DNA Damage In Lymphocytes Research Articles

DNA DOUBLE-STRANDED BREAKS AND REPAIRS IN ACUTE LEUKEMIA

Relevance: Double-strand Relevance: Errors in the damage repair system, such as double-stranded DNA breaks, can lead to mutations that will be passed on to subsequent generations of cells, and some of these mutations may have oncogenic potential.
 The study aimed to evaluate the number of double-stranded breaks and DNA repairs of peripheral blood lymphocytes in a group of conditionally healthy children and in patients diagnosed with acute leukemia (AL) to develop a method for predicting the outcome of the disease and determining the effectiveness of therapy.
 Methods: peripheral blood lymphocytes were studied: a) 38 conditionally healthy children (control group); b) 100 patients diagnosed with acute leukemia (AL); c) 14 children with relapse of the disease. Double-stranded DNA breaks/repairs were examined using the Aklides system (MEDIPAN, Germany), consisting of a fluorescent analyzer and the AKLIDES Nuk software.
 Results: In patients with T-lymphoblastic leukemia, both at admission and the end of Day 7 at the hospital, the number of 53BPI repair foci was, on average, three times higher than the number of DNA damages. In most cases, the ratio of breaks/repairs indicators during treatment did not change among patients with B-line leukemia. Double-stranded DNA breaks prevailed over repairs, with the newly established disease on the 7th, 15th day, and 3rd month of treatment.
 Overall, 22 samples were tested using RT-PCR, and results were considered as follows:1 (4%) – positive, 13 (59%) – negative, 8 (37%) -– invalid.
 Conclusion: The level of lymphocyte DNA damage in patients with B-ALL was higher than expected. In addition, the ratio of double-strand breaks to repairs remained unchanged at all stages of therapy in patients with B-ALL. The changes we suggest in these patients can be observed during and/or after maintenance therapy. Monitoring double-strand breaks/reparations was the initial step in developing a method of predicting the disease outcome and determining the therapy efficacy. The results obtained are of direct interest and require further research.

DNA DOUBLE-STRANDED BREAKS AND REPAIRS IN ACUTE LEUKEMIA

Relevance: Double-strand Relevance: Errors in the damage repair system, such as double-stranded DNA breaks, can lead to mutations that will be passed on to subsequent generations of cells, and some of these mutations may have oncogenic potential.
 The study aimed to evaluate the number of double-stranded breaks and DNA repairs of peripheral blood lymphocytes in a group of conditionally healthy children and in patients diagnosed with acute leukemia (AL) to develop a method for predicting the outcome of the disease and determining the effectiveness of therapy.
 Methods: peripheral blood lymphocytes were studied: a) 38 conditionally healthy children (control group); b) 100 patients diagnosed with acute leukemia (AL); c) 14 children with relapse of the disease. Double-stranded DNA breaks/repairs were examined using the Aklides system (MEDIPAN, Germany), consisting of a fluorescent analyzer and the AKLIDES Nuk software.
 Results: In patients with T-lymphoblastic leukemia, both at admission and the end of Day 7 at the hospital, the number of 53BPI repair foci was, on average, three times higher than the number of DNA damages. In most cases, the ratio of breaks/repairs indicators during treatment did not change among patients with B-line leukemia. Double-stranded DNA breaks prevailed over repairs, with the newly established disease on the 7th, 15th day, and 3rd month of treatment.
 Overall, 22 samples were tested using RT-PCR, and results were considered as follows:1 (4%) – positive, 13 (59%) – negative, 8 (37%) -– invalid.
 Conclusion: The level of lymphocyte DNA damage in patients with B-ALL was higher than expected. In addition, the ratio of double-strand breaks to repairs remained unchanged at all stages of therapy in patients with B-ALL. The changes we suggest in these patients can be observed during and/or after maintenance therapy. Monitoring double-strand breaks/reparations was the initial step in developing a method of predicting the disease outcome and determining the therapy efficacy. The results obtained are of direct interest and require further research.

Oxidative and DNA damage in obese patients undergoing bariatric surgery: A one-year follow-up study

The pathogenesis of obesity and related comorbidities has long been associated with oxidative stress. The excess of adipose tissue contributes to the production of free radicals that sustain both a local and a systemic chronic inflammatory state, whereas its reduction can bring to an improvement in inflammation and oxidative stress. In our work, using the fluorescent lipid probe BODIPY® 581/591 C11 and the γH2AX foci assay, a well-known marker of DNA double strand breaks (DSB), we evaluated the extent of cell membrane oxidation and DNA damage in peripheral blood lymphocytes of normal weight (NW) controls and obese patients sampled before and after bariatric surgery. Compared to NW controls, we observed a marked increase in both the frequencies of oxidized cells or nuclei exhibiting phosphorylation of histone H2AX in preoperatory obese patients. After bariatric surgery, obese patients, resampled over one-year follow-up, improved oxidative damage and reduced the presence of DSB. In conclusion, the present study highlights the importance for obese patients undergoing bariatric surgery to also monitor these molecular markers during their postoperative follow-up.

Impact of stocking density and dietary nano-zinc supplementation on stress indicators, immunity, and DNA damage in broiler chickens

Effects of stocking density (SD) and nano zinc on oxidative status, immune function, and DNA damage in broilers were examined in the current study. Totally 480 one-day-old male broilers (Ross 308) were randomly divided into 4 treatments each contained 8 replicates. A 2 ´ 2 factorial arrangement with two groups for dietary zinc (Zn) form (inorganic or nano) and two groups for SD (low = 12 birds/m2 and high = 18 birds/m2) was conducted. Basal diets based on the corn-soybean meal were formulated. Relative liver weight was lower (P<0.05) in broiler subjected high stocking density (HSD) but other lymphoid organ weights did not affect. Relative lymphoid organ weights were not affected by dietary nano zinc. HSD increased the serum corticosterone level of broiler (P<0.05) but did not affect the blood heterophil:lymphocyte ratio, serum glutathione, superoxide dismutase, and malondialdehyde levels. Dietary nano zinc had no effect on these stress indicators. Serum interferon-gamma, interleukin 12, and interleukin 18 levels were not affected by HSD. Dietary nano zinc tended to reduce the interferon-gamma level (P=0.05) but did not affect interleukin 12, and interleukin 18 levels in broiler. Eeither HSD or nano zinc had no effect on DNA damage in lymphocyte. In conclusion, HSD may decrease the relative lymphoid organ weights and increase the stress indicators but did not affect the immunity and DNA damage. Generally, dietary nano zinc had no effect on stress indicators, immunity, and DNA damage in broiler.

Effect of Electromagnetic Radiation (2.45 GHz) on Lymphocyte DNA Damage and Hematological Parameters: The Protective Role of Vitamin C

Amaç: Bu çalışmanın amacı, kanda hematolojik ve biyokimyasal değişikliklere neden olabilen 2.45 GHz elektromanyetik radyasyonun (EMR) etkilerini araştırmaktır. EMR maruziyetinin etkilerine karşı koruyucu özelliği olan Vitamin C'yi (Vit C) tercih ettik. Materyal-Metot: Bu çalışma için 18 dişi Sprague Dawley sıçanı rastgele her birinde altı hayvan bulunan üç gruba ayrıldı: Kontrol, EMR ve EMR+Vit C grupları. Kontrol grubu: gavaj ile 30 gün boyunca 0.1 ml/gün salin; EMR grubu: EMR, 30 gün boyunca 1 saat/gün; EMR+Vit C grubu: EMR, 30 gün boyunca 1 saat/gün C vitamini 250 mg/kg/gün, gavaj ile. Beyaz Kan Hücresi (WBC), Nötrofil, Lenfosit, Monosit, Eozinofil, Bazofil, Kırmızı Kan Hücresi (RBC), Hemoglobin (Hb), Hematokrit (Htc), Ortalama Eritrosit Hacmi (MCV), Kırmızı Hücre Dağılım Genişliği-SD (RDW- SD), Kırmızı Hücre Dağılım Genişliği-CV (RDW-CV), Trombosit (PLT), Ortalama Trombosit Hacmi (MPV), Trombosit Dağılım Genişliği (PDW), Trombosit Krit (PCT) ve Trombosit Büyük Hücre Oranı (P-LCR) sayıları ölçülmüştür. Comet testi ile lenfosit DNA hasarı değerlendirildi, ayrıca malondialdehit (MDA) seviyesi ve katalaz (CAT) aktivitesi değerlendirildi. Bulgular: Comet analiz skoru ve P-LCR sayıları EMR grubunda Kontrol grubuna göre arttı (p<0,05). C vitamini tedavisi sonrası comet analiz skorunda ve P-LCR sayılarında EMR grubuna göre azalma gözlemledik (p<0,05). Sonuç: Sonuçlar, bir cep telefonu tarafından üretilen frekansta EMR'nin lenfosit DNA kırılmasına neden olduğunu ve P-LCR seviyesini artırdığını göstermektedir. C vitamini, EMF maruziyetinin neden olduğu lenfosit DNA hasarını ve P-LCR seviyesini azaltıyor gibi görünmektedir.

Interaction of L-ascorbic acid and α-tocopherol in alleviating 1, 4-benzoquinone, a metabolite of benzene induced genotoxicity in male Wistar rats

ABSTRACT The present study investigated the possible protective effects of L-ascorbic acid and α-tocopherol on 1,4-benzoquinone (BQ) induced chromosomal aberrations, DNA damage and lipid peroxidation in male Wistar rats. Animals were randomly divided into five groups. The control group received normal feed and clean drinking water. The second group received single dose of BQ (3mgkg−1, ip), the third and fourth group received L-ascorbic acid (100 mgkg−1) and α-tocopherol (100mgkg−1) orally along with BQ. The fifth group received a combined dose of L-ascorbic acid (100mgkg−1) and α-tocopherol (100mgkg−1) with BQ. BQ caused significant increase in the percentage of chromosomal aberration, formation of micronuclei, DNA damage in peripheral lymphocytes and increased MDA content. However, the cotreatment with either L-ascorbic acid or α-tocopherol resulted in significant decline in the micronuclei formation, chromosomal abnormalities, DNA damage and MDA level, and restoration of mitotic indices in BQ treated animals. The protective effects of L-ascorbic acid and α-Tocopherol were found to be significantly enhanced in combined dosed treated group. The result of the present study indicated that combined supplementation of both water-soluble and lipid-soluble vitamins was more efficient at reversing the genotoxic changes induced by BQ in the bone marrow cells of Wistar rats.

Methanolic fraction of Cassia fistula L. bark exhibits potential to combat oxidative stress and possess antiproliferative activity

ABSTRACT Cassia fistula L. is well known for its traditional medicinal properties as an anti-inflammatory, hepatoprotective, antifungal, antibacterial, antimutagenic, and wound healing agent. The aim of the present study was to determine antioxidant, genoprotective, and cytotoxic potential of different fractions of C. fistula bark including hexane (CaMH), chloroform (CaMC), ethyl acetate (CaME), and methanol (CaMM). Among all the fractions studied, CaMM exhibited maximal radical scavenging activity in antioxidant DPPH assay, Superoxide anion radical scavenging assay and nitric oxide radical scavenging assay displayed an IC50 value of 18.95, 29.41, and 13.38 µg/ml, respectively. CaMM fraction possessed the highest phenolic (130.37 mg gallic acid equivalent/g dry weight of extract) and flavonoid (36.96 mg rutin equivalent/g dry weight of fraction) content. Data demonstrated significant positive correlation between polyphenol levels and radical scavenging activity. Single cell gel electrophoresis (Comet assay) exhibited genoprotective potential of C. fistula bark fractions against DNA damage induced by hydrogen peroxide (H2O2) in human lymphocytes. CaMM fraction displayed highest protective ability against H2O2 induced-toxicity as evidenced by significant decrease in % tail DNA content from 30 to 7% at highest concentration (200 µg/ml). CaMM was found to be rich in catechin, gallic acid, chlorogenic acid, and kaempferol. The phenolic content and antioxidant ability of the fractions was markedly negatively correlated with H2O2- induced DNA damage in human lymphocytes. Cytotoxic potential was evaluated against dermal epidermoid carcinoma (A431), pancreatic (MIA PaCa-2) and brain glioblastoma (LN-18) cancer cell lines using MTT assay. Results showed that C. fistula bark fractions possessed highest toxicity against the skin carcinoma cells. CaMM fraction reduced over 50% cell growth at the concentration of 76.72 µg/ml in A431 cells. These findings suggest that fractions of C. fistula bark exhibit potential to be considered as therapeutic agents in various carcinomas.

DNA damage and protective effects of placental extracts in blood lymphocytes and lymphoid organs of mice exposed to gamma irradiation

DNA damage was evaluated in blood lymphocytes and lymphoid organs including lymph nodes, bone marrow, spleen and thymus of C3H/He N mice exposed to gamma irradiation. Furthermore, the protective effects of placental extracts (PE) on DNA damage were determined. Mice were exposed to gamma irradiation (high dose of 7 Gy, 137Cs, 0.8 Gy/min) with or without PE treatment and comet assays were performed to determine DNA damage occurring in the lymphocytes, lymph nodes, bone marrow, spleen and thymus of mice. In the pre- and post-gamma irradiation exposure groups, the Olive tail moments of blood lymphocytes and lymphoid organs were significantly increased, compared with controls. The highest DNA damage was revealed in lymphocytes, and the lowest in bone marrow. Post-gamma irradiation exposure with intramuscular injected PE significantly decreased DNA damage in blood lymphocytes and lymph nodes, but pre-gamma irradiation exposure with PE significantly decreased DNA damage in blood lymphocytes, lymph nodes, and bone marrow. No change of DNA damage was found in non-irradiated PE treatment groups. Taken together, the present study suggests that acute gamma radiation exposure induced significant DNA damage and PE can attenuate this damage in blood lymphocytes and lymphoid organs of mice.

Ratio-dependent effects of photoactivated hypericin and manumycin A on their genotoxic and mutagenic potential

Natural compounds originated from plants and microorganisms and their combinations are currently being investigated as a possible treatment for several diseases including cancer. Hypericin (photodynamically-active pigment from Hypericum perforatum L.) and manumycin A (inhibitor of farnesyltransferase from Streptomyces parvulus) belong to the chemicals potentially applicable in clinical practice. In this study we evaluated potential cytotoxic (via trypan blue exclusion test), genotoxic (via DNA-topology and comet assays), and mutagenic effects (via bacterial reverse mutation test) of these compounds and their combinations considering the molecular mechanism of their action in cell-free and cellular systems. Our results did not reveal neither cytotoxic nor mutagenic activities of tested compounds and their combinations. Regarding the genotoxic potential, no damage of plasmid DNA in cell-free system was detected. On the other hand, photoactivated hypericin and manumycin A were able to induce primary DNA damage in human lymphocytes analyzed by comet assay. The possible antagonistic interactions between these two metabolites were estimated using SynergyFinder software analysis and experimental data obtained from comet assay. Our findings indicate that not only the presence of substances, but also their ratio plays an important role in resulting effects of the combined treatment in cellular system.

Utility of comet assay of DNA damage in the detection of malignant transformation of chronic liver cirrhosis

Early detection of hepatocellular carcinoma (HCC) remains a great challenge in laboratory medicine. This study aimed to assess the ability to use the degree of DNA damage (using the comet assay) for the early detection of malignant transformation of liver cirrhosis (LC) to HCC. We used alkaline comet assay for measuring DNA damage in peripheral blood lymphocytes in 50 patients with chronic LC and 50 patients with HCC. Fifty healthy individuals served as a control group. We compared the results of comet assay parameters with alpha fetoprotein as a relevant traditional marker. The HCC group was associated with a significantly higher tail intensity (p=.004), tail moment (p=.016), total area (p=.003), total intensity (p=.010), width (p=.005), and a significantly lower head intensity (.004) when compared to the LC group. Good areas under the curve (AUCs) were found for total area (0.890), head intensity (0.880) and tail intensity (0.880), making it useful for discrimination between HCC and LC groups. Lower head intensity, higher tail intensity, tail moment, total area and width were found to be independent risk factors for HCC on top of LC. Measuring DNA damage using the Alkaline comet assay technique can be considered a sensitive and reliable diagnostic tool for early neoplastic transformation of advanced LC.

The effects of medical linear accelerator X-rays on human peripheral blood lymphocytes in the presence of glucosamine.

Glucosamine is widely prescribed as a dietary supplement used to treat arthritis. In this study, the radioprotective ability of glucosamine was evaluated against radiation-induced genotoxicity and cytotoxicity in human peripheral blood lymphocytes. Blood samples were collected from five healthy male donors and were divided into four groups. Isolated lymphocytes and blood samples were treated with 10µM of glucosamine for 2h before exposure to 2Gy radiation. The radioprotective potential of glucosamine was assessed by micronucleus assay, reactive oxygen species (ROS) level analysis, and flow cytometry. Irradiation significantly increased the micronuclei frequency as compared to the control group. Contrary to that pretreatment with glucosamine before irradiation significantly reduced the frequency of micronuclei. Furthermore, pretreatment with glucosamine significantly prevented the percentage of apoptotic lymphocytes. Also, glucosamine pretreatment significantly reduced the production of ROS in irradiated lymphocytes. This study shows glucosamine to be a potent radioprotector against radiation that induces DNA damage and apoptosis in human lymphocytes. Several additional in vivo and in vitro studies are needed before glucosamine can be considered as a radioprotective candidate in patients undergoing radiation therapy.

Anticarcinogenic impact of extracellular vesicles (exosomes) from cord blood stem cells in malignant melanoma: A potential biological treatment.

Incidence of Malignant Melanoma has become the 5th in the UK. To date, the major anticancer therapeutics include cell therapy, immunotherapy, gene therapy and nanotechnology-based strategies. Recently, extracellular vesicles, especially exosomes, have been highlighted for their therapeutic benefits in numerous chronic diseases. Exosomes display multifunctional properties, including inhibition of cancer cell proliferation and initiation of apoptosis. In the present in vitro study, the antitumour effect of cord blood stem cell (CBSC)-derived exosomes was confirmed by the CCK-8 assay (p < 0.05) on CHL-1 melanoma cells and improve the repair mechanism on lymphocytes from melanoma patients. Importantly, no significant effect was observed in healthy lymphocytes when treated with the exosome concentrations at 24, 48 and 72 h. Comet assay results (OTM and %Tail DNA) demonstrated that the optimal exosome concentration showed a significant impact (p < 0.05) in lymphocytes from melanoma patients whilst causing no significant DNA damage in lymphocytes of healthy volunteers was 300 μg/ml. Similarly, the Comet assay results depicted significant DNA damage in a melanoma cell line (CHL-1 cells) treated with CBSC-derived exosomes, both the cytotoxicity of CHL-1 cells treated with CBSC-derived exosomes exhibited a significant time-dependent decrease in cell survival. Sequencing analysis of CBSC exosomes showed the presence of the let-7 family of miRNAs, including let-7a-5p, let-7b-5p, let-7c-5p, let-7d-3p, let-7d-5p and two novel miRNAs. The potency of CBSC exosomes in inhibiting cancer progression in lymphocytes from melanoma patients and CHL-1 cells whilst causing no harm to the healthy lymphocytes makes it a potential candidate as an anticancer therapy.

Investigation of the antioxidant status and the number of double-stranded DNA breaks in models of brain tumor lesion by metastases of non-small cell lung cancer in vivo

Purpose of the study. Evaluation of the antioxidant status and DNA damage in tissues of subcutaneous xenografts of non-small cell lung cancer and in peritumoral tissues created using the A549 and H1299 cell cultures.Materials and methods. The study included 35 intact male Balb/c Nude immunodeficient mice. Cell lines A549 and H1299 were used as transplantable tumor biomaterial. A CDX model was created in accordance with the protocol for supratentorial injections (Ozawa T., James C. D., 2010) adapted for this experiment. Growth rates were controlled and intracranial xenografts were visualized using a high-resolution micro-CT system. The activity of catalase and superoxide dismutase was determined with non-denaturing electrophoresis in 8 % and 12 % polyacrylamide gel. The concentrations of sulfhydryl groups were determined according to Ellman. The DNA damage in lymphocytes was determined by the comet assay.Results. The experiment resulted in the creation of models of brain tumors characterized by intracranial growth pattern in 100 %. The activity of catalase in the studied lysates of intracranial xenografts, peritumoral tissue and healthy tissues of tumor-bearing animals in all experimental groups increased statistically significantly relative to the healthy tissue of intact animals, and the greatest differences from the control were recorded in the group of animals with implanted H1299 culture at a concentration of 1 × 106 . Superoxide dismutase activity in the studied lysates of intracranial xenografts and peritumoral tissues statistically significantly increased compared to the control sample in all experimental groups. The highest increase in the SOD activity was observed in the tissues of intracranial xenografts with the highest tumor load, which amounted to 28.8 % and 32.9 % of the changes relative to the control sample. A statistically significant increase in the concentration of SH-groups relative to the control sample in tumor tissue lysates was revealed in all experimental groups, and the highest concentration (36.2 ± 0.47) was observed in the group of experimental animals with the highest tumor load. Percentage change in tail moment (DNA damage indicator) in groups O1, O2, O3 and O4 increased statistically significantly compared to the control sample by 55.8 %, 111.8 %, 97.3 % and 170 %, respectively.Conclusions. The observed increase in the activity of the antioxidant defense system, accumulation of oxidative modifications of proteins, and an increase in DNA double-strand breaks in the tissues of intracranial xenografts of non-small cell lung cancer in vivo suggest that the created models reflect processes similar to those in tumors of human non-small cell lung cancer.

Increased oxidative and chromosomal DNA damage in patients with ankylosing spondylitis: its role in pathogenesis.

Increased DNA damage has been suggested to contribute to the pathogenesis of chronic inflammatory diseases, but controlled studies are lacking in ankylosing spondylitis (AS). Therefore, we assessed oxidative stress, oxidative DNA damage, chromosomal DNA damage, cell proliferation and cell death in the peripheral blood lymphocytes of patients with AS as well as the possible role of DNA damage in the development of the disease. In total, 25 newly diagnosed AS patients who had not received anti-inflammatory agents and 25 healthy controls were recruited. Oxidative DNA damage was assessed by plasma 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, and chromosomal DNA damage was assessed by the cytokinesis-block micronucleus cytome (CBMN-cyt) method. Compared to controls, the micronucleus (MN) frequencies, nucleoplasmic bridge (NPB) frequencies, nuclear bud (NBUD) frequencies, apoptotic cell frequencies, necrotic cell frequencies and plasma 8-OHdG levels were significantly higher in patients with AS (p < 0.001, p < 0.05, p < 0.01, p < 0.001, p < 0.001, and p < 0.001, respectively), and the metaphase cell numbers, binucleated (BN) cell frequencies and nuclear division index (NDI) values were significantly lower in patients with AS (p < 0.01, p < 0.001 and p < 0.001, respectively). Thus, the present findings suggested that oxidative stress, oxidative DNA damage, and chromosomal DNA damage may be involved in the pathogenesis of AS similar to other chronic inflammatory diseases. In addition, the increased plasma 8-OHdG levels, MN frequencies, NPB frequencies and NBUD frequencies in AS patients may reflect an increased cancer risk.

DNA damage and antioxidant capacity in COPD patients with and without lung cancer

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the lower airways, and COPD patients show two to five times higher risk of lung cancer than smokers with normal lung function. COPD is associated with increased oxidative stress, which may cause DNA damage and lung carcinogenesis. Our aim was to evaluate DNA damage and oxidative stress (lipid peroxidation and antioxidant status) and their relationship in patients with COPD with and without lung cancer. We evaluated 18 patients with COPD, 18 with COPD with lung cancer, and 18 controls (former or current smokers). DNA damage was evaluated in peripheral blood lymphocytes using a comet assay; the concentration of malondialdehyde (MDA) and hydrophilic antioxidant performance (HAP) were measured in the plasma. DNA damage was higher in patients with COPD with cancer than in the controls (p = 0.003). HAP was significantly lower in patients with COPD with cancer than in those without cancer and controls. The presence of lung cancer and COPD showed a positive association with DNA strand breaks and the concentration of MDA. COPD with lung cancer was associated with elevated DNA damage in peripheral lymphocytes, and cancer and COPD showed a positive correlation with DNA damage. The antioxidant capacity showed a negative association with the interaction COPD and cancer and presence of COPD. The mechanisms underlying the increased incidence of lung cancer in COPD are unknown; DNA damage may be involved. Further research may provide insights into their development and treatment.

Effects of metformin on lymphocyte DNA damage in obese individuals among Kazakh population

Background and aimsThe global obesity epidemic is growing worldwide and its further growth is expected in the future. In obesity, the formation of reactive oxygen species (ROS) and cytokines is normally observed, which damage the genetic material. The purpose of this study was to assess lymphocyte DNA damage before and after metformin use in obese individuals. NoveltyThe novelty of the article is that for the first time DNA damage in lymphocytes before and after the use of metformin in obese individuals among Kazakh population was studied. MethodsIndirect immunofluorescence analysis using the AKLIDES apparatus was used for the quantitative determination of phosphorylated γ-H2AX (Ser 139) and 53BP1 in order to analyze DNA breaks in the lymphocytes. ResultsThe data indicating premature cell aging in the visceral adipose tissue in obese individuals were obtained. An increased hypoxia was observed in combination with an increase in γ-H2AX foci. DNA damage monitoring may become an important part of clinical studies of obesity. Advanced methods to diagnose obesity with early detection of precancerous changes imply a personalized approach, which is ineffective without data from genomic studies. ConclusionThis study showed that metformin at a dose of 850 mg/day for 3 months for the treatment of obesity (BMI more than 30 kg/m2) resulted in a decrease in DNA breaks in the lymphocytes.

Lymphocyte DNA damage in sepsis and septic-shock intensive-care patients: Damage is greater in non-intubated patients.

Sepsis is an excessive host response to infection; septic shock is a more severe clinical condition. We studied 43 sepsis patients, 32 septic-shock patients, and a group of healthy controls. The patients' Sequential Organ Failure Assessment (SOFA) and Acute Physiology and Chronic Health Evaluation (APACHE) 2 score were much higher in the septic-shock group than in the sepsis group. We used the comet assay to measure lymphocyte DNA damage; the damage scores were significantly higher in both the sepsis and the septic-shock groups compared to the healthy controls. There was no statistically significant difference between the sepsis and septic-shock groups. We also compared DNA damage levels of intubated vs. non-intubated patients. DNA damage was significantly higher in non-intubated patients compared to intubated patients, for both the sepsis and the septic-shock groups. Early intubation may be beneficial in non-intubated patients who have high levels of DNA damage.

Paraquat induced oxidative stress, DNA damage, and cytotoxicity in lymphocytes

Paraquat (PQ) is a herbicide belonging to the group of bipyridylium salts. The objective of this study was to evaluate oxidative stress, DNA damage, and cytotoxicity induced by paraquat in peripheral lymphocyte cells in vivo as well as pathological changes in various tissues. For this purpose, 28 male Wistar rats in 6 different groups were poisoned by paraquat gavage and blood samples were taken from the hearts of rats after during the poisoning period. Oxidative stress, DNA damage, cell membrane integrity, serum lactate dehydrogenase, and cytotoxicity, were investigated by Ferric Reducing Antioxidant Potential (FRAP) test, alkaline comet assay, measuring serum lactate dehydrogenase (LDH), Hoechst staining and flow cytometry with propidium iodide (PI) respectively. The lung, kidney, and liver tissues were also examined pathologically. Paraquat caused dose-dependent DNA damage in peripheral lymphocyte cells and significant oxidative cell membrane damage. The most damage was caused by a single dose of 200 mg/kg b.w of paraquat by gavage. The gradual exposure to a dose of 300 mg/kg b.w of paraquat showed less damage, which could be due to the activation of the antioxidant defense mechanism.

In vitro evaluation of zearalenone toxicity by comet assay.

The aim of this study was to reveal the potentially genotoxic effect of zearalenone on bovine lymphocytes by comet assay in vitro. The bovine lymphocytes were exposed to various zearalenone concetrations (50; 10; 2; 0.4 and 0.08 ppm). The viability and DNA damage of lymphocytes was monitored after 2 h, 24 h, 48 h and 72 h. After 2 hours of zearalenone exposure, statistically significant DNA damage occurred at all tested concentrations of 0.08 ppm (12.2±1.25; p⟨0.05), 0.4 ppm (12.7±0.88; p⟨0.01), 2 ppm (12.0±0.51; p⟨0.01), 10 ppm (11.2±0.47; p⟨0.01) and at 50 ppm (14.2±0 61; p⟨0.001). Significantly greater DNA damage was also found after 24 h, 48 h and 72 h. The obtained results showed that zearalenone may induce DNA damage of the bovine lymphocytes.

Reflection of p53 phenotype in tumor tissue by genotypic variants in glutathione S-transferases: An association with DNA damage in lung adenocarcinoma

BackgroundGenetic deficiency of glutathione S-transferase (GST) results in the accumulation of tobacco carcinogens. Consequently, the elevated risk of lung carcinoma is due to increased DNA damage and p53 caretaker gene mutational frequency. ObjectiveWhether GSTM1, GSTT1 deletion, and GSTP1 Ile105Val variants genotypes are associated with the relative risk of developing p53 mutant expression and DNA damage in patients with lung adenocarcinoma. MethodsGenetic polymorphisms in GSTM1 (+/−), GSTT1 (+/−), and GSTP1 (Ile 105 Val) were identified using restriction fragment length PCR. Subsequently, the p53 phenotype was categorized as the mutant type (>50 % and ++/+++ intensity on immunohistochemistry). Lymphocytic DNA damage was assessed using a comet assay. ResultsSmoking pack-years [median (Q1-Q3); 3.5; 37.3–60.5] were associated with p53 mutant expression. Pack-years in the wild-type p53 expression group (38; 18.5–48.5, p = 0.01). The GSTM1 (−/−) null genotype was significantly associated with the risk of p53 mutant expression (RR: 1.81, p = 0.03). GSTP1 (Val/Val) also showed a significant relative risk for p53 mutant phenotype (RR: 2.23, p = 0.04). In contrast, GSTT1 was not associated with the p53 phenotype. GSTM1 (−/−)/GSTP1 (Val/Val) combined genotype showed a significant additive effect on p53 mutant phenotypic expression (RR: 4.0, p = 0.019). DNA damage was significantly associated with GSTM1 (−/−), GSTT1 (−/−) deletion genotypes, and smoking (p = 0.001, p = 0.002 and p < 0.0001, respectively). However, the p53 phenotype was not associated with DNA damage in lymphocytes. ConclusionGSTM1 (−/−) and GSTP1 (Val/Val) genotypes increased the relative risk of the p53 mutant phenotype by two-fold. GSTM1 (−/−)/GSTP1 (Val/Val) amplified the risk of the p53 mutant phenotype by four-fold. DNA damage was significantly associated with smoking, GSTM1, and GSTT1 deletions.