The alternation of halobenzoquinone disinfection byproduct on toxicogenomics of DNA damage and repair in uroepithelial cells.

Halobenzoquinones (HBQs) were recently discovered as an emerging class of drinking water disinfection byproducts with carcinogenic concern. However, the molecular mechanism underlying HBQs-induced DNA damage is not clear. In this study, we integrated in vitro genotoxicity, computational toxicology, and the quantitative toxicogenomic analysis of HBQs on DNA damage/repair pathways in human bladder epithelial cells SV-HUC-1. The results showed that HBQs could induce cytotoxicity with the descending order as 2,6-DIBQ > 2,6-DCBQ ≈ 2,6-DBBQ. Also, HBQs can increase DNA damage in SV-HUC-1 cells and thus generate genotoxicity. However, there is no significant difference in genotoxicity among the three HBQs. The results of molecular docking and molecular dynamics simulation further confirmed that HBQs had high binding fractions and stability to DNA. Toxicogenomic analysis indicated that HBQs interfered with DNA repair pathways, mainly affecting base excision repair, nucleotide excision repair and homologous recombination repair. These results have provided new insights into the underlying molecular mechanisms of HBQs-induced DNA damage, and contributed to the understanding of the relationship between exposure to DBPs and risks of developing bladder cancer.

Rapid adaptation effect of N170 for printed words.

Faces and written words are two of the most familiar types of visual patterns with the brain's selective response of N170 component in early perception. Using ERP adaptation paradigms, studies have found the N170 response is reduced when there is repeated presentation of upright faces relative to a control condition. In contrast to these well-established features of the face-related N170 adaptation effect, the characteristics of the N170 adaptation effect for printed words are less clear. The goal was to investigate the ERP adaptation effects of printed language (English words and Chinese characters) in a short ISI (200 msec.) adaptation paradigm. The present study showed that both alphabetic words and non-alphabetic words could produce a rapid N170 adaptation effect. Objects of expertise (e.g. words and faces) can produce a rapid N170 adaptation effect but other objects (e.g., houses) cannot, indicating that the specific stimuli have some specific mechanisms for the rapid N170 adaptation.