Use of micronucleus cytome assays with buccal cells for the detection of genotoxic effects: A systematic review and meta-analysis of occupational exposures to metals.

Micronucleus (MN) assays with buccal cells are at present widely used to investigate occupational exposures to genotoxic carcinogens. This article describes their use for the monitoring of metal exposed workers. We found in total 73 relevant articles, in the majority (97 %) increased MN and/or other nuclear anomalies were reported. Most studies were realized in South East Asia and South America. A variety of different occupations was studied including welders, electroplaters, painters, workers in battery recycling and production, tannery workers, dental technicians, miners, workers in foundries and smelters, and also subjects working in waste recycling, glass, aluminum and steel production. In many investigations the effects increased with the duration of the working period. The quality of individual studies was evaluated with a quality score tool. The number of cells was in most studies sufficient and DNA-specific stains were used. However, many studies have shortcomings, e.g. they focused solely on MN formation and did not evaluate anomalies, which provide additional information about the stability of the genetic material and acute cytotoxic effects. Only 35 % of the investigations contain quantitative information about exposures to metals and other toxicants. In 6 of these studies, correlations were observed between the concentrations of specific metals (As, Pb, Cr, Cd) in body fluids and MN frequencies. Taken together, the available data indicate that the MN assay can be used to detect chromosomal damage in metal exposed groups; furthermore, it enables also comparisons between subgroups differing in regard to their exposure and allows an estimation of the efficiency of protective measures. The exposure of workers to metals is currently controlled with chemical analytical measurements only, MN assays with buccal cells could contribute to further improve the safety at workplaces as they reflect the biological consequences including synergistic and antagonistic interactions between toxicants.

Arecoline in buccal cells reflects Areca nut dose.

Areca nut (AN) is a carcinogen; its chewing cessation is, therefore, of worldwide interest. However, cessation biomarkers are lacking. We sought to establish arecoline in chewers' buccal cells (BCs) as a biomarker for AN dose. Self-reported AN doses, expressed as the average AN load ("AANL"), the product of AN amount, chewing time, and chewing frequency, were correlated by regression analysis with chewers' BC arecoline, measured by liquid chromatography mass spectrometry. We then determined whether associations differed between Class 1 chewers (who consume AN alone or with slaked lime, leaf, and/or spices) and Class 2 chewers (who consume any combination of the aforementioned ingredients plus tobacco). Among the 103 chewers, 28 Class 1 and 39 Class 2 chewers had detectable arecoline levels, which were used for analyses. A linear regression of cube-root transformed AANL on equally transformed BC arecoline levels provided the best model fit; resulting slopes and corresponding correlation coefficients were 0.86 and 0.40 (p < 0.01) for all; 1.09 and 0.51 (p < 0.01) for Class 1 chewers; 0.35 and 0.17 (p = 0.29) for Class 2 chewers; and 0.94 and 0.45 (p < 0.01), and 0.79 and 0.37 (p = 0.08), respectively, for those who included or excluded lime. Relationships between AANL and BC arecoline levels were similar between chewers who included or excluded lime (p = 0.76), but less between chewing classes (p = 0.14). This provides confidence that BC arecoline can generally act as a reliable biomarker for AN dose, useful for estimating efficacy in AN cessation studies and population-based chewing assessments.

Mobile phone specific radiation disturbs cytokinesis and causes cell death but not acute chromosomal damage in buccal cells: Results of a controlled human intervention study.

Several human studies indicate that mobile phone specific electromagnetic fields may cause cancer in humans but the underlying molecular mechanisms are currently not known. Studies concerning chromosomal damage (which is causally related to cancer induction) are controversial and those addressing this issue in mobile phone users are based on the use of questionnaires to assess the exposure. We realized the first human intervention trial in which chromosomal damage and acute toxic effects were studied under controlled conditions. The participants were exposed via headsets at one randomly assigned side of the head to low and high doses of a UMTS signal (n = 20, to 0.1 W/kg and n = 21 to 1.6 W/kg Specific Absorption Rate) for 2 h on 5 consecutive days. Before and three weeks after the exposure, buccal cells were collected from both cheeks and micronuclei (MN, which are formed as a consequence of structural and numerical chromosomal aberrations) and other nuclear anomalies reflecting mitotic disturbance and acute cytotoxic effects were scored. We found no evidence for induction of MN and of nuclear buds which are caused by gene amplifications, but a significant increase of binucleated cells which are formed as a consequence of disturbed cell divisions, and of karyolitic cells, which are indicative for cell death. No such effects were seen in cells from the less exposed side. Our findings indicate that mobile phone specific high frequency electromagnetic fields do not cause acute chromosomal damage in oral mucosa cells under the present experimental conditions. However, we found clear evidence for disturbance of the cell cycle and cytotoxicity. These effects may play a causal role in the induction of adverse long term health effects in humans.

Human buccal epithelial cells as a model system for molecular analysis of DNA, RNA and protein.

We report use of human buccal epithelial cells as an easy model system for isolation and molecular analysis of genomic DNA, RNA, and protein to study any gene of interest by Polymerase Chain Reaction (PCR), RNA expression by Reverse Transcription-PCR (RT-PCR), protein-profiling, and expression by western blot as well as DNA-methylation by Msp I/Hpa II-restriction digestion. We used simple methods to isolate genomic DNA, RNA and protein from human buccal cells collected by oral swab and cultured them in-vitro. The microscopic observation of haematoxylin and eosin (EA-50) stained cells, genomic PCR of house-keeping genes (GAPDH and ß-actin), RT-PCR of GAPDH and ß-actin mRNAs and whole cell protein-profiling by Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) were carried out. Expression of ß-actin protein in supernatant and pellet fractions of the cells was determined by western blot analysis. MTT-assay was carried out to assess the cell viability and cell growth. Green Fluorescence Protein (GFP)-DNA was expressed in these cells by transient transfection. DNA-methylation in the genome was analyzed by Msp I/ Hpa II restriction digestion and agarose gel electrophoresis. Thus these methods can be used for molecular analysis of DNA, RNA and protein from the human buccal epithelial cells for studying and monitoring health, disease, population genetics/genomics and epidemiology under different conditions.

Development of an epigenetic age predictor for costal cartilage with a simultaneous somatic tissue differentiation system.

Age prediction from DNA has been a topic of interest in recent years due to the promising results obtained when using epigenetic markers. Since DNA methylation gradually changes across the individual's lifetime, prediction models have been developed accordingly for age estimation. The tissue-dependence for this biomarker usually necessitates the development of tissue-specific age prediction models, in this way, multiple models for age inference have been constructed for the most commonly encountered forensic tissues (blood, oral mucosa, semen). The analysis of skeletal remains has also been attempted and prediction models for bone have now been reported. Recently, the VISAGE Enhanced Tool was developed for the simultaneous DNA methylation analysis of 8 age-correlated loci using targeted high-throughput sequencing. It has been shown that this method is compatible with epigenetic age estimation models for blood, buccal cells, and bone. Since when dealing with decomposed cadavers or postmortem samples, cartilage samples are also an important biological source, an age prediction model for cartilage has been generated in the present study based on methylation data collected using the VISAGE Enhanced Tool. In this way, we have developed a forensic cartilage age prediction model using a training set composed of 109 samples (19-74 age range) based on DNA methylation levels from three CpGs in FHL2, TRIM59 and KLF14, using multivariate quantile regression which provides a mean absolute error (MAE) of ± 4.41 years. An independent testing set composed of 72 samples (19-75 age range) was also analyzed and provided an MAE of ± 4.26 years. In addition, we demonstrate that the 8 VISAGE markers, comprising EDARADD, TRIM59, ELOVL2, MIR29B2CHG, PDE4C, ASPA, FHL2 and KLF14, can be used as tissue prediction markers which provide reliable blood, buccal cells, bone, and cartilage differentiation using a developed multinomial logistic regression model. A training set composed of 392 samples (n = 87 blood, n = 86 buccal cells, n = 110 bone and n = 109 cartilage) was used for building the model (correct classifications: 98.72%, sensitivity: 0.988, specificity: 0.996) and validation was performed using a testing set composed of 192 samples (n = 38 blood, n = 36 buccal cells, n = 46 bone and n = 72 cartilage) showing similar predictive success to the training set (correct classifications: 97.4%, sensitivity: 0.968, specificity: 0.991). By developing both a new cartilage age model and a tissue differentiation model, our study significantly expands the use of the VISAGE Enhanced Tool while increasing the amount of DNA methylation-based information obtained from a single sample and a single forensic laboratory analysis. Both models have been placed in the open-access Snipper forensic classification website.

DNA Purification from Bloodstains and Buccal Cells/Saliva on FTA® Cards.

FTA® cards enable efficient, long-term storage of blood and buccal cells/saliva samples for future forensic DNA analysis; these are typically collected as known reference samples, as opposed to evidentiary, crime scene samples. Upon contact with the FTA® card, cells are lysed and the DNA is immobilized. Different FTA® cards are available and have been specially formulated based on sample type: bloodstains are added to the traditional FTA® Card, while colorless sources (e.g., buccal cells/saliva) are added to the FTA® Indicating Card. The main difference between these cards is the presence of a pink dye embedded in the indicating cards that becomes white when exposed to colorless fluids, like saliva; this aids in location confirmation of the stain for future sampling. Although DNA can be eluted/extracted from FTA® punches using various methods or, alternatively, direct STR amplification from unpurified punches can be performed, the protocol herein describes a simple purification method for bloodstained punches from FTA® Cards as well as buccal/saliva-stained punches from FTA® Indicating Cards. Following this purification, STR amplification can be performed via the "punch-in" method.

Association of buccal micronucleus cytome assay (BMNCyt) biomarkers with inorganic element concentration and genetic polymorphisms in welders.

Welding fumes are classified as carcinogenic to humans. The aim of the present study was to measure buccal micronucleus cytome assay biomarkers and to evaluate their association with inorganic elements and genetic polymorphisms (XRCC1, OGG1, XRCC3, GSTM1, and GSTT1) in welders (n = 98) and control individuals (n = 100). Higher levels of DNA damage and cell death were observed in the exposed group. Also, a significant correlation between the frequency of micronuclei and Na, Si, Cl, Ti, Cr, Zn and Mg concentrations. The formation of micronuclei, binucleated cells, cell death was associated with polymorphisms in repair pathways. The OGG1Ser326Cys and XRCC3 241Thr/Met genotypes were associated with cell death. Individuals with GSTM1 null genotype had a higher frequency of micronuclei. These results demonstrate that the deleterious effects of exposure to welding fumes are exacerbated by lifestyle habits, and genetic polymorphisms can influence DNA damage and cell death.

Is telomere length in buccal or salivary cells a useful biomarker of exposure to air pollution? A review.

Telomeres are repetitive DNA-protein sequences located at the end of chromosomes and play an essential role in preserving information in our genome by protecting against end-to-end fusion, nucleolytic degradation, breakage, and inappropriate recombination. The telomeres shorten with aging and this process can be affected by oxidative stress and inflammation. Environmental and occupational factors may contribute to telomere length (TL) shortening, as demonstrated by an increasing number of studies. In particular, air pollution was associated with aging-related health outcomes and molecular alterations, such as telomeric shortening. Leukocytes are widely used for TL measurement. However, buccal and salivary cells have more intimate contact with airborne pollutants and are easier to sample. The objective of this review was to identify whether salivary or buccal TL represents a valid marker for evaluating the effects of pollution on health. The reviewed studies investigated the association between TL and occupational exposure (genotoxic substances in mechanical workers, and pesticides in pesticides applicators), residential traffic exposure (NOx, NO2, PM2.5, PM10, and black carbon), and household air pollution (PM2.5 and black carbon from biomass stoves). The studies involved adults and children. Although few studies have yet been carried out, almost all reported a negative association between salivary or buccal TL and exposure to air pollutants stating that it could be a good indicator of occupational or airborne pollution exposure. However, further research is needed to evaluate the effect of acute versus long-term exposure on salivary or buccal TL as well as the role of confounding factors. Moreover, most of the reviewed studies were conducted on healthy adults, so it is important to deeply investigate how TL is associated with all-cause mortality such as cancer, diabetes, cardiovascular disease, and respiratory disease, how it can be affected during childhood, and which changes over time can be associated with diseases' onset in adulthood.

Comparison of Telomere Length between Buccal Cells and Blood Cells.

Telomere length (TL) in blood cells is commonly used as a proxy for TL in other tissue types. The source of DNA of adequate quality and quantity is important for TL analysis. Compared to blood cells, buccal cells easy for genomic DNA preparation would facilitate the rapid and reliable TL analysis. However, the feasibility of buccal cells for TL analysis remains yet unestablished. We characterized TL of buccal cells and blood cells collected from 52 individuals using buccal cell swabs and fingertip sticks. Relative TL (RTL) determined by quantitative PCR showed that there is a strong correlation between buccal RTL and blood RTL (r=0.877, p<0.001), suggesting that buccal cells are adequate sources of DNA for TL analysis. The validity of sampling using buccal cell swabs provides simple operation and good reproducibility for TL analysis, that overcomes the discomfort and risk of infection caused by blood sampling.

Cellular Concentration of Survivin and Caspase 3 in Habitual Tobacco Chewers with and without Oral Squamous Cell Carcinoma in South Indian Rural Population-A Case Control Study.

Background: There is paucity of data on tissue levels of Survivin and Caspase 3 in south Indian tobacco chewers with oral Squamous cell carcinoma (OSCC). Oral cancer is a rapidly growing, highly prevalent head and neck malignancy; it involves a mucosal epithelium of a buccal cavity exposed to tobacco and other carcinogens. The basis of the survival of a tumor cell or transformed normal cell into a neoplastic cell is by the suppression of apoptosis regulation. Recently, researchers have focused on Survivin, an inhibitor of apoptosis family of proteins (IAP), involved in apoptosis regulation in cancer cells targeting the executioner Caspase 3. The current study aims to quantify the cellular levels of Survivin and Caspase 3 in tobacco chewers with OSCC and in habitual tobacco chewers without OSCC, in comparison to controls. Methods: A single centric case control study included 186 study subjects, categorized into: Group I (n = 63), habitual tobacco chewers with OSCC; Group 2 (n = 63), habitual tobacco chewers without OSCC; and Group 3 (n = 63), the controls. Resected tumor tissue from Group 1 and buccal cell samples from Groups 2 and 3 were collected into phosphate buffer saline (PBS) and assayed for Survivin and Caspase 3 levels by the ELISA sandwich method. Results: The mean ± SD of the Survivin protein in Group 1 was (1670.9 ± 796.21 pg/mL); in Group 2, it was (1096.02 ± 346.17 pg/mL); and in Group 3, it was (397.5 ± 96.1 pg/mL) with a significance of p < 0.001. Similarly, the level of Caspase 3 in Group 1 was (7.48 ± 2.67 ng/mL); in Group 2, it was (8.85 ± 2.41 ng/mL); and in Group 3, it was (2.27 ± 2.24 ng/mL) with a significance of p < 0.001. Conclusion: The progressive transformation of buccal cells to neoplastic cells is evident; in the case of OSCC, this indicates that the over-expression of Survivin compared to Caspase 3 confirms the suppression and dysregulation of apoptosis.

Epigenetic age estimation in saliva and in buccal cells.

Age estimation based on epigenetic markers is a DNA intelligence tool with the potential to provide relevant information for criminal investigations, as well as to improve the inference of age-dependent physical characteristics such as male pattern baldness or hair color. Age prediction models have been developed based on different tissues, including saliva and buccal cells, which show different methylation patterns as they are composed of different cell populations. On many occasions in a criminal investigation, the origin of a sample or the proportion of tissues is not known with certainty, for example the provenance of cigarette butts, so use of combined models can provide lower prediction errors. In the present study, two tissue-specific and seven age-correlated CpG sites were selected from publicly available data from the Illumina HumanMethylation 450 BeadChip and bibliographic searches, to help build a tissue-dependent, and an age-prediction model, respectively. For the development of both models, a total of 184 samples (N = 91 saliva and N = 93 buccal cells) ranging from 21 to 86 years old were used. Validation of the models was performed using either k-fold cross-validation and an additional set of 184 samples (N = 93 saliva and N = 91 buccal cells, 21-86 years old). The tissue prediction model was developed using two CpG sites (HUNK and RUNX1) based on logistic regression that produced a correct classification rate for saliva and buccal swab samples of 88.59 % for the training set, and 83.69 % for the testing set. Despite these high success rates, a combined age prediction model was developed covering both saliva and buccal cells, using seven CpG sites (cg10501210, LHFPL4, ELOVL2, PDE4C, HOXC4, OTUD7A and EDARADD) based on multivariate quantile regression giving a median absolute error (MAE): ± 3.54 years and a correct classification rate ( %CP±PI) of 76.08 % for the training set, and an MAE of ± 3.66 years and a %CP±PI of 71.19 % for the testing set. The addition of tissue-of origin as a co-variate to the model was assessed, but no improvement was detected in age predictions. Finally, considering the limitations usually faced by forensic DNA analyses, the robustness of the model and the minimum recommended amount of input DNA for bisulfite conversion were evaluated, considering up to 10 ng of genomic DNA for reproducible results. The final multivariate quantile regression age predictor based on the models we developed has been placed in the open-access Snipper forensic classification website.

ß2-microglobulin is overexpressed in buccal cells of elderly and correlated with expression of p16 and inflammatory genes.

ß2M (Beta 2 microglobulin) is a small protein that is found in all nucleated cells, previous finding showed that its levels increased in the serum of the elderly. Buccal cell samples are none invasive approach for assessing the expression of target genes. There was rationality to assess the expression of ß2M in buccal cells of people of a different group of ages. Indeed, the expression of ß2M increased significantly with fold change 3.40, 4.80, 6.60**, 8.20*** and 12.04*** for the group of age 18-25 years, 26-35 years, 36-45 years, 46-55 years, and 56-70 years respectively. The same observation was seen with markers of biological aging (p16INK4a) with fold change 3.19, 3.90, 4.80*, 8.50*** and 12.40*** for the group of age 18-25 years, 26-35 years, 36-45 years, 46-55 years, and 56-70 years respectively. As expected, there was an increase in the inflammatory genes (IL-1 ß and IL-6) expression in the elderly. Moreover, there was a direct significant correlation (r = 90, p < 0.001) between ß2M expression and age (years), and the same direct significant correlation between p16INK4a expression and age (years) was also seen (r = 90, p < 0.001). In addition, a direct correlation between ß2M and p16INK4a was also seen (r = 0.8.3, p < 0.001), there was also direct correlation between ß2M and IL-1 ß and IL-6 with (r = 0.5, p < 0.001; r = 0.68, p < 0.001) respectively. This evidence showed that ß2M increased in buccal cells of the elderly compared to younger, and thereby buccal cells can be exploited to assess biological aging by measuring ß2M levels, however, large sample size and using another assessing method such as ß2M protein levels should be performed to confirm the results.

Rapid and inexpensive method of PCR ready DNA isolation from human peripheral blood and saliva.

BACKGROUND: The isolation of nucleic acids is a frequently performed procedure in the molecular biology area. Although several rapid DNA isolation techniques from human peripheral blood and saliva have been developed, there are still some disadvantages - volume, time, cost, and yield are a few notable ones. OBJECTIVE: We aim to develop a rapid and inexpensive method to isolate high-molecular-weight genomic DNA from human peripheral blood and saliva that can be used for molecular biology experiments. METHODS: Five DNA isolation methods with slightly varying protocols were used. High-quality DNA obtained from one specific method was further amplified by PCR and the template with good amplification was further used for performing RFLP and sequencing. RESULTS: Out of 5 different isolation methods (R1 to R5), DNA obtained from the R4 was of good quality (molecular weight is > 10 kb and 260/280 ratio is 1.89 ± 0.2), which allows successful PCR amplification and good separation in Restriction Fragment Length Polymorphism analysis. Sequencing by the Sanger Sequencing produced a good readable sequence of an amplified fragment from Method R4 DNA. CONCLUSION: In the present study we have developed a simple, rapid, and cost-effective DNA isolation method, which uses low sample volume and yields good quantity and high-quality product. The DNA obtained is highly fit for molecular genetics research applications.

Cytogenetic Biomonitoring in Buccal Mucosa Cells from Seaport Dockers.

BACKGROUND/AIM: Dockers of seaport working as stevedores are self-employed workers who carry out arduous and dangerous activities. To date, few studies have investigated the human health risks in these professionals. The aim of this study was to evaluate cytogenetic damage in oral cells of dockers of seaports working as stevedores by micronucleus assay in buccal cells. PATIENTS AND METHODS: For this study, a total of 26 seaport dockers working as stevedores aged 51.2±8.4 years (all men) were included in this study. All volunteers had worked for at least 3 years. The control group consisted of 25 participants aged 55.2±9.9 years (all men), who did not work in the Port of Santos city. RESULTS: The results showed statistically significant differences (p<0.05) of micronucleated cells in buccal mucosa cells of seaport dockers. Pyknosis, karyolysis and karrhyorexis did not show statistically significant differences (p>0.05) between groups. CONCLUSION: The results of the present study suggest that seaport dockers present mutagenicity in oral cells.

Cytotoxicity, oxidative stress, and inflammatory response of smokeless tobacco extracts and cytotoxicity of combustible cigarette whole smoke in a 3D oral organotypic buccal cell model.

Oral disease is frequently associated with viral and environmental exposures and oral hygiene. The use of tobacco is a risk factor in the development of oral disease. Cytotoxicity, inflammatory response, and oxidative stress have been reported to have a role in the development of oral disease. These three endpoints were evaluated in a 3D human oral buccal model, EpiOral™, following exposure to CORESTA reference smokeless tobacco products (CRPs) and cigarette whole smoke. CRPs for Swedish style snus (CRP1), moist snuff (CRP2), and dry snuff (CRP3) were each extracted in complete artificial saliva (CAS) with a ratio of 300 mg CRP to 1 mL of CAS. Each of the CRP extracts (15-300 mg/ml) were applied to the apical side of a 3D organotypic buccal cell model for 24 or 48 h continuously, then cytotoxicity (LDH), oxidative stress (8-isoprostane), and inflammatory response (IP10, IL-1α, and IL-8) were measured. Experiments with 3R4F cigarettes were conducted by exposing the buccal tissues to whole smoke for a maximum of 2.5 h. Cytotoxicity (MTT) was measured 24 h post-exposure. Exposure of buccal tissues to whole smoke from a cigarette induced a dose-dependent cytotoxic response. In contrast, the CRP extracts elicited minimal cytotoxicity (<15%) when compared to CAS (vehicle control), but time- and dose-dependent effects on oxidative stress and inflammatory response were observed. Collectively, these data demonstrate that a 3D organotypic buccal human model may be used to assess biological mechanisms (MOAs) involved in the development of oral disease following exposure to smokeless tobacco products and may be applicable for differentiation between tobacco product categories.

Histopathological Features and Protein Markers of Arrhythmogenic Cardiomyopathy.

Arrhythmogenic cardiomyopathy (ACM) is a heritable heart muscle disease characterized by syncope, palpitations, ventricular arrhythmias and sudden cardiac death (SCD) especially in young individuals. It is estimated to affect 1:5,000 individuals in the general population, with >60% of patients bearing one or more mutations in genes coding for desmosomal proteins. Desmosomes are intercellular adhesion junctions, which in cardiac myocytes reside within the intercalated disks (IDs), the areas of mechanical and electrical cell-cell coupling. Histologically, ACM is characterized by fibrofatty replacement of cardiac myocytes predominantly in the right ventricular free wall though left ventricular and biventricular forms have also been described. The disease is characterized by age-related progression, vast phenotypic manifestation and incomplete penetrance, making proband diagnosis and risk stratification of family members particularly challenging. Key protein redistribution at the IDs may represent a specific diagnostic marker but its applicability is still limited by the need for a myocardial sample. Specific markers of ACM in surrogate tissues, such as the blood and the buccal epithelium, may represent a non-invasive, safe and inexpensive alternative for diagnosis and cascade screening. In this review, we shall cover the most relevant biomarkers so far reported and discuss their potential impact on the diagnosis, prognosis and management of ACM.

Cytogenetic Biomonitoring in Buccal Mucosa Cells of COVID-19 Patients: Preliminary Findings.

BACKGROUND/AIM: COVID-19 may lead to progressive respiratory failure as a consequence of alveolar damage, resulting in death. The aim of this study was to evaluate cytogenetic damage in oral cells of COVID-19 patients by micronucleus assay. PATIENTS AND METHODS: A total of 11 COVID-19 patients aged 40.7±9.3 years (5 men and 6 women) were included in this study. For the control group, a total of 15 participants not infected with SARS-CoV-2 virus were included. The mean age was 41.6±6.2 years (5 men and 10 women). RESULTS: The results showed statistically significant differences (p<0.05) in micronucleated buccal mucosa cells of COVID-19 patients. In addittion, a statistically significant increase in karyolysis and karrhyorexis (p<0.05) was observed in COVID-19 patients compared to control. CONCLUSION: SARS-CoV-2 virus can induce mutagenesis and cytotoxicity in oral cells.

Effect of Angiotensin-I Converting Enzyme Gene Insertion/Deletion Polymorphism on genome instability in children living in Russian Arctic.

Main risks of arterial hypertension manifest in childhood. Children living in the Far North are especially susceptible to this. There is a need for an inexpensive, non-invasive and simple diagnosis of the risk of childhood pathologies. It was previously found that the genotype DD of the in/del polymorphic marker of the ACE gene is found in people at risk of developing cardiovascular pathologies. Buccal micronucleus cytome assay and genetic analysis were used in the work. In total, 77 schoolchildren from the city of Apatity, aged 15-17 years old, were examined. We have shown that carriers of the D allele have a tendency to an increase in the frequency of cells with micronuclei. In the case of homozygous I/I variant, the frequency of occurrence of cells with karyopycnosis is significantly higher than in carriers of allele D. Polymorphic marker in/del of the ACE gene is associated with apoptotic changes in the cells of the studied children. The in/del polymorphic marker of the ACE gene can be used as a prognostic marker of the processes of genome destabilization at the early stages of development of the human body.

Genotoxic Activity of Particulate Matter and In Vivo Tests in Children Exposed to Air Pollution.

The aim of this paper was to investigate the relationship between micronuclei and DNA damage in children's buccal mucosa cells and the genotoxicity and mutagenicity of the different sized fractions of particulate matter as well as the concentration of PAHs (polycyclic aromatic hydrocarbons) and metals in particulate matter. Air particulate matter was collected by high volume samplers located near the schools attended by the children on the same days of biological samplings. The mutagenic activity was assessed in different cells in in vitro tests (Ames test on bacteria and comet test on leukocytes). Our study showed weak positive correlations between (a) the mutagenicity of the PM0.5 fraction and PAHs and (b) the micronuclei test of children's buccal cells and PAHs detected in PM0.5 and PM0.5-3 fractions. A positive correlation was also found between in vitro comet test on leukocytes and PAHs in the PM3-10 fraction. No correlation was observed for metal concentrations in each PM fraction.

Development of the VISAGE enhanced tool and statistical models for epigenetic age estimation in blood, buccal cells and bones.

DNA methylation is known as a biomarker for age with applications in forensics. Here we describe the VISAGE (VISible Attributes through GEnomics) Consortium's enhanced tool for epigenetic age estimation in somatic tissues. The tool is based on eight DNA methylation markers (44 CpGs), bisulfite multiplex PCR followed by sequencing on the MiSeq FGx platform, and three statistical prediction models for blood, buccal cells and bones. The model for blood is based on six CpGs from ELOVL2, MIR29B2CHG, KLF14, FHL2, TRIM59 and PDE4C, and predicts age with a mean absolute error (MAE) of 3.2 years, while the model for buccal cells includes five CpGs from PDE4C, MIR29B2CHG, ELOVL2, KLF14 and EDARADD and predicts age with MAE of 3.7 years, and the model for bones has six CpGs from ELOVL2, KLF14, PDE4C and ASPA and predicts age with MAE of 3.4 years. The VISAGE enhanced tool for age estimation in somatic tissues enables reliable collection of DNA methylation data from small amounts of DNA using a sensitive multiplex MPS assay that provides accurate estimation of age in blood, buccal swabs, and bones using the statistical model tailored to each tissue.