Mutation research. Genetic toxicology and environmental mutagenesis最新文献

{"title":"Aminated polystyrene and DNA strand breaks in A549, Caco-2, THP-1 and U937 human cell lines","authors":"Yuxin Liu,&nbsp;Peter Møller ,&nbsp;Martin Roursgaard","doi":"10.1016/j.mrgentox.2025.503865","DOIUrl":"10.1016/j.mrgentox.2025.503865","url":null,"abstract":"<div><div>Plastic is used extensively worldwide. However, plastic particles that are less than 1000 nm (i.e. nanoplastics) may be hazardous to human cells. Nanoplastics might be manufactured intentionally or be formed in the environment by degradation of larger plastic items. Ingestion and inhalation are the two most common routes of human exposure to nanoplastics, indicating that epithelial cells have direct exposure. However, immune cells will also interact with particles during tissue inflammation. An assessment of published studies suggests that polystyrene (PS) particles generate higher levels of DNA damage in immune cells compared to epithelial cells, although it has not been formally studied under the same experimental condition. To investigate this, we assessed cytotoxicity, oxidative stress and DNA strand breaks in lung epithelial (A549) cells, intestinal epithelial (Caco-2) cells, and two monocytes (THP-1 and U937) after exposure to amine-functionalized polystyrene particles (PS-NH₂) with declared particle size of 240 nm. No cytotoxicity or intracellular reactive oxygen species production were found at concentrations up to 200 µg/mL. Exposure to PS-NH₂ was associated with glutathione depletion in A549 cells. However, there was no increase in the level of DNA strand breaks, measured by the comet assay, in any of the cell lines under standard assay conditions. Diethyl maleate treatment was used to render cells susceptible to oxidative stress. By itself, diethyl maleate treatment led to approximately 50 % glutathione depletion and increased DNA strand breaks, but additional DNA damage was not observed in cells by PS-NH₂ exposure in A549, Caco-2, THP-1 and U937 cells.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"903 ","pages":"Article 503865"},"PeriodicalIF":2.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576939","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":"The dose-, LET-, and gene-dependent patterns of intragenic DNA changes underlying recessive visible mutations at the autosomal gene cinnabar of Drosophila melanogaster","authors":"I.D. Alexandrov,&nbsp;M.V. Alexandrova,&nbsp;K.P. Afanasyeva,&nbsp;N.E. Kharchenko","doi":"10.1016/j.mrgentox.2025.503857","DOIUrl":"10.1016/j.mrgentox.2025.503857","url":null,"abstract":"<div><div>Sequence analysis of 2 spontaneous, 26 γ-ray- and 10 neutron/neutron + γ-ray-induced <em>cn</em> gene/point mutants was performed. One spontaneous mutant had the entire maternal <em>сn</em>^<em>1</em> sequence studied (4644 bp, full gene conversion). The second mutant contained cluster of DNA changes consisting of a partial gene conversion (tract length of 1087 bp), as well as an extended deletion (47 bp) and one single-base substitution in exon 2. Almost the same spectra of DNA changes in γ-ray- and neutron/neutron + γ-ray-induced <em>cn</em> mutants made it possible to unite them into one group of 36 radiation-induced mutants. Among the 36 mutants studied, 5 mutants (13.9 %) did’t have any DNA changes within the studied sequence of the <em>cn</em> genomic region. The 31 remaining mutants contained 36 DNA changes. There were 3 (8.3 %) single-base substitutions, 2 (5.5 %) frameshifts or indels 1–3-bp long, 14 (38.9 %) extended deletions of 5–21 bp in length, 12 (33.3 %) gene conversion events, 2 (5.5 %) large insertion (∼ 6.0 kb) of unidentified origin, and 1 (2.8 %) large (640 bp) deletion, 1 (2.8 %) extended insertion (8 bp), 1 (2.8 %) insertion/duplication (505 bp). Among 12 gene conversion events, there were 7 full and 5 partial events. The tract length in the mutants with partial conversion varies from 44 to 2247 bp. According to literature data such DNA changes as gene conversion, extended deletions, and indels must be the products of homologous recombination, single-strand annealing, and non-homologous ends joining repair pathways, respectively. We propose that the initial DNA lesions for DNA changes are different types of DNA double-strand breaks (DSB): (i) complex DSBs, (ii) less complex DSBs, and (iii) simple DSBs. Comparing the spectrum of DNA changes in the <em>cn</em> gene/point mutants with that in <em>black</em> one, it is important to note that the ratio of DNA changes in various genomic regions may be different.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"903 ","pages":"Article 503857"},"PeriodicalIF":2.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529363","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":"AI/ML modeling to enhance the capability of in vitro and in vivo tests in predicting human carcinogenicity","authors":"Ani Tevosyan ,&nbsp;Hrach Yeghiazaryan ,&nbsp;Gohar Tadevosyan ,&nbsp;Lilit Apresyan ,&nbsp;Vahe Atoyan ,&nbsp;Anna Misakyan ,&nbsp;Zaven Navoyan ,&nbsp;Helga Stopper ,&nbsp;Nelly Babayan ,&nbsp;Lusine Khondkaryan","doi":"10.1016/j.mrgentox.2025.503858","DOIUrl":"10.1016/j.mrgentox.2025.503858","url":null,"abstract":"<div><div>This study aimed to develop an in silico model for predicting human carcinogenicity using advanced deep learning techniques, specifically Graph Neural Networks (GNN), through a multitask learning (MTL) approach. The MTL framework leveraged auxiliary tasks, including mutagenicity, genotoxicity, animal carcinogenicity, androgen and estrogen receptor binding, to enhance the model's predictive capabilities for the primary task of human carcinogenicity. Three distinct GNN architectures were used alongside various combinations of auxiliary tasks to evaluate the variations in performance metrics. Results demonstrated that multitask learning significantly enhances the predictive performance of GNN models compared to single-task learning for predicting human carcinogenicity. The best performed MTL model achieved an area under the curve of 0.89, along with a balanced accuracy of 82 %, and sensitivity and specificity values of 0.75 and 0.89, respectively. The developed multitask learning (MTL) models function on tasks that represent assays for identifying both genotoxic and non-genotoxic carcinogens, thereby enhancing the model's capability to predict human carcinogenic risk with greater accuracy. The advanced GNN models demonstrated effectiveness in addressing data imbalance issues frequently observed in biological datasets, mitigating the bias that typically favors one class over another. Overall, these results underscore the promise of GNN-based MTL models for reliable chemical screening and prioritization, particularly in predicting human carcinogenicity.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"903 ","pages":"Article 503858"},"PeriodicalIF":2.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549444","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":"Safety evaluation of ethanolic extract from aerial flowering part of spiny globe thistle (Echinops spinosus) in mice: Phytochemical screening and genotoxicity","authors":"Kawthar A. Diab ,&nbsp;Maha A. Fahmy ,&nbsp;Entessar E. Hassan ,&nbsp;Ahmed M. Nagy ,&nbsp;Ayman A. Farghaly ,&nbsp;Emad M. Hassan ,&nbsp;Enayat A. Omara","doi":"10.1016/j.mrgentox.2025.503854","DOIUrl":"10.1016/j.mrgentox.2025.503854","url":null,"abstract":"<div><div><em>Echinops spinosus</em> is widely used by the population due to its therapeutic potential; however, there is no evidence in the literature that substantiates its safety. Therefore, this study aimed to identify the chemical constituents of <em>E. spinosus</em> extract via GC/MS analysis and evaluate its cytotoxicity and genotoxicity. Male mice were orally given three doses of <em>E. spinosus</em> extract (250, 500, and 1000 mg/kg) for four weeks. Blood and tissue samples were collected after the end of treatment. GC–MS results revealed 73 compounds in the <em>E. spinosus</em> extract, including sugars, sugar alcohols, fatty acids, organic acids, amino acids, and nitrogenous compounds. <em>In vitro</em> experiments revealed that <em>E. spinosus</em> was not cytotoxic to human colon, prostate, or breast cancer cells. <em>In vivo</em> experiments showed that <em>E. spinosus</em> extract did not significantly induce chromosomal damage in the bone marrow, primary spermatocyte, or sperm morphology abnormalities at doses up to 1000 mg/kg/day. This extract also did not induce DNA damage at doses <em>≤ 500 mg/kg/day</em> in the bone marrow, spleen, testis, or spermatozoa and at 250 mg/kg/day in the liver or kidney. However, treatment with a high dose of <em>E. spinosus</em> caused significant disturbances in liver and kidney functions, oxidative stress indicators, comet tail formation, and histological architecture of the liver, kidney, and testis. In conclusion<em>, E. spinosus</em> extract is nontoxic, with an oral LD₅₀ &gt; 5000 mg/kg. The extract showed negative genotoxicity within the safety threshold of ≤ 500 mg/kg/day and positive genotoxicity at a dose of 1000 mg/kg/day.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"902 ","pages":"Article 503854"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376923","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":"Dose-response curve for induction of unstable chromosome aberrations by 6 MV linear accelerator photons: Analysis of intra-experimental variations","authors":"Volodymyr Vinnikov ,&nbsp;Dominika Kochanova ,&nbsp;Katarína Vigašová ,&nbsp;Sachin Gulati ,&nbsp;Matúš Durdík ,&nbsp;Pavol Košík ,&nbsp;Eva Marková ,&nbsp;Lukáš Jakl ,&nbsp;Lucián Zastko ,&nbsp;Kristína Kontrišová ,&nbsp;Igor Belyaev","doi":"10.1016/j.mrgentox.2025.503849","DOIUrl":"10.1016/j.mrgentox.2025.503849","url":null,"abstract":"<div><div>Cytogenetic biodosimetry relies on dose-response curves (DRCs) for each type of radiation that can cause a radiation emergency. We have constructed a DRC based on the dicentric assay. Blood samples from four healthy volunteers were irradiated with acute 6 MV linac photons, 0.46–4.55 Gy; 0.68 and 1.37 Gy doses were used in the ‘blind’ validation study. Lymphocytes were cultured with variations in time delay in mitogenic stimulation after irradiation (2 vs. 16 h) and mitotic arrest by colchicine (3.5 vs. 16 h). Aberrations were scored in the first division metaphases, ensured by fluorescence-plus-Giemsa staining. DRCs for dicentrics and dicentrics plus centric rings were efficiently fitted using the linear-quadratic model. We show, for the first time, that neither prolonged mitotic arrest nor delayed mitogenic stimulation has any effect on DRC. However, the latter factor caused a significant increase in the yield of the second division metaphase in culture. Inter-donor differences in the DRC for aberrations were not large, but individual changes in the frequencies of second-division cells were highly variable. In the validation study, the DRC combined from all experimental series provided dose estimates that were as accurate as those, obtained using the donors’ individual or culture-type specific DRCs. The DRC coefficients in present study were slightly higher than those reported previously for linac beams and close to values for orthovoltage X-rays. Further cytogenetic studies of megavoltage radiation beams require stringent standardization of experimental conditions.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"902 ","pages":"Article 503849"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152748","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":"What are the effects of whole blood storage conditions on comet assay in terms of DNA damage and repair?","authors":"Eren Ozcagli ,&nbsp;Esma Soylemez Yesilcimen ,&nbsp;Gulden Zehra Omurtag","doi":"10.1016/j.mrgentox.2025.503851","DOIUrl":"10.1016/j.mrgentox.2025.503851","url":null,"abstract":"<div><div>The comet assay is a rapid, simple and sensitive method for the detection of DNA damage and repair at the level of individual cells, with a wide range of applications in human biomonitoring and molecular epidemiology. It is common practice to perform the comet assay on fresh samples to preserve the integrity of the DNA and to obtain reliable results, which is why most published studies have been designed using fresh blood samples. There are limitations associated with the use of fresh samples for this assay and the need for appropriate storage for some studies. The aim of this study was to determine changes in DNA damage and DNA repair kinetics during medium- and long-term storage of human whole blood (WB) samples without adding cryopreservatives. Whole blood samples were divided into small portions and tested after overnight storage at + 4 °C. Frozen samples were stored at −20 and −80 °C for 3 different time points: 30, 90 and 180 days. Frozen samples were compared with fresh samples stored at + 4 °C in terms of DNA damage and repair. For WB samples stored at −80 °C, showed an increase in purine base damage (PBD) and DNA repair alterations were determined while no increase in basal DNA damage was observed. According to the results of our study, storage of WB samples for comet assay in small portions at −20 °C for up to 90 days does not cause any additional damage and does not cause any alter DNA repair kinetics.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"902 ","pages":"Article 503851"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152750","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":"Genotoxic and cytotoxic effects of polystyrene nanoplastics on human lymphocytes: A comprehensive analysis","authors":"Ahmet Ali Berber ,&nbsp;Nihan Akinci Kenanoğlu ,&nbsp;Şefika Nur Demi̇r ,&nbsp;Hüseyin Aksoy","doi":"10.1016/j.mrgentox.2025.503850","DOIUrl":"10.1016/j.mrgentox.2025.503850","url":null,"abstract":"<div><div>A growing amount of plastic waste is finding its way into natural ecosystems as a result of the widespread usage of plastics in modern society. These wastes degrade physically and biologically over time, transforming into microplastics (MPs) and nanoplastics (NPs). MPs and NPs emissions from the terrestrial environment then mix with rivers and eventually the seas, forming garbage. The cytotoxic and genotoxic effects of 50 nm polystyrene nanoplastics (PsNP) on human lymphocytes were assessed using the in vitro mitotic index (MI), micronucleus (MN), and comet assays. Both 24 and 48-h applications were performed for MI, and it was determined that 50 nm PsNP provided a statistically significant decrease in MI compared to the control at all concentrations and application times (except 0.001 and 0.1 μg/mL at 24 h). According to the MN test results, the MN frequency increased significantly at all concentrations when compared to the negative control. In the comet test, a statistically significant increase of comet tail length was observed at 0.001, 10 and 100 μg/mL concentration with 50 nm PsNP exposure. Tail moment also showed a statistically significant increase at the lowest concentration of 0.001 μg/mL and the highest concentration of 1, 10, 100 μg/mL compared to the negative control. All test results show that PsNP has both genotoxic and cytotoxic potential.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"902 ","pages":"Article 503850"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152747","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":"The role of luteolin in modulation of acrylamide-induced genotoxicity and apoptosis in embryonic fibroblast cells","authors":"Burcu Keskin ,&nbsp;Banu Orta-Yilmaz ,&nbsp;Yasemin Aydin","doi":"10.1016/j.mrgentox.2025.503853","DOIUrl":"10.1016/j.mrgentox.2025.503853","url":null,"abstract":"<div><div>Acrylamide (Acr) is generated through cooking techniques such as frying and roasting, commonly employed in food preparation. The consumption of Acr is unavoidable due to its prevalence in frequently consumed food products. Awareness of the detrimental consequences of Acr has prompted researchers to undertake experiments aimed at mitigating these effects. Flavonoids, the secondary metabolites of plants, have been researched for their antioxidant properties. Luteolin (Lut) exhibits higher antioxidant potency compared to many other flavonoids and has also shown strong DNA-protective properties in the previous research. The study involved the administration of Acr (0.5, 1, and 2 mM) and Lut (10 µM) to Balb/c 3T3 embryonic fibroblast cells for 24 h. The cytotoxic effect of Acr and Lut on 3T3 embryonic fibroblast cells was assessed using cell viability and lactate dehydrogenase assays. Furthermore, the propidium iodide/Hoechst double fluorescence staining technique was employed to illustrate the apoptotic consequences. The genotoxicity of Acr and the cytoprotective properties of Lut against this genotoxicity were evaluated using cytokinesis-blocking micronucleus analysis and the comet test. The analysis of the results revealed that exposure of embryonic fibroblast cells to Acr concentrations led to a significant reduction in cell viability, along with an elevation in lactate dehydrogenase enzyme levels, an increase in the frequency of micronuclei, and the formation of comets. Additionally, Lut has been shown to suppress both cytotoxicity and genotoxicity when used in combination with Acr. Consequently, it has been revealed that Lut has ameliorative effects on genotoxicity caused by Acr.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"902 ","pages":"Article 503853"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152751","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":"A comparative analysis of select P450 enzymes in uninduced and PB/BNF-induced hamster and rat liver S9","authors":"Kristie Evans ,&nbsp;Slaydon Boitnotte ,&nbsp;Errol Zeiger ,&nbsp;Jennifer Cheung ,&nbsp;Anthony Lynch","doi":"10.1016/j.mrgentox.2025.503855","DOIUrl":"10.1016/j.mrgentox.2025.503855","url":null,"abstract":"<div><div>The assessment of potentially carcinogenic <em>N</em>-nitrosamine impurities in drugs has become crucial for the pharmaceutical industry to ensure public safety. The <em>in vitro</em> Ames test, which uses rat or hamster liver S9 for metabolic activation, is an important component of regulatory test batteries for assessing mutagenicity and has been the traditional method for assessing the potential mutagenicity of chemicals, including <em>N</em>-nitrosamines. This test, however, has shown inconsistencies with some <em>N</em>-nitrosamines, raising concerns about the liver S9's ability to activate <em>N</em>-nitrosamines to their proximate mutagens. Assays from Vivid® CYP450 Screening Kits and the 7-benzyloxyquinoline assay were used to measure substrate activities of P450 enzymes involved in <em>N</em>-nitrosamine metabolism in rat and hamster liver S9. Both uninduced and induced rat and hamster liver S9 preparations were used. The results provide a comparative assessment of the metabolic competency of the rodent S9s to metabolize <em>N</em>-nitrosamines to their mutagenic forms. Hamster S9 consistently showed increased CYP activity compared to rat S9 under the same conditions. Induced rat S9 also displayed relatively high conversion levels, with the greatest increase in 7-benzyloxyquinoline conversion (CYP3A-like activity) over uninduced (15.7-fold). The highest increase observed with induced hamster S9 was for CYP2A6-like activity which was induced over 7.8-fold and was ∼60-fold higher in induced hamster S9 compared to induced rat S9. These results demonstrate that both rat and hamster S9 contain relevant P450 enzyme activities for <em>N</em>-nitrosamine bioactivation, but hamster S9 is recommended for nitrosamine <em>in vitro</em> tests due to its overall higher P450 activity levels.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"902 ","pages":"Article 503855"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395970","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":"Fibroblast-based radiosensitivity assays as a clinically valuable tool for (severe) combined immunodeficiency syndromes","authors":"Elien Beyls ,&nbsp;Somara De Beul ,&nbsp;Victoria Bordon ,&nbsp;Alina Ferster ,&nbsp;Filomeen Haerynck ,&nbsp;Anne Vral ,&nbsp;Ans Baeyens","doi":"10.1016/j.mrgentox.2025.503852","DOIUrl":"10.1016/j.mrgentox.2025.503852","url":null,"abstract":"<div><div>Genetic defects in one of the DNA double strand break (DSB) repair proteins lead to distinct human syndromes with severe clinical manifestations, including impaired neurological and immunological development, cancer proneness and sensitivity to ionizing radiation. Since diagnostic and therapeutic procedures frequently use DNA damaging agents, identification of radiosensitive individuals is imperative to optimize patient management. However, patients with a (severe) combined immunodeficiency (S)CID are often ineligible for lymphocyte-based radiosensitivity testing. Therefore, this study investigated the suitability of two fibroblast-based assays as alternative methods. DSB repair was evaluated following X-ray irradiation by an optimized cytokinesis-block micronucleus (MN) assay and the γH2AX focus test in fibroblasts from patients with a confirmed or suspected diagnosis of radiosensitive (S)CID. Using both assays, patients with a defect in Artemis were identified as radiosensitive while those with a RAG1/2 deficiency were not considered as radiosensitive. Although MN scoring was not feasible in irradiated fibroblasts deficient in XLF, LIG4 or NBS1, radiosensitivity could be readily demonstrated through impaired DNA DSB repair kinetics with the γH2AX focus assay in fibroblasts deficient in XLF or LIG4, but not in those deficient in NBS1. While both ATM defective fibroblasts clearly showed increased radiation-induced MN yields, one of the two fibroblast cell lines could not be identified as radiosensitive based on residual γH2AX focus levels. This study suggests that combining the fibroblast MN assay and γH2AX focus test can effectively exclude <em>in vitro</em> radiosensitivity in patients with a suspicion of radiosensitive (S)CID, particularly when lymphocyte-based radiosensitivity testing is not feasible.</div></div>","PeriodicalId":18799,"journal":{"name":"Mutation research. Genetic toxicology and environmental mutagenesis","volume":"902 ","pages":"Article 503852"},"PeriodicalIF":2.3,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143152749","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}