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EXS 2009A genotoxin is a chemical or agent that can cause DNA or chromosomal damage. Such damage in a germ cell has the potential to cause a heritable altered trait (germline... (Review)
Review
A genotoxin is a chemical or agent that can cause DNA or chromosomal damage. Such damage in a germ cell has the potential to cause a heritable altered trait (germline mutation). DNA damage in a somatic cell may result in a somatic mutation, which may lead to malignant transformation (cancer). Many in vitro and in vivo tests for genotoxicity have been developed that, with a range of endpoints, detect DNA damage or its biological consequences in prokaryotic (e.g. bacterial) or eukaryotic (e.g. mammalian, avian or yeast) cells. These assays are used to evaluate the safety of environmental chemicals and consumer products and to explore the mechanism of action of known or suspected carcinogens. Many chemical carcinogens/mutagens undergo metabolic activation to reactive species that bind covalently to DNA, and the DNA adducts thus formed can be detected in cells and in human tissues by a variety of sensitive techniques. The detection and characterisation of DNA adducts in human tissues provides clues to the aetiology of human cancer. Characterisation of gene mutations in human tumours, in common with the known mutagenic profiles of genotoxins in experimental systems, may provide further insight into the role of environmental mutagens in human cancer.
Topics: Animals; Carcinogens; DNA Adducts; DNA Damage; Environmental Pollutants; Mutagenicity Tests; Mutagens; Toxicogenetics
PubMed: 19157059
DOI: 10.1007/978-3-7643-8336-7_4 -
Photochemistry and Photobiology 2015Sequencing complete tumor genomes and exomes has sparked the cancer field's interest in mutation signatures for identifying the tumor's carcinogen. This review and... (Review)
Review
Sequencing complete tumor genomes and exomes has sparked the cancer field's interest in mutation signatures for identifying the tumor's carcinogen. This review and meta-analysis discusses signatures and their proper use. We first distinguish between a mutagen's canonical mutations—deviations from a random distribution of base changes to create a pattern typical of that mutagen—and the subset of signature mutations, which are unique to that mutagen and permit inference backward from mutations to mutagen. To verify UV signature mutations, we assembled literature datasets on cells exposed to UVC, UVB, UVA, or solar simulator light (SSL) and tested canonical UV mutation features as criteria for clustering datasets. A confirmed UV signature was: ≥60% of mutations are C→T at a dipyrimidine site, with ≥5% CC→TT. Other canonical features such as a bias for mutations on the nontranscribed strand or at the 3' pyrimidine had limited application. The most robust classifier combined these features with criteria for the rarity of non-UV canonical mutations. In addition, several signatures proposed for specific UV wavelengths were limited to specific genes or species; UV's nonsignature mutations may cause melanoma BRAF mutations; and the mutagen for sunlight-related skin neoplasms may vary between continents.
Topics: Mutagens; Mutation; Ultraviolet Rays
PubMed: 25354245
DOI: 10.1111/php.12377 -
Chemical Research in Toxicology Jul 2023Aldehydes are widespread in the environment, with multiple sources such as food and beverages, industrial effluents, cigarette smoke, and additives. The toxic effects of... (Review)
Review
Aldehydes are widespread in the environment, with multiple sources such as food and beverages, industrial effluents, cigarette smoke, and additives. The toxic effects of exposure to several aldehydes have been observed in numerous studies. At the molecular level, aldehydes damage DNA, cross-link DNA and proteins, lead to lipid peroxidation, and are associated with increased disease risk including cancer. People genetically predisposed to aldehyde sensitivity exhibit severe health outcomes. In various diseases such as Fanconi's anemia and Cockayne syndrome, loss of aldehyde-metabolizing pathways in conjunction with defects in DNA repair leads to widespread DNA damage. Importantly, aldehyde-associated mutagenicity is being explored in a growing number of studies, which could offer key insights into how they potentially contribute to tumorigenesis. Here, we review the genotoxic effects of various aldehydes, focusing particularly on the DNA adducts underlying the mutagenicity of environmentally derived aldehydes. We summarize the chemical structures of the aldehydes and their predominant DNA adducts, discuss various methodologies, and , commonly used in measuring aldehyde-associated mutagenesis, and highlight some recent studies looking at aldehyde-associated mutation signatures and spectra. We conclude the Review with a discussion on the challenges and future perspectives of investigating aldehyde-associated mutagenesis.
Topics: Humans; Aldehydes; DNA Adducts; DNA Damage; DNA Repair; Mutagens; DNA
PubMed: 37363863
DOI: 10.1021/acs.chemrestox.3c00045 -
Marine Drugs May 2021The marine ecosystem, populated by a myriad of animals, plants, and microorganisms, is an inexhaustible reservoir of pharmacologically active molecules. Among the... (Review)
Review
The marine ecosystem, populated by a myriad of animals, plants, and microorganisms, is an inexhaustible reservoir of pharmacologically active molecules. Among the multiple secondary metabolites produced by marine sources, there are anthraquinones and their derivatives. Besides being mainly known to be produced by terrestrial species, even marine organisms and the uncountable kingdom of marine microorganisms biosynthesize anthraquinones. Anthraquinones possess many different biological activities, including a remarkable antitumor activity. However, due to their peculiar chemical structures, anthraquinones are often associated with toxicological issues, even relevant, such as genotoxicity and mutagenicity. The aim of this review is to critically describe the anticancer potential of anthraquinones derived from marine sources and their genotoxic and mutagenic potential. Marine-derived anthraquinones show a promising anticancer potential, although clinical studies are missing. Additionally, an in-depth investigation of their toxicological profile is needed before advocating anthraquinones as a therapeutic armamentarium in the oncological area.
Topics: Animals; Anthraquinones; Antineoplastic Agents; Aquatic Organisms; Cell Line, Tumor; Humans; Mutagens; Neoplasms
PubMed: 34068184
DOI: 10.3390/md19050272 -
Regulatory Toxicology and Pharmacology... Apr 2019Two studies were conducted to further assess its mutagenic and genotoxic potential. In a bacterial reverse mutation pre-incubation study, Salmonella typhimurium strains... (Review)
Review
Two studies were conducted to further assess its mutagenic and genotoxic potential. In a bacterial reverse mutation pre-incubation study, Salmonella typhimurium strains TA100, TA1535, TA98, and TA1537 and Escherichia coli WP2 uvrA were treated with aspartame at concentrations of up to 5000 μg/plate with or without metabolic activation and showed no mutagenic potential. Similarly, in vivo micronucleus testing of aspartame following gavage administration (500-2000 mg/kg body weight) to Crlj:CD1(ICR) strain SPF male mice showed no increase in the proportion of micronucleated polychromatic erythrocytes in bone marrow cells collected and evaluated 24 or 48 h post administration. Overall, aspartame had no potential for mutagenic or genotoxic activity.
Topics: Administration, Oral; Animals; Aspartame; Humans; Mice; Mice, Inbred ICR; Mutagenicity Tests; Mutagens; Sweetening Agents
PubMed: 29408486
DOI: 10.1016/j.yrtph.2018.01.023 -
IARC Monographs on the Evaluation of... 1999
Review
Topics: Animals; Carcinogenicity Tests; Humans; Mutagenicity Tests; Mutagens; Neoplasms; Neoplasms, Experimental; Occupational Exposure; Salmonella typhimurium; Xylenes
PubMed: 10476386
DOI: No ID Found -
IARC Monographs on the Evaluation of... 1999
Review
Topics: Animals; Carcinogenicity Tests; Carcinogens; Humans; Mutagenicity Tests; Mutagens; Neoplasms, Experimental; Propiolactone; Salmonella typhimurium
PubMed: 10476379
DOI: No ID Found -
Environmental Science and Pollution... Sep 2022
Topics: Animals; Environment; Humans; Mutagenesis; Mutagenicity Tests; Mutagens
PubMed: 35917065
DOI: 10.1007/s11356-022-22247-x -
Environmental Science and Pollution... Sep 2022The etiology of the majority of human cancers is associated with a myriad of environmental causes, including physical, chemical, and biological factors. DNA damage... (Review)
Review
The etiology of the majority of human cancers is associated with a myriad of environmental causes, including physical, chemical, and biological factors. DNA damage induced by such mutagens is the initial step in the process of carcinogenesis resulting in the accumulation of mutations. Mutational events are considered the major triggers for introducing genetic and epigenetic insults such as DNA crosslinks, single- and double-strand DNA breaks, formation of DNA adducts, mismatched bases, modification in histones, DNA methylation, and microRNA alterations. However, DNA repair mechanisms are devoted to protect the DNA to ensure genetic stability, any aberrations in these calibrated mechanisms provoke cancer occurrence. Comprehensive knowledge of the type of mutagens and carcinogens and the influence of these agents in DNA damage and cancer induction is crucial to develop rational anticancer strategies. This review delineated the molecular mechanism of DNA damage and the repair pathways to provide a deep understanding of the molecular basis of mutagenicity and carcinogenicity. A relationship between DNA adduct formation and cancer incidence has also been summarized. The mechanistic basis of inflammatory response and oxidative damage triggered by mutagens in tumorigenesis has also been highlighted. We elucidated the interesting interplay between DNA damage response and immune system mechanisms. We addressed the current understanding of DNA repair targeted therapies and DNA damaging chemotherapeutic agents for cancer treatment and discussed how antiviral agents, anti-inflammatory drugs, and immunotherapeutic agents combined with traditional approaches lay the foundations for future cancer therapies.
Topics: Carcinogens; DNA; DNA Damage; DNA Repair; Humans; Mutagens; Neoplasms
PubMed: 34611806
DOI: 10.1007/s11356-021-16726-w -
Journal of Applied Toxicology : JAT Apr 2010Pyrrolizidine alkaloids (PAs) are common constituents of many plant species around the world. PA-containing plants are probably the most common poisonous plants... (Review)
Review
Pyrrolizidine alkaloids (PAs) are common constituents of many plant species around the world. PA-containing plants are probably the most common poisonous plants affecting livestock and wildlife. They can inflict harm to humans through contaminated food sources, herbal medicines and dietary supplements. Half of the identified PAs are genotoxic and many of them are tumorigenic. The mutagenicity of PAs has been extensively studied in different biological systems. Upon metabolic activation, PAs produce DNA adducts, DNA cross-linking, DNA breaks, sister chromatid exchange, micronuclei, chromosomal aberrations, gene mutations and chromosome mutations in vivo and in vitro. PAs induced mutations in the cII gene of rat liver and in the p53 and K-ras genes of mouse liver tumors. It has been suggested that all PAs produce a set of (+/-)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine-derived DNA adducts and similar types of gene mutations. The signature types of mutations are G : C --> T : A transversion and tandem base substitutions. Overall, PAs are mutagenic in vivo and in vitro and their mutagenicity appears to be responsible for the carcinogenesis of PAs.
Topics: Animals; Carcinogens, Environmental; Chemical and Drug Induced Liver Injury; Chromosome Aberrations; DNA Damage; Humans; Mutagens; Mutation; Plants, Toxic; Pyrrolizidine Alkaloids
PubMed: 20112250
DOI: 10.1002/jat.1504