Environmental and Molecular Mutagenesis最新文献

{"title":"Mouse models to explore the biological and organismic role of DNA polymerase beta","authors":"Robert W. Sobol","doi":"10.1002/em.22593","DOIUrl":"https://doi.org/10.1002/em.22593","url":null,"abstract":"<p>Gene knock-out (KO) mouse models for DNA polymerase beta (Polβ) revealed that loss of Polβ leads to neonatal lethality, highlighting the critical organismic role for this DNA polymerase. While biochemical analysis and gene KO cell lines have confirmed its biochemical role in base excision repair and in TET-mediated demethylation, more long-lived mouse models continue to be developed to further define its organismic role. The <i>Polb</i>-KO mouse was the first of the Cre-mediated tissue-specific KO mouse models. This technology was exploited to investigate roles for Polβ in V(D)J recombination (variable-diversity-joining rearrangement), DNA demethylation, gene complementation, SPO11-induced DNA double-strand break repair, germ cell genome stability, as well as neuronal differentiation, susceptibility to genotoxin-induced DNA damage, and cancer onset. The revolution in knock-in (KI) mouse models was made possible by CRISPR/cas9-mediated gene editing directly in C57BL/6 zygotes. This technology has helped identify phenotypes associated with germline or somatic mutants of Polβ. Such KI mouse models have helped uncover the importance of key Polβ active site residues or specific Polβ enzyme activities, such as the <i>Polb</i>^Y265C mouse that develops lupus symptoms. More recently, we have used this KI technology to mutate the <i>Polb</i> gene with two codon changes, yielding the <i>Polb</i>^L301R/V303R mouse. In this KI mouse model, the expressed Polβ protein cannot bind to its obligate heterodimer partner, Xrcc1. Although the expressed mutant Polβ protein is proteolytically unstable and defective in recruitment to sites of DNA damage, the homozygous <i>Polb</i>^L301R/V303R mouse is viable and fertile, yet small in stature. We expect that this and additional targeted mouse models under development are poised to reveal new biological and organismic roles for Polβ.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 S1","pages":"57-71"},"PeriodicalIF":2.8,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140556279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interlaboratory validation of the ToxTracker assay: An in vitro reporter assay for mechanistic genotoxicity assessment","authors":"Giel Hendriks,&nbsp;Els Adriaens,&nbsp;Ashley Allemang,&nbsp;Julie Clements,&nbsp;Gabrielle Cole,&nbsp;Remco Derr,&nbsp;Maria Engel,&nbsp;Annie Hamel,&nbsp;Darren Kidd,&nbsp;Stephanie Kellum,&nbsp;Tomomi Kiyota,&nbsp;Abby Myhre,&nbsp;Valerie Naëssens,&nbsp;Stefan Pfuhler,&nbsp;Marise Roy,&nbsp;Raja Settivari,&nbsp;Maik Schuler,&nbsp;Andreas Zeller,&nbsp;Jan van Benthem,&nbsp;Philippe Vanparys,&nbsp;David Kirkland","doi":"10.1002/em.22592","DOIUrl":"10.1002/em.22592","url":null,"abstract":"<p>ToxTracker is a mammalian cell reporter assay that predicts the genotoxic properties of compounds with high accuracy. By evaluating induction of various reporter genes that play a key role in relevant cellular pathways, it provides insight into chemical mode-of-action (MoA), thereby supporting discrimination of direct-acting genotoxicants and cytotoxic chemicals. A comprehensive interlaboratory validation trial was conducted, in which the principles outlined in OECD Guidance Document 34 were followed, with the primary objectives of establishing transferability and reproducibility of the assay and confirming the ability of ToxTracker to correctly classify genotoxic and non-genotoxic compounds. Reproducibility of the assay to predict genotoxic MoA was confirmed across participating laboratories and data were evaluated in terms of concordance with in vivo genotoxicity outcomes. Seven laboratories tested a total of 64 genotoxic and non-genotoxic chemicals that together cover a broad chemical space. The within-laboratory reproducibility (WLR) was up to 98% (73%–98% across participants) and the overall between-laboratory reproducibility (BLR) was 83%. This trial confirmed the accuracy of ToxTracker to predict in vivo genotoxicants with a sensitivity of 84.4% and a specificity of 91.2%. We concluded that ToxTracker is a robust in vitro assay for the accurate prediction of in vivo genotoxicity. Considering ToxTracker's robust standalone accuracy and that it can provide important information on the MoA of chemicals, it is seen as a valuable addition to the regulatory in vitro genotoxicity battery that may even have the potential to replace certain currently used in vitro battery assays.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 1-2","pages":"4-24"},"PeriodicalIF":2.8,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/em.22592","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140305294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigations on the genotoxic potential of styrene in Fischer 344 rats using multiple endpoints","authors":"B. Bhaskar Gollapudi","doi":"10.1002/em.22590","DOIUrl":"10.1002/em.22590","url":null,"abstract":"<p>Genotoxicity of styrene monomer was evaluated in male Fischer 344 rats using the alkaline comet assay for DNA damage, micronucleus assay for cytogenetic damage and the <i>Pig-a</i> assay for gene mutations. In a dose range finding (DRF) study, styrene was administered by oral gavage in corn oil for 28 consecutive days at 0, 100, 500, and 1000 mg/kg/day. The bioavailability of styrene was confirmed in the DRF by measuring its plasma levels at approximately 7- or 15-min following dosing. The 1000 mg/kg/day group exceeded the maximum tolerated dose based on body weight and organ weight changes and signs of central nervous system depression. Based on these findings, doses of 0, 100, 250, and 500 mg/kg/day (for 28 or 29 days) were selected for the genotoxicity assays. Animals were sacrificed 3–4 h after treatment on Day 28 or 29 for assessing various genotoxicity endpoints. <i>Pig-a</i> mutant frequencies and micronucleus frequencies were determined in peripheral blood erythrocytes. The comet assay was conducted in the glandular stomach, duodenum, liver, lung, and kidney. These studies were conducted in accordance with the relevant OECD test guidelines. Oral administration of styrene did not lead to genotoxicity in any of the investigated endpoints. The adequacy of the experimental conditions was assured by including animals treated by oral gavage with the positive control chemicals ethyl nitrosourea and ethyl methane sulfonate. Results from these studies supplement to the growing body of evidence suggesting the lack of in vivo genotoxic potential for styrene.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 1-2","pages":"67-75"},"PeriodicalIF":2.8,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/em.22590","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140206528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Firefighting, per- and polyfluoroalkyl substances, and DNA methylation of genes associated with prostate cancer risk","authors":"Margaret Quaid,&nbsp;Jaclyn M. Goodrich,&nbsp;Miriam M. Calkins,&nbsp;Judith M. Graber,&nbsp;Derek Urwin,&nbsp;Jamie Gabriel,&nbsp;Alberto J. Caban-Martinez,&nbsp;Rebekah L. Petroff,&nbsp;Casey Grant,&nbsp;Shawn C. Beitel,&nbsp;Sally Littau,&nbsp;John J. Gulotta,&nbsp;Darin Wallentine,&nbsp;Jeff Hughes,&nbsp;Jefferey L. Burgess","doi":"10.1002/em.22589","DOIUrl":"10.1002/em.22589","url":null,"abstract":"<p>Prostate cancer is the leading incident cancer among men in the United States. Firefighters are diagnosed with this disease at a rate 1.21 times higher than the average population. This increased risk may result from occupational exposures to many toxicants, including per- and polyfluoroalkyl substances (PFAS). This study assessed the association between firefighting as an occupation in general or PFAS serum levels, with DNA methylation. Only genomic regions previously linked to prostate cancer risk were selected for analysis: <i>GSTP1</i>, Alu repetitive elements, and the 8q24 chromosomal region. There were 444 male firefighters included in this study, with some analyses being conducted on fewer participants due to missingness. Statistical models were used to test associations between exposures and DNA methylation at CpG sites in the selected genomic regions. Exposure variables included proxies of cumulative firefighting exposures (incumbent versus academy status and years of firefighting experience) and biomarkers of PFAS exposures (serum concentrations of 9 PFAS). Proxies of cumulative exposures were associated with DNA methylation at 15 CpG sites and one region located within <i>FAM83A</i> (<i>q</i>-value &lt;0.1). SbPFOA was associated with 19 CpG sites (<i>q</i> &lt; 0.1), but due to low detection rates, this PFAS was modeled as detected versus not detected in serum. Overall, there is evidence that firefighting experience is associated with differential DNA methylation in prostate cancer risk loci, but this study did not find evidence that these differences are due to PFAS exposures specifically.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 1-2","pages":"55-66"},"PeriodicalIF":2.8,"publicationDate":"2024-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/em.22589","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140206527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Qualitative and quantitative changes in mitochondrial DNA associated with cervical cancer: A comprehensive review","authors":"Isadora Oliveira Ansaloni Pereira,&nbsp;Nayara Nascimento Toledo Silva,&nbsp;Angelica Alves Lima,&nbsp;Glenda Nicioli da Silva","doi":"10.1002/em.22591","DOIUrl":"10.1002/em.22591","url":null,"abstract":"<p>Cervical cancer is the fourth most commonly diagnosed cancer in women and is considered a preventable disease, as vaccination and screening programs effectively reduce its incidence and mortality rates. Disease physiopathology and malignant cell transformation is a complex process, but it is widely known that high-risk HPV (hrHPV) infection is a necessary risk factor for cancer development. Mitochondria, cell organelles with important bioenergetic and biosynthetic functions, are important for cell energy production, cell growth, and apoptosis. Mitochondrial DNA is a structure that is particularly susceptible to quantitative (mtDNA copy number variation) and qualitative (sequence variations) alterations that are associated with various types of cancer. Novel biomarkers with diagnostic and prognostic value in cervical cancer can be evaluated to provide higher specificity and complement hrHPV molecular testing, which is the most recommended method for primary screening. In accordance with this, this review aimed to assess mitochondrial alterations associated with cervical cancer in clinical cervicovaginal samples, in order to unravel their possible role as specific diagnostic and prognostic biomarkers for cervical malignancy, and also to guide the understanding of their involvement in carcinogenesis, HPV infection, and disease progression.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 3-4","pages":"143-152"},"PeriodicalIF":2.8,"publicationDate":"2024-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140206529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urinary mutagenicity and bladder cancer risk in northern New England","authors":"Jason Y. Y. Wong,&nbsp;Alexander H. Fischer,&nbsp;Dalsu Baris,&nbsp;Laura E. Beane Freeman,&nbsp;Margaret R. Karagas,&nbsp;Molly Schwenn,&nbsp;Alison Johnson,&nbsp;Peggy P. Matthews,&nbsp;Adam E. Swank,&nbsp;G. Monawar Hosain,&nbsp;Stella Koutros,&nbsp;Debra T. Silverman,&nbsp;David M. DeMarini,&nbsp;Nathaniel Rothman","doi":"10.1002/em.22588","DOIUrl":"10.1002/em.22588","url":null,"abstract":"<p>The etiology of bladder cancer among never smokers without occupational or environmental exposure to established urothelial carcinogens remains unclear. Urinary mutagenicity is an integrative measure that reflects recent exposure to genotoxic agents. Here, we investigated its potential association with bladder cancer in rural northern New England. We analyzed 156 bladder cancer cases and 247 cancer-free controls from a large population-based case–control study conducted in Maine, New Hampshire, and Vermont. Overnight urine samples were deconjugated enzymatically and the extracted organics were assessed for mutagenicity using the plate-incorporation Ames assay with the <i>Salmonella</i> frameshift strain YG1041 + S9. Logistic regression was used to estimate the odds ratios (OR) and 95% confidence intervals (CI) of bladder cancer in relation to having mutagenic versus nonmutagenic urine, adjusted for age, sex, and state, and stratified by smoking status (never, former, and current). We found evidence for an association between having mutagenic urine and increased bladder cancer risk among never smokers (OR = 3.8, 95% CI: 1.3–11.2) but not among former or current smokers. Risk could not be estimated among current smokers because nearly all cases and controls had mutagenic urine. Urinary mutagenicity among never-smoking controls could not be explained by recent exposure to established occupational and environmental mutagenic bladder carcinogens evaluated in our study. Our findings suggest that among never smokers, urinary mutagenicity potentially reflects genotoxic exposure profiles relevant to bladder carcinogenesis. Future studies are needed to replicate our findings and identify compounds and their sources that influence bladder cancer risk.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 1-2","pages":"47-54"},"PeriodicalIF":2.8,"publicationDate":"2024-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/em.22588","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140093598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genotoxicity in humans exposed to arsenic, lithium, and boron in drinking water in the Bolivian Andes—A cross sectional study","authors":"Noemi Tirado,&nbsp;Josué Mamani,&nbsp;Jessica De Loma,&nbsp;Franz Ascui,&nbsp;Karin Broberg,&nbsp;Jacques Gardon","doi":"10.1002/em.22587","DOIUrl":"10.1002/em.22587","url":null,"abstract":"<p>Elevated concentrations of arsenic, lithium and boron in drinking water have already been reported in Bolivia. Arsenic is known to cause genotoxicity but that caused by lithium and boron is less well known. The aim of the present cross-sectional study was to evaluate potential genotoxic effects of exposure to arsenic, while considering exposure to lithium and boron and genetic susceptibility. Women (<i>n</i> = 230) were recruited in villages located around Lake Poopó. Exposure to arsenic was determined as the sum of concentrations of arsenic metabolites inorganic arsenic, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in urine. Exposure to lithium and boron was determined based on their concentrations in urine. Genetic susceptibility was determined by <i>GSTM1</i> (glutathione S-transferase-mu-1) and <i>GSTT1</i> (glutathione S-transferase-theta-1) null genotypes and <i>AS3MT</i> (Arsenite Methyltransferase) rs3740393. Genotoxicity was measured in peripheral blood leukocytes using the comet assay. The geometric means of arsenic, lithium, and boron concentrations were 68, 897, and 3972 μg/L, respectively. <i>GSTM1</i> and <i>GSTT1</i> null carriers had more DNA strand breaks than gene carriers (<i>p</i> = .008, <i>p</i> = .005). We found no correlation between urinary arsenic and DNA strand breaks (<i>r</i>_S = .03, <i>p</i> = .64), and only a weak non-significant positive association in the adjusted multivariate analysis (β = .09 [−.03; .22], <i>p</i> = .14). Surprisingly, increasing concentrations of lithium in urine were negatively correlated with DNA strand breaks (<i>r</i>_S = −.24, <i>p</i> = .0006), and the association persisted in multivariate analysis after adjusting for arsenic (β = −.22 [−.36; −.08], <i>p</i> = .003). We found no association between boron and DNA strand breaks. The apparent protective effect of lithium merits further investigation.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 3-4","pages":"121-128"},"PeriodicalIF":2.8,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/em.22587","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139930602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cytogenotoxicity effects in addicts with multidrug consumption","authors":"Ana Elizabeth González-Santiago,&nbsp;Alejandro Salvador Gómez-Cabrera,&nbsp;Raúl Cuauhtémoc Baptista-Rosas,&nbsp;Guillermo Moisés Zúñiga-González,&nbsp;Belinda Claudia Gómez-Meda,&nbsp;Ana Alondra Sobrevilla Navarro,&nbsp;María Guadalupe Sánchez-Parada","doi":"10.1002/em.22584","DOIUrl":"10.1002/em.22584","url":null,"abstract":"<p>Drug abuse is considered a global health problem with serious social impact. In recent decades, changes in drug consumption patterns have shown a clear rising trend in the use of multiple drugs. Although the buccal micronucleus cytome (BMCyt) assay has evaluated cytotoxicity in drug abuse, there has not been an approach that takes into account this pattern of multiple drug use. Therefore, in this study, we evaluate for the first time the cytogenotoxic effects in multidrug users, and its correlation with the amount consumed and years of abuse. This study was conducted on 166 individuals by the BMCyt assay. A total of 83 individuals with a history of multiple licit (alcohol and tobacco) and at least one illicit drug abuse (marijuana, methamphetamines, cocaine, and/or inhalants), and 83 healthy individuals, non-drug abusers were analyzed. The results showed that drug abusers had higher frequencies of nuclear abnormalities nuclear buds, binucleated cells, pyknotic nuclei (PNs), karyorrhexis (KX), and abnormally condensed chromatin when compared with healthy controls. Moreover, results suggests that the use of licit and illicit drugs is related to cytogenotoxic damage, as was shown by an upward trend in the frequency of nuclear abnormalities identified in groups 1 (alcohol + tobacco + at least one illicit drug) and 2 (tobacco + at least one illicit drug). Furthermore, a positive correlation was found in the different groups, between the years and the amount of consumption of some drugs (alcohol, methamphetamine, and tobacco) with cytotoxicity markers such as KL, KX, and PNs.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 1-2","pages":"84-95"},"PeriodicalIF":2.8,"publicationDate":"2024-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139729328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Veterinarians exposed to inhaled anesthetic present chromosome damage, apoptosis and cell cycle changes","authors":"Mariana G. Braz,&nbsp;Drielle B. S. Figueiredo,&nbsp;Marjorie A. Golim,&nbsp;Tony F. Grassi,&nbsp;Bruno R. B. da Costa,&nbsp;Bruno S. De Martinis,&nbsp;Leandro G. Braz","doi":"10.1002/em.22586","DOIUrl":"10.1002/em.22586","url":null,"abstract":"<p>This cross-sectional study evaluated, for the first time, DNA damage, viability, and cell death of lymphocytes and cell cycle phases of mononuclear and polymorphonuclear cells in veterinarians exposed to the volatile anesthetic isoflurane. Veterinarians who were occupationally exposed to isoflurane (exposed group; <i>n</i> = 20) and matched-unexposed individuals (volunteers without occupational exposure; <i>n</i> = 20) were enrolled in the study. DNA damage was assessed in lymphocytes by micronucleus (MN) and phosphorylated histone gamma-H2AX (γ-H2AX). Cell viability, cytotoxicity, and the cell cycle were evaluated by flow cytometry. Isoflurane was detected in urine samples by headspace gas chromatography–mass spectrometry. Compared with unexposed subjects, veterinarians occupationally exposed to isoflurane (25.7 ± 23.7 μg/L urine) presented statistically higher MN frequencies, lymphocytic apoptosis rates, and numbers of polymorphonuclear cells in the G0/G1 stage. Additionally, the exposed group presented statistically lower proportions of viable lymphocytes and G2/M polymorphonuclear cells. Our findings indicate that veterinarians who are frequently exposed to inhaled anesthetic exhibit chromosomal and cell damage in addition to changes in peripheral blood cell proliferation.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 1-2","pages":"96-102"},"PeriodicalIF":2.8,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139706347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of micronucleus induction and DNA damage biomarkers in TK6 and A375 cells using flow cytometry","authors":"Xiaowen Sun,&nbsp;Richard A. Spellman,&nbsp;Maria Engel,&nbsp;Elizabeth Rubitski,&nbsp;Maik Schuler","doi":"10.1002/em.22585","DOIUrl":"10.1002/em.22585","url":null,"abstract":"<p>Previously, we introduced an alternative adherent A375 cell line for clastogenicity and aneugenicity testing using a high content imaging platform. To further characterize the performance of A375 cells, we investigated the sensitivity and specificity of A375 and TK6 cells by directly comparing micronucleus (MN) induction, cytotoxicity (relative cell counts, viability, and apoptosis), clastogenicity (γH2AX), and aneuploidy markers (pH 3, MPM-2, and polyploidy) using flow cytometric methods. We evaluated 14 compounds across different mechanisms (non-genotoxic apoptosis inducers, clastogens, and aneugens with either tubulin binding or aurora kinase inhibiting phenotypes) at 4-h and 24-h post treatment. Both aneugens and clastogens tested positive for micronucleus induction in both cell lines. Apoptosis continued to be a confounding factor for flow cytometry-based micronuclei assessment in TK6 cells as evidenced by positive responses by the three cytotoxicants. Conversely, A375 cells were not affected by apoptosis-related false positive signals and did not produce a positive response in the in vitro micronucleus assay. Benchmark dose response (BMD) analysis showed that the induction of micronuclei and biomarkers occurred at similar concentrations in both cell lines for clastogens and aneugens. By showing that A375 cells have similar sensitivity to TK6 cells but a greater specificity, these results provide additional support for A375 cells to be used as an alternative adherent cell line for in vitro genetic toxicology assessment.</p>","PeriodicalId":11791,"journal":{"name":"Environmental and Molecular Mutagenesis","volume":"65 1-2","pages":"25-46"},"PeriodicalIF":2.8,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/em.22585","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139706346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}