1
|
Li X, Zeng H, Zhang L, Zhang J, Guo Y, Leng J. An integrated LC-MS/MS platform for noninvasive urinary nucleus acid adductomics: A pilot study for tobacco exposure. JOURNAL OF HAZARDOUS MATERIALS 2024; 474:134780. [PMID: 38861899 DOI: 10.1016/j.jhazmat.2024.134780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/22/2024] [Accepted: 05/29/2024] [Indexed: 06/13/2024]
Abstract
Tobacco smoke exposure significantly increases the level of global nucleoside damage. To evaluate all aspects of nucleic acid (NA) modifications, NA adductomics analyzes DNA, RNA and nucleobase adducts and provides comprehensive data. Liquid chromatography-tandem triple quadrupole mass spectrometry (LC-QQQ-MS/MS) and LC-Zeno-TOF-MS/MS were employed to screen for DNA, RNA and nucleobase adducts, as part of the analytical platform that was designed to combine high sensitivity and high resolution detection. We identified and distinguished urine nucleoside adducts via precursor ion and neutral loss scanning. A total of 245 potential adducts were detected, of which 28 were known adducts. The smoking group had significantly higher concentrations of nucleoside adducts in rat urine than the control group, based on MRM scanning, which was then used to perform relative quantitative analysis of these adducts. Urine nucleoside adducts were further confirmed using LC-Zeno-TOF-MS/MS. This highlights the potential of untargeted detection methods to provide comprehensive data on both known and unknown adducts. These approaches can be used to investigate the interactions among oxidative and alkylation stresses, and epigenetic modifications caused by exposure to tobacco smoke.
Collapse
Affiliation(s)
- Xiaoqing Li
- Comprehensive Exposure Research Center, School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
| | - Hui Zeng
- Comprehensive Exposure Research Center, School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China
| | - Li Zhang
- National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, PR China
| | - Jing Zhang
- National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, PR China
| | - Yinlong Guo
- National Center for Organic Mass Spectrometry in Shanghai, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, PR China.
| | - Jiapeng Leng
- Comprehensive Exposure Research Center, School of Pharmacy, Liaoning University of Traditional Chinese Medicine, Dalian 116600, China.
| |
Collapse
|
2
|
Li J, Hu Z, Liu D, Wang P. Mass spectrometry-based assays for assessing replicative bypass and repair of DNA alkylation in cells. RSC Adv 2023; 13:15490-15497. [PMID: 37223415 PMCID: PMC10201546 DOI: 10.1039/d2ra08340j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 05/15/2023] [Indexed: 05/25/2023] Open
Abstract
Endogenous metabolism and environmental exposure can give rise to DNA alkylation, which can elicit deleterious biological consequences. In the search for reliable and quantitative analytical methods to elucidate the impact of DNA alkylation on the flow of genetic information, mass spectrometry (MS) has attracted increasing attention, owing to its unambiguous determination of molecular mass. The MS-based assays obviate conventional colony-picking methods and Sanger sequencing procedures, and retained the high sensitivity of postlabeling methods. With the help of the CRISPR/Cas9 gene editing method, MS-based assays showed high potential in studying individual functions of repair proteins and translesion synthesis (TLS) polymerases in DNA replication. In this mini-review, we have summarized the development of MS-based competitive and replicative adduct bypass (CRAB) assays and their recent applications in assessing the impact of alkylation on DNA replication. With further development of MS instruments for high resolving power and high throughput, these assays should be generally applicable and efficient in quantitative measurement of the biological consequences and repair of other DNA lesions.
Collapse
Affiliation(s)
- Jiaxian Li
- Institute of Surface Analysis and Chemical Biology, University of Jinan Jinan Shandong 250022 P. R. China
| | - Zhihai Hu
- Institute of Surface Analysis and Chemical Biology, University of Jinan Jinan Shandong 250022 P. R. China
| | - Dandan Liu
- Institute of Surface Analysis and Chemical Biology, University of Jinan Jinan Shandong 250022 P. R. China
| | - Pengcheng Wang
- Institute of Surface Analysis and Chemical Biology, University of Jinan Jinan Shandong 250022 P. R. China
| |
Collapse
|
3
|
Liang H, He X, Tong Y, Bai N, Pu Y, Han K, Wang Y. Ferroptosis open a new door for colorectal cancer treatment. Front Oncol 2023; 13:1059520. [PMID: 37007121 PMCID: PMC10061081 DOI: 10.3389/fonc.2023.1059520] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Accepted: 02/21/2023] [Indexed: 03/18/2023] Open
Abstract
Colorectal cancer (CRC) is the third highest incidence and the second highest mortality malignant tumor in the world. The etiology and pathogenesis of CRC are complex. Due to the long course of the disease and no obvious early symptoms, most patients are diagnosed as middle and late stages. CRC is prone to metastasis, most commonly liver metastasis, which is one of the leading causes of death in CRC patients. Ferroptosis is a newly discovered cell death form with iron dependence, which is driven by excessive lipid peroxides on the cell membrane. It is different from other form of programmed cell death in morphology and mechanism, such as apoptosis, pyroptosis and necroptosis. Numerous studies have shown that ferroptosis may play an important role in the development of CRC. For advanced or metastatic CRC, ferroptosis promises to open a new door in the setting of poor response to chemotherapy and targeted therapy. This mini review focuses on the pathogenesis of CRC, the mechanism of ferroptosis and the research status of ferroptosis in CRC treatment. The potential association between ferroptosis and CRC and some challenges are discussed.
Collapse
Affiliation(s)
- Hong Liang
- Department of Pharmacy, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Xia He
- Department of Pharmacy, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
| | - Yitong Tong
- Chengdu Second People’s Hospital Party Committee Office, Chengdu, China
| | - Niuniu Bai
- Department of Pharmacy, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- School of Pharmacy, Shanxi Medical University, Taiyuan, China
| | - Yushu Pu
- Nanchang University Queen Mary School, Nanchang, China
| | - Ke Han
- Department of Pharmacy, Sichuan Academy of Medical Sciences & Sichuan Provincial People’s Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
- Department of Pharmacy, The First People’s Hospital of Chengdu, Chengdu, China
| | - Yi Wang
- Department of Critical Care Medicine, Sichuan Academy of Medical Science and Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sicuhan, China
| |
Collapse
|
4
|
Zhao Y, Zhao W, Li J, Lin S, Li L, Ren Z, Lu J, Xing X, Liu X. Effect of dietary consumption on the survival of esophageal squamous cell carcinoma: a prospective cohort study. Eur J Clin Nutr 2023; 77:55-64. [PMID: 35974139 DOI: 10.1038/s41430-022-01194-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 01/28/2023]
Abstract
BACKGROUND/OBJECTIVES This prospective cohort study was to assess the association of pre-diagnostic dietary intake and dietary pattern with the survival of esophageal squamous cell carcinoma (ESCC) patients. SUBJECTS/METHODS 855 patients were recruited and successfully followed. Information on diet over past five years before diagnosis was collected using a food frequency questionnaire, and dietary patterns were extracted using principal component analysis. Hazard ratio (HR) with 95% confidence interval (95% CI) was calculated using the Cox proportional hazard model. RESULTS 164 (19.18%) ESCC patients survived during the follow-up. Every 25-g increment intake of pickled vegetables was associated with a 6.0% (HR: 1.060, 95% CI: 1.003-1.121) increased risk of death after adjustment for covariates. When comparing the highest with lowest tertiles of energy-adjusted intake, pickled vegetables intake was associated with a 21.9% elevated risk of death (HR: 1.219, 95% CI: 1.014-1.465), while fish and shrimp intake was associated with a 19.4% (HR: 0.816, 95% CI: 0.675-0.986) reduced risk of death. Three dietary patterns were defined and labeled as patterns I, II, and III. Every 10-score increment of dietary pattern II, characterized with a higher loading of preserved vegetables, pickled vegetables, and salted meat, was associated with a 1.7% (HR: 1.017, 95% CI: 1.003-1.032) increased risk of death. CONCLUSIONS A diet characterized with higher loading of preserved vegetables, pickled vegetables, and salted meat, was negatively associated with death risk among ESCC patients. Prospective studies concerning the role of post-diagnosis dietary intake in ESCC prognosis are needed.
Collapse
Affiliation(s)
- Yue Zhao
- Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Wenjing Zhao
- School of Public Health and Emergency Management, Southern University of Science and Technology, Shenzhen, China
| | - Jun Li
- Department of Cancer Prevention and Treatment, Yanting Cancer Hospital, Mianyang, China
| | - Sihao Lin
- School of Management, Putian University, Putian, China
| | - Lin Li
- Department of Cancer Prevention and Treatment, Yanting Cancer Hospital, Mianyang, China
| | - Zefang Ren
- Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Jiahai Lu
- Department of Epidemiology, School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Xiangbing Xing
- Department of Gastroenterology, the First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xudong Liu
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China.
| |
Collapse
|
5
|
Cheng S, Che L, Yang Q, Sun R, Nie Y, Shi H, Ding Y, Wang L, Du Z, Liu Z. Folic acid ameliorates N-methyl-N′-nitro-N-nitrosoguanidine-induced esophageal inflammation via modulation of the NF-κB pathway. Toxicol Appl Pharmacol 2022; 447:116087. [DOI: 10.1016/j.taap.2022.116087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/20/2022] [Accepted: 05/21/2022] [Indexed: 12/24/2022]
|
6
|
Li X, Cao G, Liu X, Tang TS, Guo C, Liu H. Polymerases and DNA Repair in Neurons: Implications in Neuronal Survival and Neurodegenerative Diseases. Front Cell Neurosci 2022; 16:852002. [PMID: 35846567 PMCID: PMC9279898 DOI: 10.3389/fncel.2022.852002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 05/23/2022] [Indexed: 12/22/2022] Open
Abstract
Most of the neurodegenerative diseases and aging are associated with reactive oxygen species (ROS) or other intracellular damaging agents that challenge the genome integrity of the neurons. As most of the mature neurons stay in G0/G1 phase, replication-uncoupled DNA repair pathways including BER, NER, SSBR, and NHEJ, are pivotal, efficient, and economic mechanisms to maintain genomic stability without reactivating cell cycle. In these progresses, polymerases are prominent, not only because they are responsible for both sensing and repairing damages, but also for their more diversified roles depending on the cell cycle phase and damage types. In this review, we summarized recent knowledge on the structural and biochemical properties of distinct polymerases, including DNA and RNA polymerases, which are known to be expressed and active in nervous system; the biological relevance of these polymerases and their interactors with neuronal degeneration would be most graphically illustrated by the neurological abnormalities observed in patients with hereditary diseases associated with defects in DNA repair; furthermore, the vicious cycle of the trinucleotide repeat (TNR) and impaired DNA repair pathway is also discussed. Unraveling the mechanisms and contextual basis of the role of the polymerases in DNA damage response and repair will promote our understanding about how long-lived postmitotic cells cope with DNA lesions, and why disrupted DNA repair contributes to disease origin, despite the diversity of mutations in genes. This knowledge may lead to new insight into the development of targeted intervention for neurodegenerative diseases.
Collapse
Affiliation(s)
- Xiaoling Li
- Nano-Biotechnology Key Lab of Hebei Province, Yanshan University, Qinhuangdao, China
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
- Xiaoling Li
| | - Guanghui Cao
- Nano-Biotechnology Key Lab of Hebei Province, Yanshan University, Qinhuangdao, China
| | - Xiaokang Liu
- Nano-Biotechnology Key Lab of Hebei Province, Yanshan University, Qinhuangdao, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
| | - Caixia Guo
- Beijing Institute of Genomics, University of Chinese Academy of Sciences, Chinese Academy of Sciences/China National Center for Bioinformation, Beijing, China
- *Correspondence: Caixia Guo
| | - Hongmei Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, China
- Hongmei Liu
| |
Collapse
|
7
|
Li Y, Hecht SS. Metabolism and DNA Adduct Formation of Tobacco-Specific N-Nitrosamines. Int J Mol Sci 2022; 23:5109. [PMID: 35563500 PMCID: PMC9104174 DOI: 10.3390/ijms23095109] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/29/2022] [Accepted: 04/30/2022] [Indexed: 01/06/2023] Open
Abstract
The tobacco-specific N-nitrosamines 4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) always occur together and exclusively in tobacco products or in environments contaminated by tobacco smoke. They have been classified as "carcinogenic to humans" by the International Agency for Research on Cancer. In 1998, we published a review of the biochemistry, biology and carcinogenicity of tobacco-specific nitrosamines. Over the past 20 years, considerable progress has been made in our understanding of the mechanisms of metabolism and DNA adduct formation by these two important carcinogens, along with progress on their carcinogenicity and mutagenicity. In this review, we aim to provide an update on the carcinogenicity and mechanisms of the metabolism and DNA interactions of NNK and NNN.
Collapse
Affiliation(s)
- Yupeng Li
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
| | - Stephen S. Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA;
| |
Collapse
|
8
|
Li Y, Hecht SS. Metabolic Activation and DNA Interactions of Carcinogenic N-Nitrosamines to Which Humans Are Commonly Exposed. Int J Mol Sci 2022; 23:ijms23094559. [PMID: 35562949 PMCID: PMC9105260 DOI: 10.3390/ijms23094559] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/15/2022] [Accepted: 04/18/2022] [Indexed: 02/04/2023] Open
Abstract
Carcinogenic N-nitrosamine contamination in certain drugs has recently caused great concern and the attention of regulatory agencies. These carcinogens-widely detectable in relatively low levels in food, water, cosmetics, and drugs-are well-established and powerful animal carcinogens. The electrophiles resulting from the cytochrome P450-mediated metabolism of N-nitrosamines can readily react with DNA and form covalent addition products (DNA adducts) that play a central role in carcinogenesis if not repaired. In this review, we aim to provide a comprehensive and updated review of progress on the metabolic activation and DNA interactions of 10 carcinogenic N-nitrosamines to which humans are commonly exposed. Certain DNA adducts such as O6-methylguanine with established miscoding properties play central roles in the cancer induction process, whereas others have been linked to the high incidence of certain types of cancers. We hope the data summarized here will help researchers gain a better understanding of the bioactivation and DNA interactions of these 10 carcinogenic N-nitrosamines and facilitate further research on their toxicologic and carcinogenic properties.
Collapse
Affiliation(s)
- Yupeng Li
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA;
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA
- Correspondence: ; Tel.: +1-612-624-8187
| | - Stephen S. Hecht
- Masonic Cancer Center, University of Minnesota, Minneapolis, MN 55455, USA;
| |
Collapse
|
9
|
Aloisi CMN, Sandell ES, Sturla SJ. A Chemical Link between Meat Consumption and Colorectal Cancer Development? Chem Res Toxicol 2021; 34:12-23. [PMID: 33417435 DOI: 10.1021/acs.chemrestox.0c00395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
O6-carboxymethylguanine (O6-CMG) is a mutagenic DNA adduct that forms at increased levels when people eat meat. It has been studied as a potential initiating event in colorectal carcinogenesis. It can arise from alkylation of guanine in DNA by electrophilic degradation products of N-nitroso compounds. There is significant data regarding biochemical and cellular process, including DNA repair and translesion DNA synthesis that control O6-CMG accumulation, persistence, and mutagenicity. Mutation spectra arising from the adduct closely resemble common mutations in colorectal cancer; however, gaps remain in understanding the biochemical processes that regulate how and where the damage persists in the genome. Addressing such questions relies on advances in chemistry such as synthesis approaches and bioanalytical methods. Results of research in this area help advance our understanding of the toxicological relevance of O6-CMG-modified DNA. Further attention should focus on understanding how a combination of genetic and environmental factors control its biological persistence and how this information can be used as a basis of biomoniotoring and prevention efforts to help mitigate colon cancer risk.
Collapse
Affiliation(s)
- Claudia M N Aloisi
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Emma S Sandell
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| | - Shana J Sturla
- Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland
| |
Collapse
|
10
|
Wu J, Yuan J, Price NE, Wang Y. Ada protein- and sequence context-dependent mutagenesis of alkyl phosphotriester lesions in Escherichia coli cells. J Biol Chem 2020; 295:8775-8783. [PMID: 32381504 DOI: 10.1074/jbc.ra120.013657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 05/01/2020] [Indexed: 11/06/2022] Open
Abstract
Alkyl phosphotriester (alkyl-PTE) lesions are frequently induced in DNA and are resistant to repair. Here, we synthesized and characterized methyl (Me)- and n-butyl (nBu)-PTEs in two diastereomeric configurations (S p and R p) at six different flanking dinucleotide sites, i.e. XT and TX (X = A, C, or G), and assessed how these lesions impact DNA replication in Escherichia coli cells. When single-stranded vectors contained an S p-Me-PTE in the sequence contexts of 5'-AT-3', 5'-CT-3', or 5'-GT-3', DNA replication was highly efficient and the replication products for all three sequence contexts contained 85-90% AT and 5-10% TG. Thus, the replication outcome was largely independent of the identity of the 5' nucleotide adjacent to an S p-Me-PTE. Furthermore, replication across these lesions was not dependent on the activities of DNA polymerases II, IV, or V; Ada, a protein involved in adaptive response and repair of S p-Me-PTE in E. coli, however, was essential for the generation of the mutagenic products. Additionally, the R p diastereomer of Me-PTEs at XT sites and both diastereomers of Me-PTEs at TX sites exhibited error-free replication bypass. Moreover, S p-nBu-PTEs at XT sites did not strongly impede DNA replication, and other nBu-PTEs displayed moderate blockage effects, with none of them being mutagenic. Taken together, these findings provide in-depth understanding of how alkyl-PTE lesions are recognized by the DNA replication machinery in prokaryotic cells and reveal that Ada contributes to mutagenesis of S p-Me-PTEs in E. coli.
Collapse
Affiliation(s)
- Jiabin Wu
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA
| | - Jun Yuan
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA
| | - Nathan E Price
- Department of Chemistry, University of California, Riverside, California, USA
| | - Yinsheng Wang
- Environmental Toxicology Graduate Program, University of California, Riverside, California, USA; Department of Chemistry, University of California, Riverside, California, USA.
| |
Collapse
|
11
|
Biological Evaluation of DNA Biomarkers in a Chemically Defined and Site-Specific Manner. TOXICS 2019; 7:toxics7020036. [PMID: 31242562 PMCID: PMC6631660 DOI: 10.3390/toxics7020036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 06/13/2019] [Accepted: 06/14/2019] [Indexed: 02/06/2023]
Abstract
As described elsewhere in this Special Issue on biomarkers, much progress has been made in the detection of modified DNA within organisms at endogenous and exogenous levels of exposure to chemical species, including putative carcinogens and chemotherapeutic agents. Advances in the detection of damaged or unnatural bases have been able to provide correlations to support or refute hypotheses between the level of exposure to oxidative, alkylative, and other stresses, and the resulting DNA damage (lesion formation). However, such stresses can form a plethora of modified nucleobases, and it is therefore difficult to determine the individual contribution of a particular modification to alter a cell's genetic fate, as measured in the form of toxicity by stalled replication past the damage, by subsequent mutation, and by lesion repair. Chemical incorporation of a modification at a specific site within a vector (site-specific mutagenesis) has been a useful tool to deconvolute what types of damage quantified in biologically relevant systems may lead to toxicity and/or mutagenicity, thereby allowing researchers to focus on the most relevant biomarkers that may impact human health. Here, we will review a sampling of the DNA modifications that have been studied by shuttle vector techniques.
Collapse
|