Measuring Oxidative DNA Damage With 8-Hydroxy-2'-Deoxyguanosine Levels in Patients With Laryngeal Cancer

Tocolytic treatment and maternal characteristics, obstetric outcomes, and offspring childhood outcomes among births at and after 37 weeks of gestation: the Japan environment and children's study

PURPOSE

To evaluate differences in maternal characteristics and obstetric and offspring childhood outcomes between births at and after 37 weeks of gestation (referred to as term and post-term births) according to the use of tocolytic treatment.

METHODS

Data for 63,409 women with singleton births at and after 37 weeks of gestation were analyzed using data from the Japan Environment and Children's Study (JECS). We compared maternal characteristics, obstetric outcomes, and offspring childhood outcomes between term and post-term births exposed and not exposed to tocolytic treatment. Additionally, multivariable logistic regression models were used to calculate adjusted odds ratios for offspring childhood outcomes with significant between-group differences in the univariable analysis, with term and post-term births without tocolytic agents as the reference group.

RESULTS

We observed differences in maternal characteristics and obstetric outcomes between term and post-term births exposed and not exposed to tocolytic treatment. The incidence of offspring childhood developmental disorders showed no significant between-group differences. However, participants exposed to tocolytic agents had higher incidence of offspring childhood allergic disorders. The adjusted odds ratio for any of the offspring childhood allergic disorders in term and post-term births with tocolytic agents was 1.08 (95% confidence interval, 1.03-1.13).

CONCLUSION

This study found no significant difference in the incidence of offspring developmental disorders between term and post-term births exposed and not exposed to tocolytic treatment. However, tocolytic treatment was associated with differences in maternal characteristics and obstetric outcomes, along with a marginal increase in the incidence of childhood allergic disorders in offspring.

Urinary 8-hydroxy-2'-deoxyguanosine levels and preterm births: a prospective cohort study from the Japan Environment and Children's Study

OBJECTIVES

To evaluate the association between urinary 8-hydroxy-2'-deoxyguanosine (U8-OHdG) level-a marker of oxidative stress-and the incidence of preterm births (PTBs).

DESIGN

Prospective cohort study.

SETTING

The Japan Environment and Children's Study (JECS).

PARTICIPANTS

Data from 92 715 women with singleton pregnancies at and after 22 weeks of gestation who were enrolled in the JECS, a nationwide birth cohort study, between 2011 and 2014 were analysed. U8-OHdG levels were assessed once in the second/third trimester using liquid chromatography-tandem mass spectrometry. Participants were categorised into the following three or five groups: low (<1.95 ng/mg urinary creatinine (Cre)), moderate (1.95-2.94 ng/mg Cre) and high (≥2.95 ng/mg Cre) U8-OHdG groups, or groups with <1.87, 1.87-2.20, 2.21-2.57, 2.58-3.11 and ≥3.12 ng/mg Cre. For stratification, participants with representative causes for artificial PTB were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

Adjusted OR (aOR) for PTB before 37 and 34 weeks of gestation were calculated using a multivariable logistic regression model while adjusting for confounding factors; the moderate or lowest U8-OHdG group was used as the reference, respectively.

RESULTS

The aORs for PTB before 37 weeks of gestation in the high U8-OHdG group were 1.13 (95% CI 1.05 to 1.22) and 1.13 (95% CI 1.04 to 1.23) after stratification. The aOR for PTB before 37 weeks in the fourth group was 0.90 (95% CI 0.81 to 0.99). After stratification, the aORs for PTB before 37 and 34 weeks in the fifth group were 1.15 (95% CI 1.03 to 1.29) and 1.46 (95% CI 1.08 to 1.97), respectively.

CONCLUSIONS

High U8-OHdG levels were associated with increased PTB incidence, especially in participants without representative causes for artificial PTB. Our results can help identify the mechanisms leading to PTB, considering the variable aetiologies of this condition; further validation is needed to clarify clinical impacts.

The Road to Malignant Cell Transformation after Particulate Matter Exposure: From Oxidative Stress to Genotoxicity

In cells, oxidative stress is an imbalance between the production/accumulation of oxidants and the ability of the antioxidant system to detoxify these reactive products. Reactive oxygen species (ROS), cause multiple cellular damages through their interaction with biomolecules such as lipids, proteins, and DNA. Genotoxic damage caused by oxidative stress has become relevant since it can lead to mutation and play a central role in malignant transformation. The evidence describes chronic oxidative stress as an important factor implicated in all stages of the multistep carcinogenic process: initiation, promotion, and progression. In recent years, ambient air pollution by particulate matter (PM) has been cataloged as a cancer risk factor, increasing the incidence of different types of tumors. Epidemiological and toxicological evidence shows how PM-induced oxidative stress could mediate multiple events oriented to carcinogenesis, such as proliferative signaling, evasion of growth suppressors, resistance to cell death, induction of angiogenesis, and activation of invasion/metastasis pathways. In this review, we summarize the findings regarding the involvement of oxidative and genotoxic mechanisms generated by PM in malignant cell transformation. We also discuss the importance of new approaches oriented to studying the development of tumors associated with PM with more accuracy, pursuing the goal of weighing the impact of oxidative stress and genotoxicity as one of the main mechanisms associated with its carcinogenic potential.

Identification of novel factors that affect the onset of idiopathic chronic pancreatitis: The role for microRNA-323b-5p

BACKGROUND

The c.194+2 T>C variant of serine protease inhibitor Kazal type 1 (SPINK1) is a known genetic risk factor found in Chinese patients with idiopathic chronic pancreatitis (ICP), but the early-onset mechanisms of ICP are still unclear.

METHODS

Complementary experimental approaches were used to pursue other potential pathologies in the present study. The serum level of SPINK1 of ICP patients in the Han population in China was detected and verified by an enzyme-linked immunosorbent assay. Next, differentially expressed proteins and microRNAs from plasma samples of early-onset and late-onset ICP patients were screened by proteomic analysis and microarray, respectively.

RESULTS

Combined with these advanced methods, the data strongly suggest that the regulatory effects of microRNAs were involved in the early-onset mechanism of the ICP by in vitro experiments. There was no significant difference in the plasma SPINK1 expression between the early-onset ICP and the late-onset patients. However, the expression of plasma glutathione peroxidase (GPx3) in early-onset ICP patients was markedly lower than that in late-onset ICP patients, although the level of hsa-miR-323b-5p was lower in late-onset patients compared to the early-onset ICP group. In vitro experiments confirmed that hsa-miR-323b-5p could increase apoptosis in caerulein-treated pancreatic acinar cells and inhibit the expression of GPx3.

CONCLUSIONS

The up-regulated hsa-miR-323b-5p might play a crucial role in the early-onset mechanisms of ICP by diminishing the antioxidant activity through the down-regulation of GPx3.

Effects of Dietary Phytochemicals on DNA Damage in Cancer Cells

With the increasing incidence of cancer worldwide, the prevention and treatment of cancer have garnered considerable scientific attention. Traditional chemotherapeutic drugs are highly toxic and associated with substantial side effects; therefore, there is an urgent need for developing new therapeutic agents. Dietary phytochemicals are important in tumor prevention and treatment because of their low toxicity and side effects at low concentrations; however, their exact mechanisms of action remain obscure. DNA damage is mainly caused by physical or chemical factors in the environment, such as ultraviolet light, alkylating agents and reactive oxygen species that cause changes in the DNA structure of cells. Several phytochemicals have been shown inhibit the occurrence and development of tumors by inducing DNA damage. This article reviews the advances in phytochemical research; particularly regarding the mechanisms related to DNA damage and provide a theoretical basis for future chemoprophylaxis research.

Urinary 8-hydroxy-2'-deoxyguanosine levels and small-for-gestational age infants: a prospective cohort study from the Japan Environment and Children's Study

OBJECTIVES

To evaluate the association between the urinary 8-hydroxy-2'-deoxyguanosine (U8-OHdG) levels and the incidence of small-for-gestational age (SGA) infants and to assess the utility of U8-OHdG as a biomarker to predict the incidence of SGA infants.

DESIGN

Prospective cohort study.

SETTING

The Japan Environment and Children's Study.

PARTICIPANTS

Data of participants enrolled in the Japan Environment and Children's Study, a nationwide birth cohort study, between 2011 and 2014 were analysed; 104 062 fetal records were analysed. Data of women with singleton pregnancies ≥22 weeks of gestation were analysed.

PRIMARY AND SECONDARY OUTCOME MEASURES

U8-OHdG levels were assessed using liquid chromatography-tandem mass spectrometry. Participants were categorised into the following three groups according to the quartile of the distribution of U8-OHdG: low U8-OHdG (<1.95 ng/mgCre), moderate U8-OHdG (the combined second and third quartiles; 1.95-2.95 ng/mgCre) and high U8-OHdG (>2.95 ng/mgCre) groups. Additionally, participants in the 90th percentile for U8-OHdG levels were analysed. Odds ratios (ORs) for SGA infants (<-1.5 and <-2.0 SD) were calculated using a logistic regression model while adjusting for confounding factors; the moderate U8-OHdG group was used as a reference. The cut-off value of U8-OHdG to predict the incidence of SGA infants was calculated using a receiver operating characteristic (ROC) curve analysis.

RESULTS

Data of 80 212 participants were analysed. The adjusted ORs for SGA infants (<-1.5 and<-2.0 SD) in the high U8-OHdG group were 1.16 (95% CI 1.07 to 1.25) and 1.22 (95% CI 1.07 to 1.38). The cut-off value of U8-OHdG (3.26 ng/mgCre) showed a poor ability to predict SGA infants (sensitivity, 21.9%; specificity, 83.6%; area under the ROC curve, 0.530).

CONCLUSIONS

Elevated U8-OHdG levels were associated with an increased incidence of SGA infants. However, this parameter would not be a useful screening tool for predicting SGA infants owing to its low sensitivity and specificity.

Effect of Preconception Selenium Intake on the Risk for Gestational Diabetes: The Japan Environment and Children's Study

Selenium (Se) acts as a cofactor of antioxidant enzymes. Preconception care may reduce the risk of gestational diabetes mellitus (GDM). We examined the association between preconception Se intake and the risk of GDM in Japanese women. Using the Japan Environment and Children’s Study database, we identified 92,764 Japanese women recruited between January 2011 and March 2014. Participants were categorized into five groups according to preconception Se intake quintiles (Q1 and Q5 were the lowest and highest Se intake groups, respectively). GDM was categorized as early-onset (Eo-GDM) or late-onset (Lo-GDM) diagnosed before or after 24 weeks, respectively. Multiple logistic regressions were performed to identify the effect of preconception Se intake on GDM, Eo-GDM, and Lo-GDM. Using Q3 (the middle Se intake group) as the reference, a multiple logistic regression analysis showed that the highest (Q5) Se intake group demonstrated increased risks of GDM (adjusted odds ratio (aOR): 1.15, 95% confidence interval (CI): 1.01–1.30) and the lowest (Q1) Se intake group had increased risks of Lo-GDM (aOR: 1.19, 95% CI: 1.01–1.41). Thus, both high and low preconception Se intakes increase risks of glucose intolerance during pregnancy. This finding may indicate new recommendations for preconception Se intake to prevent GDM.

Evaluation of the Erythrocyte Membrane in Head and Neck Cancer Patients

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous and complex disease, both from a clinical and molecular point of view. The prolonged use of alcohol and tobacco, along with the release of tumor secretions can modulate blood cells, such as erythrocytes. Here, this study was conducted with 24 patients diagnosed with HNSCC and an equal number of healthy individuals are matched by age and gender. The levels of lipid peroxidation were measured using the individual plasma, while for lipid concentrations, identification and quantification Na, K-ATPase activity and osmotic fragility, the red blood cell concentrate were used. The release of TBARS was significantly higher in patients with HNSCC. The lipid profile assays demonstrated a rearrangement of the erythrocyte membrane due to a decrease in total phospholipids and phosphatidylethanolamine followed by an increase in total cholesterol and phosphatidylcholine. Na, K-ATPase activity also increased. Erythrocytes were more fragile in patients with HNSCC than in health individuals. Therefore, the membrane of erythrocytes were rearranged and Na, K-ATPase function altered in the HNSCC patients. Our findings suggests that the alcohol, tobacco and tumor secretion modulate in a specific manner that the erythrocytes membranes of these patients making this system a potential tool for HNSCC biomarker of tumor progression.

Urinary 8-OHdG as a Biomarker for Oxidative Stress: A Systematic Literature Review and Meta-Analysis

Oxidative stress reflects a disturbance in the balance between the production and accumulation of reactive oxygen species (ROS). ROS are scavenged by the antioxidant system, but when in excess concentration, they can oxidize proteins, lipids, and DNA. DNA damage is usually repaired, and the oxidized products are excreted in urine. 8-hydroxy-2-deoxyguanosine is considered a biomarker for oxidative damage of DNA. It is needed to define background ranges for 8-OHdG, to use it as a measure of oxidative stress overproduction. We established a standardized protocol for a systematic review and meta-analysis to assess background ranges for urinary 8-OHdG concentrations in healthy populations. We computed geometric mean (GM) and geometric standard deviations (GSD) as the basis for the meta-analysis. We retrieved an initial 1246 articles, included 84 articles, and identified 128 study subgroups. We stratified the subgroups by body mass index, gender, and smoking status reported. The pooled GM value for urinary 8-OHdG concentrations in healthy adults with a mean body mass index (BMI) ≤ 25 measured using chemical methods was 3.9 ng/mg creatinine (interquartile range (IQR): 3 to 5.5 ng/mg creatinine). A significant positive association was observed between smoking and urinary 8-OHdG concentrations when measured by chemical analysis. No gender effect was observed.

Pretreatment Serum Uric Acid as an Efficient Predictor of Prognosis in Men with Laryngeal Squamous Cell Cancer: A Retrospective Cohort Study

Purpose

Uric acid (UA) is a major antioxidant molecule that has been hypothesized to have a protective effect against cancer-induced oxidative damage. The aim of the present study was to investigate whether preoperative levels of serum UA are associated with the prognosis of laryngeal squamous cell cancer (LSCC).

Methods

A total of 814 male LSCC patients (followed up for five years) and 814 normal control subjects were enrolled from January 2007 to December 2011. The rates of total mortality and cancer mortality were 23.46% and 21.36%, respectively. The prevalence of overall survival (OS), disease-free survival (DFS), and cancer-specific survival (CSS) was analysed using the Kaplan-Meier method. Univariate and multivariate Cox regression models were evaluated to identify UA as a prognostic factor.

Results

The serum UA and UA/Cr (creatinine) ratio levels were significantly reduced (P < 0.001 for both) in the LSCC group compared with the control group. The applied multivariate Cox regression model analysis found that low levels of UA and the UA/Cr ratio were independent poor prognostic factors for OS (UA (HR (95% CI) = 1.458 (1.095–1.942)), UA/Cr ratio (HR (95% CI) = 1.337 (1.004–1.780))), DFS (UA (HR (95% CI) = 1.504 (1.131–2.001)), UA/Cr ratio (HR (95% CI) = 1.376 (1.030–1.839))), and CSS (UA (HR (95% CI) = 1.494 (1.109–2.012)), UA/Cr ratio (HR (95% CI) = 1.420 (1.049–1.923))). The patients with high UA (>0.310 mmol/l) and UA/Cr ratio (>3.97) experienced five more years of OS, DFS, and CSS than did patients with low UA (<0.310 mmol/l) and UA/Cr ratio (<3.97) levels.

Conclusion

High preoperative UA serum levels were identified as an independent prognostic factor associated with improved clinical outcomes among LSCC patients.

CZ-7, a new derivative of Claulansine F, ameliorates 2VO-induced vascular dementia in rats through a Nrf2-mediated antioxidant responses

Vascular dementia (VD) results from accumulated damage in the vascular system, which is characterized by progressive impairments in memory and cognition and is second only to Alzheimer's disease (AD) in prevalence among all types of dementia. In contrast to AD, there is no FDA-approved treatment for VD owing to its multiple etiologies. In this study, we investigated whether CZ-7, a new derivative of Claulansine F (Clau F) with verified neuroprotective activity in vitro, could ameliorate the cognitive impairment of rats with permanent occlusion of bilateral common carotid arteries (2VO) and its potential mechanisms of action. The 2VO rats were orally administered CZ-7 (10, 20, 40 mg/kg) from day 27 to day 53 post-surgery. Morris water maze tests conducted at day 48-51 revealed that CZ-7 administration significantly reduced the escape latency in 2VO rats. After the rats were sacrificed on day 53, morphological studies using Nissl and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining showed that administration of CZ-7 markedly attenuated the pathological changes in CA1-CA3 area of the hippocampus, including neuronal cell loss, nuclear shrinkage, and dark staining of neurons, and significantly decreased the chronic cerebral hypoperfusion-induced cell loss. Klüver-Barrera staining study revealed that CZ-7 administration significantly improved the white matter lesions. 8-OHdG and reactive oxygen species (ROS) immunofluorescent analyses showed that CZ-7 administration significantly decreased oxidative stress in CA1-CA3 area of the hippocampus. Finally, we found that the CZ-7-improved oxidative stress might be mediated via the Nrf2 pathway, evidenced by the double immunofluorescent staining of Nrf2 and the elevation of expression levels of oxidative stress proteins HO-1 and NQO1. In conclusion, CZ-7 has therapeutic potential for VD by alleviating oxidative stress injury through Nrf2-mediated antioxidant responses.