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World Journal of Microbiology &... Apr 2024DNA adduction in the model yeast Saccharomyces cerevisiae was investigated after exposure to the fungicide penconazole and the reference genotoxic compound...
DNA adduction in the model yeast Saccharomyces cerevisiae was investigated after exposure to the fungicide penconazole and the reference genotoxic compound benzo(a)pyrene, for validating yeasts as a tool for molecular toxicity studies, particularly of environmental pollution. The effect of the toxicants on the yeast's growth kinetics was determined as an indicator of cytotoxicity. Fermentative cultures of S. cerevisiae were exposed to 2 ppm of Penconazole during different phases of growth; while 0.2 and 2 ppm of benzo(a)pyrene were applied to the culture medium before inoculation and on exponential cultures. Exponential respiratory cultures were also exposed to 0.2 ppm of B(a)P for comparison of both metabolisms. Penconazole induced DNA adducts formation in the exponential phase test; DNA adducts showed a peak of 54.93 adducts/10 nucleotides. Benzo(a)pyrene induced the formation of DNA adducts in all the tests carried out; the highest amount of 46.7 adducts/10 nucleotides was obtained in the fermentative cultures after the exponential phase exposure to 0.2 ppm; whereas in the respiratory cultures, 14.6 adducts/10 nucleotides were detected. No cytotoxicity was obtained in any experiment. Our study showed that yeast could be used to analyse DNA adducts as biomarkers of exposure to environmental toxicants.
Topics: DNA Adducts; Saccharomyces cerevisiae; Benzo(a)pyrene; Environmental Pollutants; Mutagens; DNA, Fungal; Fungicides, Industrial
PubMed: 38668960
DOI: 10.1007/s11274-024-03989-x -
Journal of Cancer Research and Clinical... Apr 2024Morinda citrifolia fruit juice (noni) is an herbal remedy documented to have antioxidant properties. It has been suggested that prevention of carcinogen-DNA adduct...
BACKGROUND AND AIM
Morinda citrifolia fruit juice (noni) is an herbal remedy documented to have antioxidant properties. It has been suggested that prevention of carcinogen-DNA adduct formation and the antioxidant activity of NJ may contribute to the cancer preventive effect. In the present study, the antitumor activity of noni was investigated in the presence of cyclophosphamide (CYL) in vitro and in vivo.
METHODS
In vitro breast cancer cells (MDA-MB-468) were used to measure the percentage of inhibition and the IC. The in vivo antitumor activity of noni was studied by monitoring the mean survival time (MST), percentage increase in life span (%ILS), viable and non-viable cell count, tumor volume, body weight, and hematological and serum biochemical parameters in mice. Treatment with noni and CYL exhibited dose- and time-dependent cytotoxicity toward breast cancer cells.
RESULTS
Individual treatment of noni and CYL exhibited dose- and time-dependent cytotoxicity on breast cancer cell lines, while in combination therapy of noni and CYL, noni enhances cytotoxic effect of CYL at 48 h than that at 24 h. Similar result was found in in vivo studies, the results of which revealed that alone treatment of CYL and noni suppressed tumor growth. However, combination treatment with CYL and noni presented better tumor inhibition than that of alone treatment of CYL and noni. On the contrary, CYL alone drastically attenuated hematological parameters, i.e., RBC, WBC, and Hb compared to normal and control groups, and this change was reversed and normalized by noni when given as combination therapy with CYL. Moreover, the levels of serum biochemical markers, i.e., AST, ALP, and ALT, were significantly increased in the control and CYL-treated groups than those in the normal group. In the combination treatment of noni and CYL, the above biochemical marker levels significantly decreased compared to CYL alone-treated group.
CONCLUSIONS
The present study suggested that CYL treatment can cause serious myelotoxicity and hepatic injury in cancer patients. In conclusion, the combined use of noni with CYL potentially enhances the antitumor activity of CYL and suppresses myelotoxicity and hepatotoxicity induced by CYL in tumor-bearing mice.
Topics: Animals; Cyclophosphamide; Mice; Humans; Female; Morinda; Breast Neoplasms; Cell Line, Tumor; Fruit and Vegetable Juices; Xenograft Model Antitumor Assays; Drug Synergism; Plant Extracts; Antineoplastic Combined Chemotherapy Protocols; Antineoplastic Agents, Alkylating; Mice, Inbred BALB C; Chemical and Drug Induced Liver Injury
PubMed: 38662247
DOI: 10.1007/s00432-024-05734-1 -
Archives of Toxicology Jul 2024Tobacco carcinogens metabolism-related genes (TCMGs) could generate reactive metabolites of tobacco carcinogens, which subsequently contributed to multiple diseases....
Tobacco carcinogens metabolism-related genes (TCMGs) could generate reactive metabolites of tobacco carcinogens, which subsequently contributed to multiple diseases. However, the association between genetic variants in TCMGs and bladder cancer susceptibility remains unclear. In this study, we derived TCMGs from metabolic pathways of polycyclic aromatic hydrocarbons and tobacco-specific nitrosamines, and then explored genetic associations between TCMGs and bladder cancer risk in two populations: a Chinese population of 580 cases and 1101 controls, and a European population of 5930 cases and 5468 controls, along with interaction and joint analyses. Expression patterns of TCMGs were sourced from Nanjing Bladder Cancer (NJBC) study and publicly available datasets. Among 43 TCMGs, we observed that rs7087341 T > A in AKR1C2 was associated with a reduced risk of bladder cancer in the Chinese population [odds ratio (OR) = 0.84, 95% confidence interval (CI) = 0.72-0.97, P = 1.86 × 10]. Notably, AKR1C2 rs7087341 showed an interaction effect with cigarette smoking on bladder cancer risk (P = 5.04 × 10), with smokers carrying the T allele increasing the risk up to an OR of 3.96 (P < 0.001). Genetically, rs7087341 showed an allele-specific transcriptional regulation as located at DNA-sensitive regions of AKR1C2 highlighted by histone markers. Mechanistically, rs7087341 A allele decreased AKR1C2 expression, which was highly expressed in bladder tumors that enhanced metabolism of tobacco carcinogens, and thereby increased DNA adducts and reactive oxygen species formation during bladder tumorigenesis. These findings provided new insights into the genetic mechanisms underlying bladder cancer.
Topics: Humans; Urinary Bladder Neoplasms; Genetic Predisposition to Disease; Carcinogens; Male; Female; Middle Aged; Case-Control Studies; Polymorphism, Single Nucleotide; Asian People; China; Nicotiana; Aged; White People; Cigarette Smoking; Nitrosamines; Hydroxysteroid Dehydrogenases
PubMed: 38662237
DOI: 10.1007/s00204-024-03737-y -
Nucleic Acids Research Jun 2024Mitomycin C (MMC) repair factor A (mrfA) and factor B (mrfB), encode a conserved helicase and exonuclease that repair DNA damage in the soil-dwelling bacterium Bacillus...
Mitomycin C (MMC) repair factor A (mrfA) and factor B (mrfB), encode a conserved helicase and exonuclease that repair DNA damage in the soil-dwelling bacterium Bacillus subtilis. Here we have focused on the characterization of MrfB, a DEDDh exonuclease in the DnaQ superfamily. We solved the structure of the exonuclease core of MrfB to a resolution of 2.1 Å, in what appears to be an inactive state. In this conformation, a predicted α-helix containing the catalytic DEDDh residue Asp172 adopts a random coil, which moves Asp172 away from the active site and results in the occupancy of only one of the two catalytic Mg2+ ions. We propose that MrfB resides in this inactive state until it interacts with DNA to become activated. By comparing our structure to an AlphaFold prediction as well as other DnaQ-family structures, we located residues hypothesized to be important for exonuclease function. Using exonuclease assays we show that MrfB is a Mg2+-dependent 3'-5' DNA exonuclease. We show that Leu113 aids in coordinating the 3' end of the DNA substrate, and that a basic loop is important for substrate binding. This work provides insight into the function of a recently discovered bacterial exonuclease important for the repair of MMC-induced DNA adducts.
Topics: Mitomycin; Magnesium; Bacillus subtilis; Bacterial Proteins; Models, Molecular; Catalytic Domain; DNA Repair; Exodeoxyribonucleases; Crystallography, X-Ray; DNA; Exonucleases
PubMed: 38661211
DOI: 10.1093/nar/gkae308 -
BioRxiv : the Preprint Server For... Apr 2024Treatment with genotoxic agents, such as platinum compounds, is still the mainstay therapeutical approach for the majority of cancers. Our understanding of the...
Treatment with genotoxic agents, such as platinum compounds, is still the mainstay therapeutical approach for the majority of cancers. Our understanding of the mechanisms of action of these drugs is however imperfect, and continuously evolving. Recent advances in the field highlighted single stranded DNA (ssDNA) gap accumulation as a potential determinant underlying cisplatin chemosensitivity, at least in some genetic backgrounds, such as BRCA mutations. Cisplatin-induced ssDNA gaps form upon the arrest of replication forks at sites of cisplatin adducts, and restart of DNA synthesis downstream of the lesion through repriming catalyzed by the PRIMPOL enzyme. Here, we show that PRIMPOL overexpression in otherwise wildtype cells results in accumulation of cisplatin-induced ssDNA gaps without sensitizing cells to cisplatin, suggesting that ssDNA gap accumulation does not confer cisplatin sensitivity in BRCA-proficient cells. To understand how ssDNA gaps may cause cellular sensitivity, we employed CRISPR-mediated genome-wide genetic screening to identify factors which enable the cytotoxicity of cisplatin-induced ssDNA gaps. We found that the helicase HELQ specifically suppresses cisplatin sensitivity in PRIMPOL-overexpressing cells, and this is associated with reduced ssDNA accumulation. We moreover identify RAD52 as a mediator of this pathway, and show that RAD52 promotes ssDNA gap accumulation through a BRCA-mediated mechanism. Our work identified the HELQ-RAD52-BRCA axis as a regulator of ssDNA gap processing, shedding light on the mechanisms of cisplatin sensitization in cancer therapy.
PubMed: 38659927
DOI: 10.1101/2024.04.17.589988 -
Research Square Apr 2024Malaria is a major public health problem, but many of the factors underlying the pathogenesis of this disease are not well understood. Here, we demonstrate in Malian...
Malaria is a major public health problem, but many of the factors underlying the pathogenesis of this disease are not well understood. Here, we demonstrate in Malian children that susceptibility to febrile malaria following infection with is associated with the composition of the gut microbiome prior to the malaria season. Gnotobiotic mice colonized with the fecal samples of malaria-susceptible children had a significantly higher parasite burden following infection compared to gnotobiotic mice colonized with the fecal samples of malaria-resistant children. The fecal microbiome of the susceptible children was enriched for bacteria associated with inflammation, mucin degradation, gut permeability and inflammatory bowel disorders (e.g., and sp. YL32). However, the susceptible children also had a greater abundance of bacteria known to produce anti-inflammatory short-chain fatty acids and those associated with favorable prognosis and remission following dysbiotic intestinal events (e.g., and . Metabolomics analysis of the human fecal samples corroborated the existence of inflammatory and recovery-associated features within the gut microbiome of the susceptible children. There was an enrichment of nitric oxide-derived DNA adducts (deoxyinosine and deoxyuridine) and long-chain fatty acids, the absorption of which has been shown to be inhibited by inflamed intestinal epithelial cells, and a decrease in the abundance of mucus phospholipids. Nevertheless, there were also increased levels of pseudouridine and hypoxanthine, which have been shown to be regulated in response to cellular stress and to promote recovery following injury or hypoxia. Overall, these results indicate that the gut microbiome may contribute malaria pathogenesis and suggest that therapies targeting intestinal inflammation could decrease malaria susceptibility.
PubMed: 38645126
DOI: 10.21203/rs.3.rs-3974068/v1 -
European Journal of Medicinal Chemistry May 2024In an initial screening, a series of novel Knoevenagel adducts were submitted to the National Cancer Institute for evaluation of antitumor activity in human cell lines....
In an initial screening, a series of novel Knoevenagel adducts were submitted to the National Cancer Institute for evaluation of antitumor activity in human cell lines. In particular, compound 5f showed remarkable selectivity against IGROV1, an ovarian cancer cell line, without affecting healthy human fibroblast cells. Analyses of cytotoxicity, cell proliferation, cell migration, epigenetic changes, gene expression, and DNA damage were performed to obtain detailed information about its antitumor properties. Our results show that 5f causes proliferation arrest, decrease in motility, histone hyperacetylation, downregulation of cyclin D1 and α5 subunit of integrin β1 gene transcription. In addition, 5f treatment reduces transcript and protein levels of cyclin D1, which increases sensitivity to ionizing radiation and results in DNA damage comparable to cyclin D1 gene silencing.
Topics: Humans; Cell Proliferation; Antineoplastic Agents; Structure-Activity Relationship; Drug Screening Assays, Antitumor; Molecular Structure; Dose-Response Relationship, Drug; Cell Line, Tumor; Cell Movement; Indoles; DNA Damage
PubMed: 38640869
DOI: 10.1016/j.ejmech.2024.116365 -
Environmental Toxicology and... Jun 2024The concept of the exposome is the encompassing of all the environmental exposures, both exogenous and endogenous, across the life course. Many, if not all, of these... (Review)
Review
The concept of the exposome is the encompassing of all the environmental exposures, both exogenous and endogenous, across the life course. Many, if not all, of these exposures can result in the generation of reactive species, and/or the modulation of cellular processes, that can lead to a breadth of modifications of DNA, the nature of which may be used to infer their origin. Because of their role in cell function, such modifications have been associated with various major human diseases, including cancer, and so their assessment is crucial. Historically, most methods have been able to only measure one or a few DNA modifications at a time, limiting the information available. With the development of DNA adductomics, which aims to determine the totality of DNA modifications, a far more comprehensive picture of the DNA adduct burden can be gained. Importantly, DNA adductomics can facilitate a "top-down" investigative approach whereby patterns of adducts may be used to trace and identify the originating exposure source. This, together with other 'omic approaches, represents a major tool for unraveling the complexities of the exposome and hence allow a better a understanding of the environmental origins of disease.
Topics: Humans; DNA Adducts; Exposome; Environmental Exposure; Biomarkers; Animals; DNA
PubMed: 38636743
DOI: 10.1016/j.etap.2024.104449 -
Forensic Science International May 2024Since its first employment in World War I, chlorine gas has often been used as chemical warfare agent. Unfortunately, after suspected release, it is difficult to prove...
Since its first employment in World War I, chlorine gas has often been used as chemical warfare agent. Unfortunately, after suspected release, it is difficult to prove the use of chlorine as a chemical weapon and unambiguous verification is still challenging. Furthermore, similar evidence can be found for exposure to chlorine gas and other, less harmful chlorinating agents. Therefore, the current study aims to use untargeted high resolution mass spectrometric analysis of chlorinated biomarkers together with machine learning techniques to be able to differentiate between exposure of plants to various chlorinating agents. Green spire (Euonymus japonicus), stinging nettle (Urtica dioica), and feathergrass (Stipa tenuifolia) were exposed to 1000 and 7500 ppm chlorine gas and household bleach, pool bleach, and concentrated sodium hypochlorite. After sample preparation and digestion, the samples were analyzed by liquid chromatography high resolution tandem mass spectrometry (LC-HRMS/MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS). More than 150 chlorinated compounds including plant fatty acids, proteins, and DNA adducts were tentatively identified. Principal component analysis (PCA) and linear discriminant analysis (LDA) showed clear discrimination between chlorine gas and bleach exposure and grouping of the samples according to chlorine concentration and type of bleach. The identity of a set of novel biomarkers was confirmed using commercially available or synthetic reference standards. Chlorodopamine, dichlorodopamine, and trichlorodopamine were identified as specific markers for chlorine gas exposure. Fenclonine (Cl-Phe), 3-chlorotyrosine (Cl-Tyr), 3,5-dichlorotyrosine (di-Cl-Tyr), and 5-chlorocytosine (Cl-Cyt) were more abundantly present in plants after chlorine contact. In contrast, the DNA adduct 2-amino-6-chloropurine (Cl-Ade) was identified in both types of samples at a similar level. None of these chlorinated biomarkers were observed in untreated samples. The DNA adducts Cl-Cyt and Cl-Ade could clearly be identified even three months after the actual exposure. This study demonstrates the feasibility of forensic biomarker profiling in plants to distinguish between exposure to chlorine gas and bleach.
Topics: Chlorine; Biomarkers; Principal Component Analysis; Chromatography, Liquid; Discriminant Analysis; Tandem Mass Spectrometry; Sodium Hypochlorite; DNA Adducts; Disinfectants; Chemical Warfare Agents; Fatty Acids; Plant Proteins
PubMed: 38615427
DOI: 10.1016/j.forsciint.2024.112022 -
Environmental Pollution (Barking, Essex... Jun 2024Urbanization has numerous benefits to human society, but some aspects of urban environments, such as air pollution, can negatively affect human health. Two major air... (Meta-Analysis)
Meta-Analysis Review
Urbanization has numerous benefits to human society, but some aspects of urban environments, such as air pollution, can negatively affect human health. Two major air pollutants, particulate matter (PM) and polycyclic aromatic hydrocarbons (PAH), have been classified as carcinogens by the International Agency for Research on Cancer. Here, we answer two questions: (1) What are the carcinogenic effects of PM and PAH exposure? (2) How does carcinogenic risk vary across geographical regions? We performed a comprehensive literature search of peer-reviewed published studies examining the link between air pollution and human cancer rates. Focusing on studies published since 2014 when the last IARC monograph on air pollution was published, we converted the extracted data into relative risks and performed subgroup analyses. Exposure to PM (per 10 μg/m) resulted in an 8.5% increase in cancer incidence when all cancer types were combined, and risk for individual cancer types (i.e. lung cancer and adenocarcinoma) was also elevated. PM was also associated with 2.5% higher mortality due to cancer when all types of cancer were combined, and for individual cancer types (i.e., lung and breast cancer). Exposure to PM and PM posed the greatest risk to lung cancer incidence and mortality in Europe (PM RR 2.15; PM RR 1.26); the risk in Asia and the Americas was also elevated. Exposure to PAH and benzo[a]pyrene significantly increased the pooled risk of cancer incidence (10.8% and 8.0% respectively) at the highest percentile of exposure concentration. Our meta-analyses of studies over the past decade shows that urban air pollution in the form of PM, PM, and PAH all elevate the incidence and mortality of cancer. We discuss the possible mechanisms of carcinogenesis of PM and PAH. These results support World Health Organization's conclusion that air pollution poses among the greatest health risks to humans living in cities.
Topics: Particulate Matter; Polycyclic Aromatic Hydrocarbons; Humans; Air Pollutants; Neoplasms; Environmental Exposure; Air Pollution; Carcinogens
PubMed: 38614427
DOI: 10.1016/j.envpol.2024.123941