Association between methylation of DNA damage response-related genes and DNA damage in hepatocytes of rats following subchronic exposure to vinyl chloride.

Abstract

In the present study, we investigated the association between methylation of DNA damage response-related genes such as cyclin-dependent kinase inhibitor (CDKN)2A, Ras association (RalGDS/AF-6) domain family member (RASSF)1A, O6-methylguanine DNA methyltransferase (MGMT), Kirsten rat sarcoma viral oncogene homolog (KRAS), and spleen-associated tyrosine kinase (SYK) and DNA damage in hepatocytes of rats following subchronic exposure to vinyl chloride (VC). Sixty-four healthy rats were randomly divided into three VC exposure groups (5, 25, and 125 mg/kg) and an untreated negative control group (n = 16 each). VC was administered by intraperitoneal injection every other day for a total of three times a week. Eight randomly selected rats from each group were sacrificed at the end of 6 and 12 weeks, and liver tissue was harvested for the comet assay and for assessment of DNA methylation level and mRNA expression of related genes by PCR. Overall methylation levels in the genome of hepatocytes in VC-exposed rats were higher than those in the control group at 6 and 12 weeks (P < 0.05), although no differences were observed with regarding to dose (P > 0.05). After 12 weeks of exposure, differences in the methylation of RASSF1A and MGMT promoter regions were observed between the high-dose group and other groups (P < 0.05), whereas no differences were observed for the KRAS, SYK, and CDKN2A promoters (P > 0.05). These results suggest that DNA damage and increased genome-wide methylation are biomarkers for VC exposure and that RASSF1A and MGMT promoter methylation is related to the carcinogenic mechanism of VC.

• Authors: Yu-Lan Qiu, Zhi-Bin Xu, Qian Wang, Jun-Yang Hu, Lin Zhang, Shi-Qi Chen, Yi Lyu, Cai-Ling Wei, Xiao-Yan Yan, Tong Wang
• Journal: Chemosphere (Chemosphere) Vol. 227 Pg. 323-328 (Jul 2019) ISSN: 1879-1298 [Electronic] England
• PMID: 30999172 (Publication Type: Journal Article)
• Copyright: Copyright © 2019 Elsevier Ltd. All rights reserved.

Chemical References

• RASSF1 protein, rat
• Tumor Suppressor Proteins
• DNA Modification Methylases
• Vinyl Chloride

Topics

• Animals
• DNA Damage (genetics)
• DNA Methylation (drug effects, genetics)
• DNA Modification Methylases (genetics)
• Dose-Response Relationship, Drug
• Hepatocytes (drug effects, metabolism)
• Humans
• Liver (metabolism, pathology)
• Promoter Regions, Genetic (drug effects)
• Rats
• Tumor Suppressor Proteins (genetics)
• Vinyl Chloride (toxicity)