Ubiquitin Protein Ligase Ring2 Is Involved in S-phase Checkpoint and DNA Damage in Cells Exposed to Benzo[a]pyrene

OGG1 methylation mediated the effects of cell cycle and oxidative DNA damage related to PAHs exposure in Chinese coke oven workers

Previous publications have indicated that polycyclic aromatic hydrocarbons (PAHs) exposures are associated with increased DNA damage and abnormal cell cycle arrest; however, the details of mechanisms remain largely unknown. This study aimed to quantify the associations of 8-oxoguanine DNA glycosylase (OGG1) methylation with urinary PAHs metabolites, DNA damage and cell cycle arrest, and further to assess the role of OGG1 methylation in mediating the association of urinary PAHs metabolites with DNA damage and cell cycle arrest. Urinary biomarkers of PAHs exposure and a marker of oxidative DNA damage (8-hydroxy-2'-deoxyguanosin, 8-OHdG) were measured by high performance liquid chromatography. Cell cycle of lymphocyte was analysed with flow cytometry and OGG1 methylation in venous blood was measured by pyrosequencing. After adjusting for covariates, urinary 1-OHP levels were positively associated with lymphocyte S phase arrest and oxidative DNA damage, while were negatively associated with G0/G1 phase arrest. OGG1 methylation was not only positively correlated with urinary 1-OHP in a dose-responsive manner (P trend = 0.008) but was also associated with G0/G1 phase arrest (OR: 0.63, 95% CI: 0.41-0.97), S phase arrest (OR: 1.55, 95% CI: 1.01-2.40) and oxidative DNA damage (OR: 1.71, 95% CI: 1.02-2.86). Mediation analysis estimated that OGG1 methylation mediated about 20% of associations between urinary 1-OHP levels and cell cycle arrest and oxidative DNA damage, respectively (all P < 0.05). Our findings suggested that urinary 1-OHP concentrations were associated with cell cycle arrest and oxidative DNA damage by a mechanism partly involving OGG1 methylation.

Effect of Benzo[a]pyrene-DNA Adduct in Cord Blood on the Neurodevelopment of 12-Month-Old Infants in Qingdao City

INTRODUCTION

The study was designed to explore the possible adverse effects of prenatal polycyclic aromatic hydrocarbons (PAHs) on the neurodevelopment of the infants at the age of 12 months in a birth cohort in Qingdao of China. Benzo[a]pyrene (BaP)-DNA adduct level in umbilical cord blood was measured by enzyme immunoassay.

METHODS

Child neurodevelopment was assessed at both 6 months and 12 months of age using the Gesell Development Inventory (GDI).

RESULTS

This study results reveal that multivariate linear analysis, cord BaP-DNA adduct level was inversely associated with developmental quotient score in the adaptive domain [β = -0.08; 95% CI: (-0.16, -0.003); p = 0.04], gross motor domain [β = -0.10; 95% CI: (-0.20, -0.01); p = 0.02], fine motor domain [β = -0.15; 95% CI: (-0.25, -0.05); p = 0.01], language domain [β = -0.12; 95% CI: (-0.21, -0.03); p = 0.02], and personal-social domain [β = -0.13; 95% CI: (-0.22, -0.04); p<0.01]. Further, multivariate logistic regression analysis showed increased cord BaP-DNA adduct levels associated with increased odds of delayed in language domain.

CONCLUSION

In conclusion, the study suggested that prenatal PAH exposure monitored by umbilical cord blood BaP-DNA adducts may adversely affect the neurodevelopment of the infants at 12 months of age.