsic chemical stability of the dG-AP cross-link suggests that this lesion in duplex DNA may have the power to block DNA-processing enzymes involved in transcription and replication.
Collapse
Affiliation(s)
| | - Shuo Liu
- ‡Environmental Toxicology Graduate Program and Department of Chemistry, University of California-Riverside, Riverside, California 92521-0403, United States
| | - Nisana Andersen
- ‡Environmental Toxicology Graduate Program and Department of Chemistry, University of California-Riverside, Riverside, California 92521-0403, United States
| | | | | | | | - Yinsheng Wang
- ‡Environmental Toxicology Graduate Program and Department of Chemistry, University of California-Riverside, Riverside, California 92521-0403, United States
| | | |
Collapse
|
37
|
Takahashi JS, Kumar V, Nakashe P, Koike N, Huang HC, Green CB, Kim TK. ChIP-seq and RNA-seq methods to study circadian control of transcription in mammals. Methods Enzymol 2014; 551:285-321. [PMID: 25662462 DOI: 10.1016/bs.mie.2014.10.059] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Genome-wide analyses have revolutionized our ability to study the transcriptional regulation of circadian rhythms. The advent of next-generation sequencing methods has facilitated the use of two such technologies, ChIP-seq and RNA-seq. In this chapter, we describe detailed methods and protocols for these two techniques, with emphasis on their usage in circadian rhythm experiments in the mouse liver, a major target organ of the circadian clock system. Critical factors for these methods are highlighted and issues arising with time series samples for ChIP-seq and RNA-seq are discussed. Finally, detailed protocols for library preparation suitable for Illumina sequencing platforms are presented.
Collapse
Affiliation(s)
- Joseph S Takahashi
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
| | - Vivek Kumar
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Prachi Nakashe
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Nobuya Koike
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Hung-Chung Huang
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Carla B Green
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Tae-Kyung Kim
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
38
|
Rhee HS, Bataille AR, Zhang L, Pugh BF. Subnucleosomal structures and nucleosome asymmetry across a genome. Cell 2014; 159:1377-88. [PMID: 25480300 PMCID: PMC4258235 DOI: 10.1016/j.cell.2014.10.054] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/19/2014] [Accepted: 10/13/2014] [Indexed: 10/24/2022]
Abstract
Genes are packaged into nucleosomal arrays, each nucleosome typically having two copies of histones H2A, H2B, H3, and H4. Histones have distinct posttranslational modifications, variant isoforms, and dynamics. Whether each histone copy within a nucleosome has distinct properties, particularly in relation to the direction of transcription, is unknown. Here we use chromatin immunoprecipitation-exonuclease (ChIP-exo) to resolve the organization of individual histones on a genomic scale. We detect widespread subnucleosomal structures in dynamic chromatin, including what appear to be half-nucleosomes consisting of one copy of each histone. We also detect interactions of H3 tails with linker DNA between nucleosomes, which may be negatively regulated by methylation of H3K36. Histone variant H2A.Z is enriched on the promoter-distal half of the +1 nucleosome, whereas H2BK123 ubiquitylation and H3K9 acetylation are enriched on the promoter-proximal half in a transcription-linked manner. Subnucleosome asymmetries might serve as molecular beacons that guide transcription.
Collapse
Affiliation(s)
- Ho Sung Rhee
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Alain R Bataille
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Liye Zhang
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - B Franklin Pugh
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
| |
Collapse
|
39
|
Viswanathan R, Hoffman EA, Shetty SJ, Bekiranov S, Auble DT. Analysis of chromatin binding dynamics using the crosslinking kinetics (CLK) method. Methods 2014; 70:97-107. [PMID: 25448301 PMCID: PMC4267959 DOI: 10.1016/j.ymeth.2014.10.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Revised: 10/17/2014] [Accepted: 10/27/2014] [Indexed: 02/03/2023] Open
Abstract
Transcription factor binding sites in chromatin are routinely inventoried by the chromatin immunoprecipitation assay, and these binding patterns can provide precise and detailed information about cell state. However, some fundamental molecular questions regarding transcription factor function require an understanding of in vivo binding dynamics as well as location information. Here we describe the crosslinking kinetics (CLK) assay, in which the time-dependence of formaldehyde crosslinking is used to extract on- and off-rates for chromatin binding in vivo.
Collapse
Affiliation(s)
- Ramya Viswanathan
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, United States
| | - Elizabeth A Hoffman
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, United States
| | - Savera J Shetty
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, United States
| | - Stefan Bekiranov
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, United States
| | - David T Auble
- Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, United States.
| |
Collapse
|
40
|
Nakamura J, Mutlu E, Sharma V, Collins L, Bodnar W, Yu R, Lai Y, Moeller B, Lu K, Swenberg J. The endogenous exposome. DNA Repair (Amst) 2014; 19:3-13. [PMID: 24767943 PMCID: PMC4097170 DOI: 10.1016/j.dnarep.2014.03.031] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The concept of the Exposome is a compilation of diseases and one's lifetime exposure to chemicals, whether the exposure comes from environmental, dietary, or occupational exposures; or endogenous chemicals that are formed from normal metabolism, inflammation, oxidative stress, lipid peroxidation, infections, and other natural metabolic processes such as alteration of the gut microbiome. In this review, we have focused on the endogenous exposome, the DNA damage that arises from the production of endogenous electrophilic molecules in our cells. It provides quantitative data on endogenous DNA damage and its relationship to mutagenesis, with emphasis on when exogenous chemical exposures that produce identical DNA adducts to those arising from normal metabolism cause significant increases in total identical DNA adducts. We have utilized stable isotope labeled chemical exposures of animals and cells, so that accurate relationships between endogenous and exogenous exposures can be determined. Advances in mass spectrometry have vastly increased both the sensitivity and accuracy of such studies. Furthermore, we have clear evidence of which sources of exposure drive low dose biology that results in mutations and disease. These data provide much needed information to impact quantitative risk assessments, in the hope of moving towards the use of science, rather than default assumptions.
Collapse
Affiliation(s)
- Jun Nakamura
- University of North Carolina, Chapel Hill, NC, United States
| | - Esra Mutlu
- University of North Carolina, Chapel Hill, NC, United States
| | - Vyom Sharma
- University of North Carolina, Chapel Hill, NC, United States
| | - Leonard Collins
- University of North Carolina, Chapel Hill, NC, United States
| | - Wanda Bodnar
- University of North Carolina, Chapel Hill, NC, United States
| | - Rui Yu
- University of North Carolina, Chapel Hill, NC, United States
| | - Yongquan Lai
- University of North Carolina, Chapel Hill, NC, United States
| | - Benjamin Moeller
- University of North Carolina, Chapel Hill, NC, United States; Lovelace Respiratory Research Institute, Albuquerque, NM, United States
| | - Kun Lu
- University of North Carolina, Chapel Hill, NC, United States
| | - James Swenberg
- University of North Carolina, Chapel Hill, NC, United States.
| |
Collapse
|
41
|
Van Simaeys D, Turek D, Champanhac C, Vaizer J, Sefah K, Zhen J, Sutphen R, Tan W. Identification of cell membrane protein stress-induced phosphoprotein 1 as a potential ovarian cancer biomarker using aptamers selected by cell systematic evolution of ligands by exponential enrichment. Anal Chem 2014; 86:4521-7. [PMID: 24654750 PMCID: PMC4018121 DOI: 10.1021/ac500466x] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 03/21/2014] [Indexed: 02/01/2023]
Abstract
In this paper, we describe the elucidation of the target of an aptamer against ovarian cancer previously obtained by cell-SELEX (SELEX = systematic evolution of ligands by exponential enrichment). The target's identity, stress-induced phosphoprotein 1 (STIP1), was determined by mass spectrometry and validated by flow cytometry, using siRNA silencing and protein blotting. Initial oncologic studies show that the aptamer inhibits cell invasion, indicating that STIP1, which is currently under investigation as a potential biomarker for ovarian cancer, plays a critical role in this process. These results serve as an excellent example of how protein target identification of aptamers obtained by cell-SELEX can serve as a means to identify promising biomarker candidates and can promote the development of aptamers as a new drug class to block important oncological processes.
Collapse
Affiliation(s)
- Dimitri Van Simaeys
- Center
for Research at Bio/Nano Interface, Departments of Chemistry and of
Physiology and Functional Genomics, Shands Cancer Center, UF Genetics
Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Diane Turek
- Center
for Research at Bio/Nano Interface, Departments of Chemistry and of
Physiology and Functional Genomics, Shands Cancer Center, UF Genetics
Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Carole Champanhac
- Center
for Research at Bio/Nano Interface, Departments of Chemistry and of
Physiology and Functional Genomics, Shands Cancer Center, UF Genetics
Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Julia Vaizer
- Center
for Research at Bio/Nano Interface, Departments of Chemistry and of
Physiology and Functional Genomics, Shands Cancer Center, UF Genetics
Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Kwame Sefah
- Center
for Research at Bio/Nano Interface, Departments of Chemistry and of
Physiology and Functional Genomics, Shands Cancer Center, UF Genetics
Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
| | - Jing Zhen
- Center
for Research at Bio/Nano Interface, Departments of Chemistry and of
Physiology and Functional Genomics, Shands Cancer Center, UF Genetics
Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
- Molecular
Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing
and Chemometrics, Colleges of Chemistry and Chemical Engineering and
of Biology, Collaborative Innovation Center for Molecular Engineering
and Theranostics, Hunan University, Changsha 410082, China
| | - Rebecca Sutphen
- Morsani
School of Medicine, University of South
Florida, Tampa, Florida 33612, United
States
| | - Weihong Tan
- Center
for Research at Bio/Nano Interface, Departments of Chemistry and of
Physiology and Functional Genomics, Shands Cancer Center, UF Genetics
Institute and McKnight Brain Institute, University of Florida, Gainesville, Florida 32611-7200, United States
- Molecular
Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Bio-Sensing
and Chemometrics, Colleges of Chemistry and Chemical Engineering and
of Biology, Collaborative Innovation Center for Molecular Engineering
and Theranostics, Hunan University, Changsha 410082, China
| |
Collapse
|
42
|
Shrivastav N, Fedeles BI, Li D, Delaney JC, Frick LE, Foti JJ, Walker GC, Essigmann JM. A chemical genetics analysis of the roles of bypass polymerase DinB and DNA repair protein AlkB in processing N2-alkylguanine lesions in vivo. PLoS One 2014; 9:e94716. [PMID: 24733044 PMCID: PMC3986394 DOI: 10.1371/journal.pone.0094716] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 03/18/2014] [Indexed: 01/06/2023] Open
Abstract
DinB, the E. coli translesion synthesis polymerase, has been shown to bypass several N2-alkylguanine adducts in vitro, including N2-furfurylguanine, the structural analog of the DNA adduct formed by the antibacterial agent nitrofurazone. Recently, it was demonstrated that the Fe(II)- and α-ketoglutarate-dependent dioxygenase AlkB, a DNA repair enzyme, can dealkylate in vitro a series of N2-alkyguanines, including N2-furfurylguanine. The present study explored, head to head, the in vivo relative contributions of these two DNA maintenance pathways (replicative bypass vs. repair) as they processed a series of structurally varied, biologically relevant N2-alkylguanine lesions: N2-furfurylguanine (FF), 2-tetrahydrofuran-2-yl-methylguanine (HF), 2-methylguanine, and 2-ethylguanine. Each lesion was chemically synthesized and incorporated site-specifically into an M13 bacteriophage genome, which was then replicated in E. coli cells deficient or proficient for DinB and AlkB (4 strains in total). Biochemical tools were employed to analyze the relative replication efficiencies of the phage (a measure of the bypass efficiency of each lesion) and the base composition at the lesion site after replication (a measure of the mutagenesis profile of each lesion). The main findings were: 1) Among the lesions studied, the bulky FF and HF lesions proved to be strong replication blocks when introduced site-specifically on a single-stranded vector in DinB deficient cells. This toxic effect disappeared in the strains expressing physiological levels of DinB. 2) AlkB is known to repair N2-alkylguanine lesions in vitro; however, the presence of AlkB showed no relief from the replication blocks induced by FF and HF in vivo. 3) The mutagenic properties of the entire series of N2-alkyguanines adducts were investigated in vivo for the first time. None of the adducts were mutagenic under the conditions evaluated, regardless of the DinB or AlkB cellular status. Taken together, the data indicated that the cellular pathway to combat bulky N2-alkylguanine DNA adducts was DinB-dependent lesion bypass.
Collapse
Affiliation(s)
- Nidhi Shrivastav
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Bogdan I. Fedeles
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Deyu Li
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - James C. Delaney
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Lauren E. Frick
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - James J. Foti
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Graham C. Walker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - John M. Essigmann
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Center for Environmental Health Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
43
|
Price N, Johnson KM, Wang J, Fekry MI, Wang Y, Gates KS. Interstrand DNA-DNA cross-link formation between adenine residues and abasic sites in duplex DNA. J Am Chem Soc 2014; 136:3483-90. [PMID: 24506784 PMCID: PMC3954461 DOI: 10.1021/ja410969x] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2013] [Indexed: 01/28/2023]
Abstract
The loss of a coding nucleobase from the structure of DNA is a common event that generates an abasic (Ap) site (1). Ap sites exist as an equilibrating mixture of a cyclic hemiacetal and a ring-opened aldehyde. Aldehydes are electrophilic functional groups that can form covalent adducts with nucleophilic sites in DNA. Thus, Ap sites present a potentially reactive aldehyde as part of the internal structure of DNA. Here we report evidence that the aldehyde group of Ap sites in duplex DNA can form a covalent adduct with the N(6)-amino group of adenine residues on the opposing strand. The resulting interstrand DNA-DNA cross-link occurs at 5'-ApT/5'-AA sequences in remarkably high yields (15-70%) under physiologically relevant conditions. This naturally occurring DNA-templated reaction has the potential to generate cross-links in the genetic material of living cells.
Collapse
Affiliation(s)
- Nathan
E. Price
- Department of Chemistry and Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Kevin M. Johnson
- Department of Chemistry and Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Jin Wang
- Department
of Chemistry, University of California-Riverside, Riverside, California 92521-0403, United States
| | - Mostafa I. Fekry
- Department of Chemistry and Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| | - Yinsheng Wang
- Department
of Chemistry, University of California-Riverside, Riverside, California 92521-0403, United States
| | - Kent S. Gates
- Department of Chemistry and Department of Biochemistry, University of Missouri, Columbia, Missouri 65211, United States
| |
Collapse
|
44
|
Tissue fixation and the effect of molecular fixatives on downstream staining procedures. Methods 2014; 70:12-9. [PMID: 24561827 PMCID: PMC4240801 DOI: 10.1016/j.ymeth.2014.01.022] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 01/30/2014] [Accepted: 01/31/2014] [Indexed: 01/11/2023] Open
Abstract
It is impossible to underplay the importance of fixation in histopathology. Whether the scientist is interested in the extraction of information on lipids, proteins, RNA or DNA, fixation is critical to this extraction. This review aims to give a brief overview of the current “state of play” in fixation and focus on the effect fixation, and particularly the effect of the newer brand of “molecular fixatives” have on morphology, histochemistry, immunohistochemistry and RNA/DNA analysis. A methodology incorporating the creation of a fixation tissue microarray for the study of the effect of fixation on histochemistry is detailed.
Collapse
|
45
|
Fluctuations in the DNA double helix: A critical review. Phys Life Rev 2014; 11:153-70. [PMID: 24560595 DOI: 10.1016/j.plrev.2014.01.005] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/27/2013] [Accepted: 12/30/2013] [Indexed: 12/22/2022]
Abstract
A critical overview of the extensive literature on fluctuations in the DNA double helix is presented. Both theory and experiment are comprehensively reviewed and analyzed. Fluctuations, which open up the DNA double helix making bases accessible for hydrogen exchange and chemical modification, are the main focus of the review. Theoretical descriptions of the DNA fluctuations are discussed with special emphasis on most popular among them: the nonlinear-dynamic Peyrard-Bishop-Dauxois (PBD) model and the empirical two-state (or helix-coil) model. The experimental data on the issue are comprehensibly overviewed in the historical retrospective with main emphasis on the hydrogen exchange data and formaldehyde kinetics. The theoretical descriptions are critically evaluated from the viewpoint of their applicability to describe DNA in water environment and from the viewpoint of agreement of their predictions with the reliable experimental data. The presented analysis makes it possible to conclude that, while the two-state model is most adequate from theoretical viewpoint and its predictions, based on an empirical parametrization, agree with experimental data very well, the PBD model is inapplicable to DNA in water from theoretical viewpoint on one hand and it makes predictions totally incompatible with reliable experimental data on the other. In particular, it is argued that any oscillation movements of nucleotides, assumed by the PBD model, are severely damped in water, that no "bubbles", which the PBD model predicts, exist in reality in linear DNA well below the melting range and the lifetime of an open state in DNA is actually 5 orders of magnitude longer than the value predicted by the PBD model.
Collapse
|
46
|
Li G, Glusac KD. Light-triggered proton and electron transfer in flavin cofactors. J Phys Chem A 2013; 112:4573-83. [PMID: 18433109 DOI: 10.1021/jp7117218] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The pH dependent behavior of two flavin cofactors, flavin-adenine dinucleotide (FAD) and flavin mononucleotide (FMN), has been characterized using femtosecond transient absorption spectroscopy for the first time. The flavin excited state was characterized in three states of protonation (Fl(-), Fl, and FlH(+)). We found that Fl and Fl(-) exhibit the same excited state absorption but that the lifetime of Fl(-) is much shorter than that of Fl. The transient absorption spectrum of FlH(+) is significantly different from Fl and Fl(-), suggesting that the electronic properties of the flavin chromophore become appreciably modified by protonation. We further studied the excited state protonation of the flavin and found that the protonation sites of the flavin in the ground and excited state are not equivalent. In the case of FAD, its excited state dynamics are controlled by the two conformations it adopts. At low and high pH, FAD adopts an "open" conformation and behaves the same as FMN. In a neutral pH range, FAD undergoes a fast excited state deactivation due to the "stacked" conformer. The transition from stacked to open conformer occurs at pH ~ 3 (because of adenine protonation) and pH ~ 10 (because of flavin deprotonation).
Collapse
Affiliation(s)
- Guifeng Li
- Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio 43403, USA
| | | |
Collapse
|
47
|
Troiano NW, Ciovacco WA, Kacena MA. The Effects of Fixation and Dehydration on the Histological Quality of Undecalcified Murine Bone Specimens Embedded in Methylmethacrylate. J Histotechnol 2013; 32:27-31. [PMID: 20160920 DOI: 10.1179/his.2009.32.1.27] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Histological evaluation is a complex, multistep process culminating in tissue staining. All of the steps leading up to the staining affect the final quality, but too often the effects of these preparations are not given enough consideration. Fixatives in particular usually are chosen not for efficacy but for convenience and availability. This study attempts to create guidelines for selecting fixatives for bone tissue histological evaluation. We compared two of the most widely used fixatives, ethanol and formalin, in their use on mouse tibias embedded in methylmethacrylate and subsequently stained with toluidine blue, safranin O, or Von Kossa. Our results show that ethanol fixation (70%) and subsequent processing in methylmethacrylate gives better staining results for bone cell related elements than fixing in 10% neutral buffered formalin with the same processing and embedding techniques. Further we demonstrated than an additional acetone dehydration and clearing step allowed for even better visualization in bone specimens fixed with 70% ethanol. However, the additional acetone step did not enhance visualization in bone specimens fixed with 10% neutral buffered formalin. Finally, marrow elements were more easily visualized when fixed with formalin as opposed to ethanol.
Collapse
Affiliation(s)
- Nancy W Troiano
- Department of Orthopaedics and Rehabilitation, Yale University School of Medicine, New Haven, CT
| | | | | |
Collapse
|
48
|
Eltoum I, Fredenburgh J, Myers RB, Grizzle WE. Introduction to the Theory and Practice of Fixation of Tissues. J Histotechnol 2013. [DOI: 10.1179/his.2001.24.3.173] [Citation(s) in RCA: 114] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
49
|
Eltoum I, Fredenburgh J, Grizzle WE. Advanced Concepts in Fixation: 1. Effects of Fixation on Immunohistochemistry, Reversibility of Fixation and Recovery of Proteins, Nucleic Acids, and other Molecules from Fixed and Processed Tissues. 2. Developmental Methods of Fixation. J Histotechnol 2013. [DOI: 10.1179/his.2001.24.3.201] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
50
|
Johnson KM, Price NE, Wang J, Fekry MI, Dutta S, Seiner DR, Wang Y, Gates KS. On the formation and properties of interstrand DNA-DNA cross-links forged by reaction of an abasic site with the opposing guanine residue of 5'-CAp sequences in duplex DNA. J Am Chem Soc 2013; 135:1015-25. [PMID: 23215239 DOI: 10.1021/ja308119q] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We recently reported that the aldehyde residue of an abasic (Ap) site in duplex DNA can generate an interstrand cross-link via reaction with a guanine residue on the opposing strand. This finding is intriguing because the highly deleterious nature of interstrand cross-links suggests that even small amounts of Ap-derived cross-links could make a significant contribution to the biological consequences stemming from the generation of Ap sites in cellular DNA. Incubation of 21-bp duplexes containing a central 5'-CAp sequence under conditions of reductive amination (NaCNBH(3), pH 5.2) generated much higher yields of cross-linked DNA than reported previously. At pH 7, in the absence of reducing agents, these Ap-containing duplexes also produced cross-linked duplexes that were readily detected on denaturing polyacrylamide gels. Cross-link formation was not highly sensitive to reaction conditions, and the cross-link, once formed, was stable to a variety of workup conditions. Results of multiple experiments including MALDI-TOF mass spectrometry, gel mobility, methoxyamine capping of the Ap aldehyde, inosine-for-guanine replacement, hydroxyl radical footprinting, and LC-MS/MS were consistent with a cross-linking mechanism involving reversible reaction of the Ap aldehyde residue with the N(2)-amino group of the opposing guanine residue in 5'-CAp sequences to generate hemiaminal, imine, or cyclic hemiaminal cross-links (7-10) that were irreversibly converted under conditions of reductive amination (NaCNBH(3)/pH 5.2) to a stable amine linkage. Further support for the importance of the exocyclic N(2)-amino group in this reaction was provided by an experiment showing that installation of a 2-aminopurine-thymine base pair at the cross-linking site produced high yields (15-30%) of a cross-linked duplex at neutral pH, in the absence of NaCNBH(3).
Collapse
Affiliation(s)
- Kevin M Johnson
- Department of Chemistry, University of Missouri, 125 Chemistry Building, Columbia, Missouri 65211, USA
| | | | | | | | | | | | | | | |
Collapse
|