Percentage Of DNA In Tail Research Articles

The effects of anabolic-androgenic steroids on DNA damage in bodybuilders’ blood lymphocytes

Background Nowadays bodybuilders use anabolic steroids frequently. Abuse of these substances can cause significant side effects; therefore, we aim to investigate the effect of anabolic steroids on DNA damage in bodybuilders’ blood lymphocytes. Methods and materials This case-control study was performed on 36 male bodybuilders in Gonabad. The case group included bodybuilders with a history of taking anabolic-androgenic steroids (n = 18), and the control group composed of bodybuilders who did not use anabolic-androgenic steroids (n = 18). Intravenous blood samples were obtained and then the lymphocytes, cells and electrophoresis of blood were extracted. Afterward, the coloured slides and DNA damage were measured using a fluorescent microscope and CometScore software. The DNA damage was compared using t-tests . Results Results showed that there was no significant difference between age, marital status, BMI, systolic and diastolic blood pressure in the case and control group. However, parameters related to the DNA damage including tail length, percent tail DNA, and tail moment were significantly higher in the case group. Conclusion The use of anabolic-androgenic steroids increases DNA damage in the bodybuilders’ blood lymphocytes.

Characteristics, Yield, Flow Cytometer, DNA Fragmentation, and Comet Assay Parameters of Goat Spermatozoa in Semen of Zaraibi and Baladi Bucks at Young and Old Ages

The aim of this study was to determine goat breed (Zaraibi and Baladi) or buck age (young and old) effect on characteristics, production, flow cytometer, DNA fragmentation and comet assay parameters of spermatozoa. Twelve Baladi (BG) and Zaraibi (ZG) bucks, 3 old (2-4 years) and 3 young (8-12 months) from BG or ZG used for semen collection for 24 weeks. Volume (EV), sperm progressive motility (PM), livability (LS), abnormality (SA), and concentration (SCC) were evaluated, sperm outputs (SO) were calculated. Sperm apoptosis, DNA fragmentation and comet assay were analyzed. Results revealed that PM, LS, SA, SCC, total, motile, live, normal, and functional SO per ejaculate were significantly higher in ZG than BG and in old than young bucks in each breed. Both EV and LS were significantly higher, while SCC was significantly lower in old than young ZG. Each of EV, PM, and SCC was significantly higher, while SA was significantly lower in old than young BG. Viable sperm, haploid and cell cycle percent was significantly higher, while early apoptotic, apoptotic, and necrotic spermatozoa percent was significantly lower in old than young bucks of each breed. Spermatid percent in ZG and diploid percent in BG were significantly higher in old than young bucks. Tailed sperm, tail length, tail DNA percentage, and tail moment were significantly lower in ZG than BG, and in old than young bucks of each breed. It can be stated that Zaraibi bucks has a good potential for semen production than Baladi breed.

Antioxidant and antigenotoxic potential of Morinda tinctoria Roxb. leaf extract succeeding cadmium exposure in Asian catfish, Pangasius sutchi

The present study investigated the protective effect of methanolic leaf extract of Morinda tinctoria. Roxb (MEMT) (200 mg/kg) via feed in supplementation with standard compound silymarin (400 mg/kg). M. tinctoria (Roxb.) belonging to Rubiaceae, is an evergreen shrub indigenous to unfarmed lands of tropical countries. It is considered as an essential traditional medicine attributing for the potential antioxidant and anti-inflammatory properties. The enhancements of antioxidant and antigenotoxic status in different tissues of cadmium (Cd) intoxicated Pangasius sutchi were evaluated by using various antioxidant assays (superoxide dismutase (SOD) and catalase (CAT) and lipid peroxidation) in addition to micronuclei (MN), binuclei (BN) and comet assay. The cadmium toxicated fish showed a significant (p < 0.001) increase in lipid peroxidation (LPO) activities in liver, gills, muscle and kidney whereas significant (p < 0.001) decline were observed in superoxide dismutase (SOD) and catalase (CAT) contents in all fish tissues. The results also revealed that, Cd exposure induced the formation of genotoxic endpoints like MN, BN, notched nuclei, kidney shaped nuclei and DNA damage in the fish erythrocytes. Maximum of 26.8% MN frequencies and maximum of 66.74% tail DNA damage were observed on the 7th day of Cd exposure. A time-dependent significant increase (p < 0.001) in the frequencies of MN, BN and tail DNA damage were observed in all treated groups against the control which started to decline from 14th day onwards. There was a decline in the LPO content, frequencies of MN, BN and percentage of tail DNA in contrast to significant elevation in SOD and CAT content in all tissues due to the combined treatment of M. tinctoria feed and water borne Cd exposure. It can be concluded from our observations that, supplementation of M. tinctoria leaf extract through feed alone produced enhanced antioxidant and antigenotoxic status in cadmium treated fish by diminishing oxidative stress and genotoxicity effects in a time dependent manner.

Genomic markers for the biological responses of Triclosan stressed hatchlings of Labeo rohita.

Triclosan (TCS) used commonly in pharmaceuticals and personal care products has become the most common pollutant in water. Three-day-old hatchlings of an indigenous fish, Labeo rohita, were given 96h exposure to a nonlethal (60 μg L-1) and two moderately lethal concentrations (67 and 97 μg L-1) of TCS and kept for 10 days of recovery for recording transcriptomic alterations in antioxidant/detoxification (SOD, GST, CAT, GPx, GR, CYP1a and CYP3a), metabolic (LDH, ALT and AST) and neurological (AchE) genes and DNA damage. The data were subjected to principal component analysis (PCA) for obtaining biomarkers for the toxicity of TCS. Hatchlings were highly sensitive to TCS (96h LC50 = 126 μg L-1 and risk quotient = 40.95), 96h exposure caused significant induction of CYP3a, AChE and ALT but suppression of all other genes. However, expression of all the genes increased significantly (except for a significant decline in ALT) after recovery. Concentration-dependent increase was also observed in DNA damage [Tail Length (TL), Tail Moment (TM), Olive Tail Moment (OTM) and Percent Tail DNA (TDNA)] after 96 h. The damage declined significantly over 96h values at 60 and 67 μg L-1 after recovery, but was still several times more than control. TCS elicited genomic alterations resulted in 5-11% mortality of exposed hatchlings during the recovery period. It is evident that hatchlings of L. rohita are a potential model and PCA shows that OTM, TL, TM, TDNA, SOD and GR (association with PC1 during exposure and recovery) are the biomarkers for the toxicity of TCS. Graphical abstract.

Abstract 2350: xCT overexpression induces metabolic reprogramming, epigenetic alterations, and DNA damage in precancerous airway epithelial cells

Abstract Metabolic reprogramming and genomic instability are two hallmarks of cancer known to drive tumorigenesis. While each has been investigated individually, there is a growing interest in their interplay during early cancer development. High expression of the cystine/glutamate antiporter SLC7A11 (xCT) is frequently observed in lung cancer. Our laboratory previously demonstrated that overexpressing xCT in normal bronchial airway epithelial cells induced metabolic reprogramming and caused cells to display precancerous properties, such as increased proliferation and colony formation in soft agar. In this study, we further investigated the effects of xCT overexpression in the airway epithelium with the goal of elucidating the role of xCT in influencing cancer-driving hallmarks and the interplay of these hallmarks during early tumorigenesis. We hypothesized that xCT overexpression-induced metabolic reprogramming leads to epigenetic changes through the perturbation of epigenetic-related metabolite levels. Furthermore, we posited that this altered epigenome changes the expression levels of key genes involved in genome stability maintenance, ultimately inducing genomic instability. Utilizing a LC-MS/MS-based metabolomic analysis, we observed significantly altered levels of 224 different metabolites in our xCT overexpressing cells, including metabolites involved in epigenetic processes such as S-adenosylhomocysteine and acetyl-CoA. We found that xCT overexpression alters several global histone modifications, increasing H3K9me3 and H3K9ac by 3.2 (P = 0.02) and 3.9-fold (P = 0.02) respectively. We also showed that xCT overexpression increased global DNA methylation by 56% (P = 0.04). Additionally, RNA-seq revealed significant alterations (logFC&amp;gt;2 or &amp;lt;0.5, pAdj&amp;lt;0.05) in the expression of over 100 genes, including a significant decrease in the expression of certain tumor suppressor genes such as TRIM29, and a significant increase in the expression of certain proto-oncogenes, such as CCND1. Finally, we discovered that xCT overexpression induces DNA damage, increasing the percentage of damaged DNA in comet tails in a comet assay by 15.1% (P = 0.002). Taken together, xCT overexpression in normal bronchial airway epithelial cells induces metabolic reprogramming, alters the epigenetic landscape and gene expression, and causes higher levels of DNA damage. Future experiments elucidating causal links between these processes, including ChIP-seq and WGBS are underway. This study provides a promising foundation for the connections between xCT-induced metabolic reprogramming, epigenetic alterations, and genomic instability, an imperative step in elucidating an effective, potentially multifaceted approach to preventing lung cancer development. Citation Format: Dalton Hill, Jamshedur Rahman, Christien Kluwe, Jamey Young, Emily Hodges, Pierre P. Massion. xCT overexpression induces metabolic reprogramming, epigenetic alterations, and DNA damage in precancerous airway epithelial cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2350.

Association of DNA damage with vitamin D and hair heavy metals of obese women

BackgroundObesity has been linked to DNA damage. The modifiable risk factors may modulate the impact of obesity on DNA damage.ObjectiveThis study aimed to assess DNA damage and its association with dietary nutrient, serum 25-hydroxyvitamin D (25(OH)D) and concentration of hair heavy metals of obese and non-obese women.MethodA case–control study was conducted involving 134 women aged between 20 and 50 years. Serum 25(OH)D, fasting glucose, and lipid profile were assessed. Indicators of DNA damage such as percentage of tail DNA, tail moment, tail olive moment, tail intensity and tail length were measured using an alkaline-comet assay. Concentrations of hair heavy metals were quantified using inductively coupled plasma–mass spectrometry (ICP–MS). Participants' daily energy, macro, and micronutrient intake were collected using the Food Frequency Questionnaire.ResultsMean values of serum 25(OH)D was 31.8 ± 0.9 nmol/L. 96.3% of participants were vitamin D deficiency (< 50 nmol/L). The mean BMI was 26.3 ± 0.5 kg/m2. Half of the participants (50.7%) have a high frequency of DNA strand breaks. Mean concentration of hair heavy metals (mg/kg) were 0.1 ± 0.03 (arsenic), 0.2 ± 0.1 (cadmium), 1.0 ± 0.4 (mercury), 2.8 ± 0.8 (lead),and 6.2 ± 0.4 (chromium). There was no significant difference for the mean of serum 25(OH)D, indicators of DNA damage, concentrations of hair heavy metals and dietary nutrients between obese and non-obese groups (p > 0.05). Obese women with serum 25(OH)D level of ≥ 31 nmol/L had a significantly lower tail moment (p = 0.029) and tail olive moment (p = 0.031); thus, indicating less DNA damage. Additionally, obese women with hair chromium concentration of ≥ 5.88 mg/kg had a significantly higher tail moment (p = 0.047), indicating more DNA damage.ConclusionDNA damage among obese women correlated with serum 25(OH)D and hair chromium.

Complete Chromatin Decondensation of Pig Sperm Is Required to Analyze Sperm DNA Breaks With the Comet Assay.

Sperm quality is usually evaluated prior to artificial insemination in farm animals. In addition to conventional semen analysis, other biomarkers, such as mitochondrial activity, integrity and lipid disorder of plasma membrane, generation of reactive oxygen species (ROS) and sperm DNA integrity, have been found to be related to fertility rates in different species. While mounting evidence indicates that the Comet assay is a sensitive method for the detection of DNA breaks, complete sperm chromatin decondensation is required in order to properly analyze the presence of single- and double-strand DNA breaks. In this sense, a previous study showed that longer lysis treatment with proteinase K is needed to achieve complete chromatin decondensation. The current work sought to determine which specific lysis treatment leads to complete chromatin decondensation in pig sperm, as this is needed for the measurement of DNA damage in this species. With this purpose, incubation with a lysis solution containing proteinase K for 0, 30, and 180 min was added to the conventional protocol. The impact of the DNA damage induced by hydrogen peroxide (H2O2; 0.01 and 0.1%) and DNAse I (1U and 4U) was also evaluated. Complete chromatin decondensation was only achieved when a long additional lysis treatment (180 min) was included. Furthermore, olive tail moment (OTM) and percentage of tail DNA (TD) indicated that a higher amount of DNA breaks was detected when hydrogen peroxide and DNAse I treatments were applied (P < 0.05). The comparison of treated and control sperm allowed defining the thresholds for OTM; these thresholds revealed that the percentage of sperm with fragmented DNA determined by the alkaline Comet does not depend on chromatin decondensation (P > 0.05). In conclusion, complete chromatin decondensation prior to alkaline and neutral Comet assays is needed to analyze DNA breaks in pig sperm.

Physico-Chemical Properties and Biocompatibility of Thermosensitive Chitosan Lactate and Chitosan Chloride Hydrogels Developed for Tissue Engineering Application.

Recently, the modification of the initial structure of biopolymers, mainly chitosan, has been gaining importance with a view to obtain functional forms with increased practicality and specific properties enabling their use in tissue engineering. Therefore, in this article, the properties (structural and biological) of thermosensitive hydrogels obtained from chitosan lactate/chloride and two types of crosslinking agents (β-glycerol phosphate disodium salt pentahydrate and uridine 5′-monophosphate disodium salt) are discussed. The aim of the research is to identify changes in the structure of the biomaterials during conditioning in water. Structural investigations were carried out by FTIR spectroscopy. The crystallinity of gels was determined by X-ray diffraction analysis. The biocompatibility (evaluation of cytotoxicity and genotoxicity) of chitosan hydrogels was investigated by contact with human colon adenocarcinoma cell line for 48 h. The cytotoxicity was verified based on the colorimetric resazurin assay, and the genotoxicity was checked by the comet assay (percentage of DNA in the comet tail). The conducted research showed that the analyzed types of chitosan hydrogels are non-cytotoxic and non-genotoxic materials. The good biocompatibility of chitosan hydrogels surfaces makes them interesting scaffolds with clinical potential in tissue regeneration engineering.

Hypothyroidism induces oxidative stress and DNA damage in breast.

Breast cancer and thyroid dysfunctions have been associated for decades. Although many studies suggest a biological correlation, the mechanisms linking these two pathologies have not been elucidated. Reactive oxygen species (ROS) can oxidize lipids, proteins, and DNA molecules and may promote tumor initiation. Hence, we aimed at evaluating the mammary redox balance and genomic instability in a model of experimental hypothyroidism. Female Wistar rats were treated with 0.03% methimazole for 7 or 21 days to evaluate ROS generation, antioxidant enzyme activities, and oxidative stress biomarkers, as well as genomic instability. After 7 days, lower catalase, GPX, and DUOX activities were detected in the breast of hypothyroid group compared to the control while the levels of 4-hydroxynonenal (HNE) were higher. In addition, hypothyroid group showed an increase in γH2Ax/H2Ax ratio. Twenty-one days hypothyroid group had increased catalase and SOD activities, without significant differences between groups in the levels of oxidative stress biomarkers and DNA damage. TSH-treated MCF10A cells showed a higher extracellular, intracellular, and mitochondrial ROS production. Additionally, greater DNA damage was observed in these cells, demonstrated by a higher comet tail DNA percentage and increased 53BP1 foci. Finally, we found that TSH treatment was not able to alter cell viability. The Genome Cancer Atlas (TGCA) data showed that high TSHR expression is associated with more invasive breast cancer types. In conclusion, we demonstrate that oxidative stress and DNA damage in breast are early events of experimental hypothyroidism. Moreover, high TSH levels induce oxidative stress and genomic instability in mammary cells.

Evidence-based meta-analysis of the genotoxicity induced by microplastics in aquatic organisms at environmentally relevant concentrations

Microplastics (MPs) attract global concern due to their ubiquitous existence in aquatic environments. However, the genotoxic effect of MPs on aquatic organisms in the natural environment remains controversial. Therefore, this meta-analysis was conducted by recompiling 44 individual studies from 12 publications to determine whether MPs could induce genotoxicity in aquatic organisms at environmentally relevant concentrations (≤1 mg/L, median = 0.5 mg/L). Multiple genotoxic endpoints were involved, including the percentage of DNA in tail (TDNA%), tail length (TL), olive tail moment (OTM), and the number of micronuclei (NM), and their increases represented the biologically adverse effects (i.e. genotoxicity). The results showed that all included endpoints tended to increase after exposure to MPs, among which TDNA%, TL and NM were significantly increased by 20%, 32% and 81% compared with the control group, respectively. The overall estimate of all endpoints in the MPs-treated groups was remarkably increased by 24%, with high statistical power and no obvious publication bias, suggesting the evident genotoxicity caused by MPs. In addition, the magnitudes of MPs-induced genotoxicity were independent of selected endpoint, MP composition, morphology, exposure concentration and duration, but closely correlated with particle size, living habitat and tested species. Overall, this work provided a reference for the health risk assessment of MPs in the natural environment, contributing to our understanding the action mode of MPs at environmentally relevant concentrations.

Investigation of biological accumulation and eco-genotoxicity of bismuth oxide nanoparticle in fresh water snail Lymnaea luteola

Bismuth is one of the significant heavy metals widely used in agricultural industry. Freshwater snails are sentinel organism models for aquatic ecosystem pollution. In the present study, we designed to understand the mechanism of bismuth oxide nanoparticle (Bi2O3NPs) toxicity on Lymnaea luteola (L. luteola) by using different biomarkers. The LC50 – 96 h of Bi2O3NPs was found 72.6 µg/ml for L. luteola and based on LC50 – 96 h of Bi2O3NPs three concentrations sub lethal I ~ 18.15 µg/ml, sub lethal II ~ 36.30 µg/ml, and sub lethal III ~ 48.4 µg/ml were selected for further study. The snails were exposed to above sub lethal concentrations of NPs for 7 days and specimens were harvested at 1, 3 and 7 days for assessment oxidative stress, apoptosis and eco genotoxicity. In general, Bi2O3NPs showed significant (p 0.05, 0.01) ecotoxic effect on snails in both concentrations and time of exposure. The generation ROS were maximum at sublethal III at day 7. After exposure to sublethal concentrations of Bi2O3NPs for day 1, 3 and 7 significantly elevated malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione S-transferase (GST) levels with simultaneous decline in glutathione (GSH) in pancreatic gland tissues of treated snails. Moreover, Bi2O3NPs elicited a significant percentage of apoptotic/necrotic heamocyte cells hemolymph of exposed snails. A parallel tendency was seen for the fragmentation of DNA as determined in terms of the percentage of tail DNA and olive tail moment in pancreatic gland tissue of exposed snails. This study highlights the toxic perturbation of Bi2O3NPs in water bodies and may be useful to monitor the application and disposal of NPs.

Effect of diluent variation on cryopreservation of large yellow croaker Larimichthys crocea

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), survival rate, and DNA damage. Different types of CPAs, such as dimethyl sulfoxide (DMSO), propylene glycol (PG), ethylene glycol (EG), methanol, and glycerol, were tested for sperm preservation. The highest motility, SAI, and survival rate were observed when EG was used. Different diluents such as Stein’s solution, Hank’s balanced salt solution, marine fish Ringer’s solution, artificial seminal plasma (ASP) of small yellow croaker, and Cortland solution were investigated. The highest post-thaw motility was observed upon using ASP as the diluent. Different concentrations of EG were then mixed with ASP to identify the optimal EG concentration. Experimental results showed that the motility (70.33 ± 1.20%), SAI (5), and survival rate (78.30 ± 0.42%) of post-thaw sperm were optimum when 10% EG and ASP were used as the CPA and diluent of cryopreservation, respectively. Post-thaw sperm motility was high at equilibration times below 150 s and at an optimum dilution ratio of 1:1 (sperm: CPA + diluent) and was not significantly different compared with fresh sperm motility. The freezing rate was found to be slow below −10°C/min. The thawing temperature of 45°C was identified as ideal. The percentage of tail DNA in post-thaw sperm at 10% EG and ASP was also investigated and was found to have more significant DNA damage than that in fresh sperm but significantly lower damage than that in post-thaw sperm at EG concentrations of 5%, 15%, and 20% (p &lt; 0.05). The cryopreservation protocols obtained in this study will be useful in large yellow croaker hatcheries.

Antitumor impact of iron oxide nanoparticles in Ehrlich carcinoma-bearing mice

ABSTRACT Magnetic nanoparticles are promising approaches for cancer treatment. Iron oxide nanoparticles have been pre-formed by the co-precipitation method to investigate their antitumor activity on Ehrlich carcinoma in mice. The nanoparticles have been studied by UV spectrophotometer, transmission electron microscopy, dynamic light scattering, and zeta potential measurement. To determine the therapeutic impact of Iron oxide nanoparticles in tumor-bearing mice, in vivo experiments were carried out. Fourier Transform Infra-red (FTIR) spectroscopy and DNA comet assay were used to estimate the toxicity of nanoparticles of iron oxide. The tissue was analyzed using FTIR spectral parameters such as the area beneath the peak, peak position, and peak intensity. The results showed that iron oxide nanoparticles significantly led to antitumor activity against Ehrlich carcinoma. There was a low shift in position and intensity at the amide I band (1650 cm−1) in tissues of mice treated with iron oxide nanoparticles compared to the control group. Comet examination showed a decrease across all the parameters of the assay (tail moment, tail DNA percentage, and tail length) in the tumor + iron nanoparticles group, having values lower than the tumor group. According to the presented results, Iron oxide nanoparticles have exhibited therapeutic efficacy against cancer.

Evaluation of Cyto-genotoxicity of Perfluorooctane Sulfonate (PFOS) to Allium cepa.

Per- and polyfluoroalkyl substances (PFAS) have emerged as contaminants of global concern. Among several PFAS, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are persistent and bioaccumulative compounds. We investigated the cyto-genotoxic potential of PFOS to Allium cepa root meristem cells. The A. cepa root tips were exposed to 6 different concentrations (1-100 mg L-1 ) of PFOS for 48 h. Reduction in mitotic index and chromosomal aberrations was measured as genotoxic endpoints in meristematic root cells. Exposure to PFOS significantly affected cell division by reducing the miotic index at higher concentrations (>10 mg L-1 ). The median effect concentration of PFOS to elicit cytotoxicity based on the mitotic index was 43.2 mg L-1 . Exposure to PFOS significantly increased chromosomal aberrations at concentrations >25 mg L-1 . The common aberrations were micronuclei, vagrant cells, and multipolar anaphase. The alkaline comet assay revealed a genotoxic potential of PFOS with increased tail DNA percentage at concentrations >25 mg L-1 . To our knowledge, this is the first study to report the cyto-genotoxic potential of PFOS in higher plants. Environ Toxicol Chem 2021;40:792-798. © 2020 SETAC.

Abstract PO-001: xCT expression alters the epigenome and induces genomic instability

Abstract Metabolic reprogramming, remodeling of the epigenetic landscape, and genomic instability are three processes that drive tumorigenesis. While each has been investigated individually, there is a growing interest in the interplay between each process during early cancer development. High expression of the cystine/glutamate antiporter SLC7A11 (xCT) is frequently seen in lung cancer. Our lab previously demonstrated overexpression of xCT in normal bronchial airway epithelial cells is sufficient to induce metabolic reprogramming. In this study, we investigated the effects of xCT overexpression in normal bronchial airway epithelial cells. We hypothesize that xCT overexpression both induces genomic instability and alters the epigenome in normal bronchial airway epithelial cells through the perturbation of intracellular metabolite levels. Through utilizing an alkaline comet assay, we discovered that xCT overexpression induces DNA damage, increasing the percentage of DNA in the comet tail by 15.1% (P=0.002). Furthermore, we found that xCT overexpression induces alterations to the histone modification landscape, most notably increasing H3K9me3 and H3K9ac by 3.2 and 3.9-fold (P=0.08) respectively. Finally, xCT overexpression shows higher tumorigenic potential through increased colony formation in a soft agar assay. Taken together, xCT overexpression in normal bronchial airway epithelial cells increases tumorigenic potential, induces metabolic reprogramming, causes higher levels of DNA damage, and alters the epigenetic landscape. Future experiments elucidating the links between these processes, including ChIP-seq and whole-genome bisulfite sequencing are currently underway. Establishing causal links between metabolic reprogramming, epigenetic alterations, and genomic instability are imperative in elucidating an effective, potentially multifaceted approach to treating early-stage lung cancer. Citation Format: Dalton Hill, Jamshedur Rahman, Christien Kluwe, Pierre P. Massion. xCT expression alters the epigenome and induces genomic instability [abstract]. In: Abstracts: AACR Special Virtual Conference on Epigenetics and Metabolism; October 15-16, 2020; 2020 Oct 15-16. Philadelphia (PA): AACR; Cancer Res 2020;80(23 Suppl):Abstract nr PO-001.

Yellow gentian root extract provokes concentration- and time-dependent response in peripheral blood mononuclear cells.

Yellow gentian (Gentiana lutea L.), a medicinal plant widely used in traditional medicine, displays multiple biological effects, ranging from beneficial to toxic. Since many promising applications have been reported so far, our aim was to evaluate its potential concentration- and time- dependent cytotoxic and genotoxic effects in vitro. To that end we exposed human peripheral blood mononuclear cells to 0.5, 1, and 2 mg/mL of yellow gentian root extract (YGRE) to determine its effects on oxidative stress parameters [pro/antioxidant balance (PAB) and lipid peroxidation], DNA damage (alkaline comet assay and chromosome aberrations), and cell viability (trypan blue exclusion test). Cell viability decreased with increasing concentrations and treatment duration. Only the lowest YGRE concentration (0.5 mg/mL) increased oxidative stress but produced minor DNA damage and cytotoxicity. At higher concentrations, redox parameters returned to near control values. The percentage of chromosome aberrations and percentage of DNA in the comet tail increased with increased YGRE concentration after 48 h and declined after 72 h of treatment. This points to the activation of DNA repair mechanism (homologous recombination), evidenced by the formation of chromosomal radial figures after 72 h of treatment with the highest YGRE concentration of 2 mg/mL. Our results suggest that YGRE, despite induction of cytotoxic and genotoxic effects, activates cell repair mechanisms that counter oxidative and DNA lesions and induce cell death in highly damaged cells. Therefore, observed protective effects of yellow gentian after longer exposure could be a result of activated repair and removal of cells with irreparable damage.

Effects of IAA on physiological response to aluminum stress and DNA damage of Trichosanthes kirilowii.

To investigate the physiological response of IAA (indoleacetic acid) to Trichosanthes kirilowii under aluminum stress and the mitigation of DNA damage, the effects of IAA (0, 10, 25, 50, 75 μmol·L-1 denoted by I0, I10, I25, I50 and I75, respectively) on antioxidant enzyme activity, malondialdehyde (MDA), photosynthetic characteristics, root activity, chlorophyll content and DNA damage of two varieties of T. kirilowii under 300 and 800 μmol·L-1 aluminum environment (denoted by Al300 and Al800, respectively) were examined in hydroponic culture experiments with Hebei Anguo (aluminium tolerant variety) and Zhejiang Puyang Trichosanthes kirilowii (aluminum sensitive variety). The results showed that the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), photosynthesis ability, and root activity of both varieties were inhibited to different degrees by aluminum stress, MDA content was significantly increased, and DNA damage was aggravated. The maximum increase of SOD, CAT and POD activities in Anguo and Puyang T. kirilowii under aluminum stress by IAA application were 15.0%, 31.2%, 72.3% and 13.8%, 26.9%, 26.4%, respectively, chlorophyll content increased by 49.9% and 17.9%, MDA accumulation decreased by 39.2% and 22.4% and fluorescence parameters were significantly improved. The treatment of 25 μmol·L-1 IAA significantly increased root activity by 159.1% and 90.9%, while 50 μmol·L-1 IAA effectively slowed the DNA tailing phenomenon in roots, with the product (OTM) value of tail DNA percentage content and tail moment being decreased by 27.6%. 10-50 μmol·L-1 IAA could effectively improve the physiological activity of T. kirilowii under aluminum stress and slow the degree of DNA damage. The tolerance of Anguo variety to aluminum stress was stronger than that of Puyang variety.

DNA damage effect of cyprodinil and thiacloprid in adult zebrafish gills.

Cyprodinil and thiacloprid are two of the most commonly used pesticides in Turkey. It is more likely to reach humans or animals due to their widespread use. This study aims to investigate whether there is a DNA damage risk due to cyprodinil and thiacloprid exposure. Zebrafish, which is used as a model organism in health and environmental research, and comet assay were chosen to demonstrate this damage. Ten zebrafish per group were exposed to 2 different concentrations for each pesticides (0.31 and 0.155 mg/L for cyprodinil and 1.64 and 0.82 mg/L for thiacloprid) for 21 days. After, gills were excised and comet assay was performed. Photos of an average of 50 cells per slide were taken and were analyzed with visual evaluation program. DNA damage was found to be increased in the 0.31 mg/L cyprodinil, 0.82 mg/L thiacloprid, and 1.64 mg/L thiacloprid treatment groups when compared to the control group (p < 0.001). Average tail DNA percentage parameter values were 9.45 ± 0.51, 10.30 ± 0.34, 11.17 ± 0.33, and 2.47 ± 0.06 respectively. Cyprodinil and thiacloprid were identified as genotoxic agents that should be investigated further.

Comparative toxicity of green and chemically synthesized CuO NPs during pregnancy and lactation in rats and offspring: Part I -hepatotoxicity

Widespread applications of nanomaterials in food and health sciences have inevitable toxicological outcomes. Among nanomaterials, copper oxide nanoparticles (CuO NPs) are commonly used in all fields due to its distinctive characteristics. The study was designed to investigate the comparative hepatotoxic effect of green (GNPs) and chemically synthesized (CNPs) CuO NPs on spargue-dawely rats and their offspring. NPs (50 and 100 mg/kg) were orally administered to rats twice a week starting before mating. After birth the parents were continued dosing while pups were only on mother feed. Antioxidant, lipid peroxidation, genotoxicity, and histology were performed on liver tissue. In addition serum biochemistry of parents and offspring was also performed. The levels of catalase, peroxidase, and glutathione were significantly lowered only in CNPs treated parents while lipid peroxidation level was increased in these groups. Maximum genotoxicity (2.3%) in terms of percent tail DNA was observed in parent rats administered with high CNPs dose while other groups did not exhibit significant variation in genetoxic parameters. Gender and dose dependent effects were observed on liver function tests especially ALP and ALT in parents however no obvious differences were observed in offspring. Furthermore, dose dependent dilation and congestion of sinusoids was observed on CNPs administration. In GNPs treated rats and offspring histological alterations were observed. The study concludes that chemically synthesized CuO NPs exhibit dose dependent toxic effects on liver as compared to green synthesized CuO NPs. Furthermore lactation does not play significant role in the hepatotoxicity of offspring though minor oxidative stress was observed only on CNPs administration. The study also shows that pharmacological application of green synthesized NPs can be accomplished due to their biocompatible nature.

Genotoxic effects of drospirenone and ethinylestradiol in human breast cells (in vitro) and bone marrow cells of female mice (in vivo)

Estrogen and progesterone congeners as found in various oral contraceptive formulations have been implicated as the cause of cancer in sex and tissue-specific targets. The mechanism of carcinogenesis by sex steroids is still debatable. In this study, we evaluated the genotoxicity induced by two components of one of the commonly used oral contraceptive formulation; drospirenone and ethinylestradiol in human breast cells (MCF-7) in vitro and in bone marrow cells of female mice in vivo. DNA damage was assessed by alkaline comet assay. Both of the drugs produced DNA damage in human breast cells at exposure concentrations which are about 100-fold and above than normally found in human blood after their lowest recommended doses. The DNA damage was produced only after metabolic activation by mice liver S-9 fraction in both cases. The co-exposure with both the compounds at median exposure levels resulted in potentiation of DNA damage. In bone marrow cells of adult female mice, both the compounds produced DNA damage at human equivalent doses after exposure was carried out repeatedly for approximately one estrus cycle (5 days). The co-administration with the compounds resulted in potentiation of DNA damage as indicated by percent tail DNA in comet assay. Thus it is concluded that drospirenone and ethinylestradiol cause DNA damage in certain target specific tissue (mammary epithelial cells) and in female bone marrow cells. The co-exposure with drospirenone and ethinylestradiol results in potentiation of genotoxicity which may pose a threat of cancer development in women taking these drugs for long periods.