title: DNA hypomethylation induced by drinking water disinfection by-products in mouse and rat kidney.
abstract: Bromodichloromethane (BDCM), chloroform, dibromoacetic acid (DBA), dichloroacetic acid (DCA), and trichloroacetic acid (TCA) are chlorine disinfection by-products (DBPs) found in drinking water that have indicated renal carcinogenic and/or tumor promoting activity. We have reported that the DBPs caused DNA hypomethylation in mouse liver, which correlated with their carcinogenic and tumor promoting activity. In this study, we determined their ability to cause renal DNA hypomethylation. B6C3F1 mice were administered DCA or TCA concurrently with/without chloroform in their drinking water for 7 days. In male, but not female mouse kidney, DCA, TCA, and to a lesser extent, chloroform decreased the methylation of DNA and the c-myc gene. Coadministering chloroform increased DCA but not TCA-induced DNA hypomethylation. DBA and BDCM caused renal DNA hypomethylation in both male B6C3F1 mice and Fischer 344 rats. We have reported that, in mouse liver, methionine prevented DCA- and TCA-induced hypomethylation of the c-myc gene. To determine whether it would also prevent hypomethylation in the kidneys, male mice were administered methionine in their diet concurrently with DCA or TCA in their drinking water. Methionine prevented both DCA- and TCA-induced hypomethylation of the c-myc gene. The ability of the DBPs to cause hypomethylation of DNA and of the c-myc gene correlated with their carcinogenic and tumor promoting activity in mouse and rat kidney, which should be taken into consideration as part of their risk assessment. That methionine prevents DCA- and TCA-induced hypomethylation of the c-myc gene would suggest it could prevent their carcinogenic activity in the kidney.
authors: Department of Internal Medicine, Division of Hematology and Oncology, College of Medicine and Public Health, The Ohio State University, Columbus, 43210, USA. tao-2@medctr.osu.edu
authors: Lianhui
authors: L
authors: Tao
authors: Wei
authors: W
authors: Wang
authors: Long
authors: L
authors: Li
authors: Paula K
authors: PK
authors: Kramer
authors: Michael A
authors: MA
authors: Pereira
mesh_terms: D000085:Acetates / Q000737:chemistry; D000818:Animals; D019175:DNA Methylation / Q000187:drug effects*; D003999:Dichloroacetic Acid / Q000737:chemistry; D004202:Disinfectants / Q000633:toxicity*; D005260:Female; D016259:Genes, myc / Q000235:genetics; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008715:Methionine / Q000494:pharmacology; D051379:Mice; D051381:Rats; D018570:Risk Assessment; D014238:Trichloroacetic Acid / Q000737:chemistry; D014881:Water Supply / Q000032:analysis*
chemical_list: D000085:Acetates; D004202:Disinfectants; D014238:Trichloroacetic Acid; C088674:dibromoacetic acid; D003999:Dichloroacetic Acid; D008715:Methionine