scholarly journals Genetic markers that determine the efficiency of repair of double-strand DNA breaks and DNA mismatch repair under the action of occupational factors

2018 ◽  
Vol 82-83 (2-3) ◽  
pp. 78-84
Author(s):  
T.A. Andruschenko ◽  
S.V. Honcharov ◽  
V.Ye. Dosenko

Introduction. Distribution of the following allelic variants of DNA repair genes: АТМ (rs664677), XRCC7 (rs7003908), and MLH1 (rs1799977) in the population of personnel of harmful and hazardous occupation has been studied. The studied polymorphisms are recognized as cancer-specific markers of various types and localization of malignant neoplasms, as well as markers of radiosensitivity/resistance to radiation exposure. Objectives of the work: to find out the significance of polymorphisms of repair genes of double-strand DNA breaks: XRCC7 (rs7003908), АТМ (rs664677), and mismatch repair: MLH1 (rs1799977) in the formation of an individual predisposition to the development of chronic diseases of the bronchopulmonary system in miners and personnel ofasbestos-cement plants. Materials and methods. Respondents of the study group was the personnel of asbestos-cement plants and miners with chronic bronchopulmonary disease; the control group was made up of personnel without diseases of the respiratory system. The genotypes of the following genes were determined by real-time polymerase chain reaction: АТМ (rs664677), XRCC7 (rs7003908), and MLH1 (rs1799977). Results. It was established that the minor alleles of ATM•T and MLH1•G, minor homozygote ATM•TT and heterozygote MLH1•AG are associated with the risk of developing chronic diseases of the bronchopulmonary system. It has been revealed that the dominant alleles of ATM•A, MLH1•A; dominant homozygotes ATM•AA; MLH1•AA and heterozygote ATM•AT contribute to resistance to the development of the respiratory system conditions. Conclusion. The following alleles: ATM•T (Р<=0,06, χ2=3,44; OR=1,44; 95 % Cl: 0,96–2,17); MLH1•G (Р<=0,002, χ2=5,06; OR=1,61; 95 % Cl: 1,04–2,49) and genotype: ATM•TT (Р<=0,01, χ2=6,61; OR=2,48; 95 % Cl: 1,16–5,31); MLH1•AG (Р<=0,002, χ2=9,00; OR=2,32; 95 % CI: 1,29–4,21) associated with the risk of bronchopulmonary conditions development have been established. Also alleles: ATM•A (Р<=0,06, χ2=3,44; OR=0,69; 95 % CI: 0,46–1,04); MLH1•A (Р<=0,002, χ2=5,06; OR=0,62; 95 % CI: 0,40–0,96) and genotype: MLH1•A/A (Р<=0,003, χ2=8,73; OR=0,43; 95 % CI: 0,24–0,79) that form resistance to the development of pulmonary system conditions in certain occupational groups have been established. Key words: SNP, ATM, XRCC7, MLH1, bronchopulmonary pathology.

2010 ◽  
Vol 32 (1) ◽  
pp. 39-47 ◽  
Author(s):  
Anna Łękawa–Ilczuk ◽  
Halina Antosz ◽  
Beata Rymgayłło–Jankowska ◽  
Tomasz Żarnowski

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1115-1125 ◽  
Author(s):  
Fei Xu ◽  
Thomas D Petes

Abstract Meiotic recombination in Saccharomyces cerevisiae is initiated by double-strand DNA breaks (DSBs). Using two approaches, we mapped the position of DSBs associated with a recombination hotspot created by insertion of telomeric sequences into the region upstream of HIS4. We found that the breaks have no obvious sequence specificity and localize to a region of ~50 bp adjacent to the telomeric insertion. By mapping the breaks and by studies of the exonuclease III sensitivity of the broken ends, we conclude that most of the broken DNA molecules have blunt ends with 3′-hydroxyl groups.


2017 ◽  
Vol 23 (26) ◽  
pp. 6459-6459
Author(s):  
Sebastian Bestgen ◽  
Carmen Seidl ◽  
Thomas Wiesner ◽  
Andreas Zimmer ◽  
Martina Falk ◽  
...  

Gerontology ◽  
2015 ◽  
Vol 62 (3) ◽  
pp. 296-303 ◽  
Author(s):  
Jin-Sun Ryu ◽  
Hyeon-Sook Koo

Werner syndrome protein (WRN) is unusual among RecQ family DNA helicases in having an additional exonuclease activity. WRN is involved in the repair of double-strand DNA breaks via the homologous recombination and nonhomologous end joining pathways, and also in the base excision repair pathway. In addition, the protein promotes the recovery of stalled replication forks. The helicase activity is thought to unwind DNA duplexes, thereby moving replication forks or Holliday junctions. The targets of the exonuclease could be the nascent DNA strands at a replication fork or the ends of double-strand DNA breaks. However, it is not clear which enzyme activities are essential for repairing different types of DNA damage. Model organisms such as mice, flies, and worms deficient in WRN homologs have been investigated to understand the physiological results of defects in WRN activity. Premature aging, the most remarkable characteristic of Werner syndrome, is also seen in the mutant mice and worms, and hypersensitivity to DNA damage has been observed in WRN mutants of all three model organisms, pointing to conservation of the functions of WRN. In the nematode Caenorhabditis elegans, the WRN homolog contains a helicase domain but no exonuclease domain, so that this animal is very useful for studying the in vivo functions of the helicase without interference from the activity of the exonuclease. Here, we review the current status of investigations of C. elegans WRN-1 and discuss its functional differences from the mammalian homologs.


2020 ◽  
Vol 15 (4) ◽  
pp. 82-90
Author(s):  
V. T. Sakhin ◽  
M. A. Grigoriev ◽  
E. V. Kryukov ◽  
S. P. Kazakov ◽  
A. V. Sotnikov ◽  
...  

Objective: to study the importance of cytokines, hepcidin, a soluble transferrin receptor, iron metabolism in the development of anemia of chronic diseases in patients with malignant neoplasms and rheumatic pathology, to identify the leading factors in the development of anemia for each of the studied groups and to develop a working classification of anemia of chronic diseases.Materials and methods. 63 patients with rheumatic pathology were examined. The study group included 41 (17 men/24 women, average age 53.4 ± 4 years) patients with anemia, the control group included 22 (9 men/13 women, age 49.3 ± 1.78 years) patients without anemia. The patients (n = 63) with stage II–IV malignant neoplasms were examined. The study group included 41 patients with anemia (34 men/7 women, age 67.1 ± 9.9 years), in the control group 22 patients without it (17 men/5 women, age 60.2 ± 14.9 years). The number of red blood cells, the hemoglobin level, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, concentrations of serum iron, total iron binding capacity (TIBC), ferritin, transferrin, C-reactive protein (CRP), transferrin saturation index (TSI), and soluble transferrin receptor (sTfR), hepcidin, interleukin (IL) – 6, – 10, tumor necrosis factor-α (TNF-α) were determined. Mann – Whitney U Test was applied to check for statistically significant differences in study samples.Results. Compared with the control group, elevated concentrations of ferritin, CRP, hepcidin, sTfR and IL-6 (p <0.05) were found for patients with rheumatic pathology and anemia and no differences were found in the concentrations of iron, TIBC, TSI, transferrin. For patients with solid malignant neoplasms and anemia, lower concentrations of iron, TIBC, TSI and higher concentrations of CRP, hepcidin, sTfR, IL-6, IL-10, TNF-α (p <0.05) are shown in comparison with the control group and there were no differences in the concentrations of ferritin, transferrin (p >0.05).Conclusion. The multicomponent anemia genesis in patients with cancer and rheumatic pathology is shown. The contribution of each mechanism to the development of anemia may vary depending on the specific nosological form. In patients with cancer, functional iron deficiency, activation of IL-6, IL-10, TNF-α synthesis and an increase in hepcidin synthesis lead to the development of anemia of chronic diseases. In patients with a rheumatic profile and anemia, a more pronounced synthesis of hepcidin and an increase IL-6 concentration are indicated. A working version of the classification of anemia of chronic diseases based on the leading pathogenetic factor is proposed (with a predominant iron deficiency, with impaired regulatory mechanisms of erythropoiesis, with insufficient production of erythropoietin).


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