Effects of abasic sites on structural, thermodynamic and kinetic properties of quadruplex structures

Abasic sites represent the most frequent lesion in DNA. Since several events generating abasic sites concern guanines, this damage is particularly important in quadruplex forming G-rich sequences, many of which are believed to be involved in several biological roles. However, the effects of abasic sites in sequences forming quadruplexes have been poorly studied. Here, we investigated the effects of abasic site mimics on structural, thermodynamic and kinetic properties of parallel quadruplexes. Investigation concerned five oligodeoxynucleotides based on the sequence d(TGGGGGT), in which all guanines have been replaced, one at a time, by an abasic site mimic (dS). All sequences preserve their ability to form quadruplexes; however, both spectroscopic and kinetic experiments point to sequence-dependent different effects on the structural flexibility and stability. Sequences d(TSGGGGT) and d(TGGGGST) form quite stable quadruplexes; however, for the other sequences, the introduction of the dS in proximity of the 3′-end decreases the stability more considerably than the 5′-end. Noteworthy, sequence d(TGSGGGT) forms a quadruplex where dS does not hamper the stacking between the G-tetrads adjacent to it. These results strongly argue for the central role of apurinic/apyrimidinic site damages and they encourage the production of further studies to better delineate the consequences of their presence in the biological relevant regions of the genome

8-oxo-7,8-dihydro-2'-deoxyguanosine as a biomarker of oxidative damage in oesophageal cancer patients: lack of association with antioxidant vitamins and polymorphism of hOGG1 and GST

International audienceThe present report was designed to investigate the origins of elevated oxidative stress measured in cancer patients in our previous work related to a case-control study (17 cases, 43 controls) on oesophageal cancers. The aim was to characterize the relationship between the levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), antioxidant vitamins and genetic susceptibility

Urinary DNA Lesions as a Biomarker for Assessing Male Reproductive Health

The study aimed to examine whether urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG) could serve as a biomarker for assessing sperm DNA integrity. Urine and semen samples were collected from 124 coke-oven workers, who had chronically been exposed to polycyclic aromatic hydrocarbons (PAHs), from a steel plant in Kaohsiung, Taiwan. The coke-oven workers were divided into two subgroups: topside-oven workers and side-oven workers. Sperm DNA integrity was assessed in terms of DNA fragmentation and 8-oxo-7,8-dihydro-2’-deoxyguanosine (8-oxodGuo). Urine samples were used to detect 1-hydroxypyrene (1-OHP) and urinary 8-OHdG, which served to assess exposure to PAHs and the whole body oxidative stress, respectively. Urinary 1-OHP concentrations were significantly higher in the topside-oven workers than the side-oven workers (p = 0.02). Sperm 8-oxodGuo concentrations were correlated with percentages of sperm fragmentation (p = 0.044), but urinary 8-OHdG levels failed to correlate with sperm 8-oxodGuo levels and with percentages of fragmentation. In conclusion, exposure to PAHs was linked to increased oxidative stress on sperm. However, urinary 8-OHdG may not be a suitable biomarker for examining sperm DNA damage associated with oxidative stress

Determination of the Product of DNA Oxidation in the Blood of Women Living in the Sub-Aral Area

To assess the impact of climatic and anthropogenic factors of the Aral Sea region on reproductive health, we examined 300 women living in the Kyzylorda region of Kazakhstan, which borders the Aral Sea region. The survey was based on comprehensive clinical-functional and laboratory studies accounting on regional environmental and ecological factors. The survey subject was the area of 2 settlements in Kyzylorda region. In both areas, it was revealed that the examined women of the age group 30-39 years old had increased values of oxidative stress indices comparison with Atasu village of Karaganda regio

Program kvalitete življenja: hrana, prehrana i zdravlje - promocija projekata

The EC Quality of Life Programme (QoL), Key Action 1 – Food, Nutrition & Health aims at providing a healthy, safe, and high-quality food supply leading to reinforced consumer’s confidence in the safety of the European food. Key Action 1 is currently supporting several European projects investigating analytical methods for food control including sensors, risk analysis, and food safety standardisation. Their objectives range from the development and validation of prevention strategies for mycotoxin formation via the development of a communication platform for Genetically Modified Organisms (GMO), validation and standardisation of diagnostic Polymerase Chain Reaction (PCR) for food-borne pathogens, up to the evaluation of the potential cancer-preventing activity of pro-and prebiotic (»SYNBIOTIC«) combinations in human volunteers. This paper also informs on future research needs in food safety.Program kvalitete življenja (QoL) Europske zajednice, Ključna akcija 1 (KA1) – Hrana, prehrana i zdravlje ima svrhu pružanja zdrave, sigurne i visokokvalitetne opskrbe hranom sa svrhom jačanja povjerenja potrošača u sigurnost europske hrane. Ključna akcija trenutno podupire nekoliko različitih europskih projekata ispitivanjem analitičkih metoda za kontrolu hrane uključivši senzore, procjenu rizika i standardizaciju sigurnosti hrane. Njihov cilj polazi od razvoja i vrednovanja strategije prevencije za stvaranje mikotoksina preko razvoja komunikacijskih platforma za genetički modificirane organizme (GMO), validacije i standardizacije dijagnostičke metode lančane reakcije polimerazom (PCR) za patogene nastale u hrani, do evaluacije potencijalne aktivnosti sprečavanja karcinoma probiotskih i pre-biotskih (“sinbiotskih”) kombinacija u humanih dobrovoljaca. U ovom radu navedene su također potrebe za daljnjim istraživanjima u području sigurnosti hrane