RRC ID 72433
著者 Kobayashi T, Toyoda T, Tajima Y, Kishimoto S, Tsunematsu Y, Sato M, Matsushita K, Yamada T, Shimamura Y, Masuda S, Ochiai M, Ogawa K, Watanabe K, Takamura-Enya T, Totsuka Y, Wakabayashi K, Miyoshi N.
タイトル o-Anisidine Dimer, 2-Methoxy-N4-(2-methoxyphenyl) Benzene-1,4-diamine, in Rat Urine Associated with Urinary bladder Carcinogenesis.
ジャーナル Chem Res Toxicol
Abstract Monocyclic aromatic amines, o-toluidine (o-Tol) and its structural analog o-anisidine (o-Ans), are IARC Group 1 and Group 2A urinary bladder carcinogens, respectively, and are involved in metabolic activation and DNA damage. Our recent study revealed that 2-methyl-N4-(2-methylphenyl) benzene-1,4-diamine (MMBD), a p-semidine-type homodimer of o-Tol, was detected and identified in an in vitro reaction of o-Tol with S9 mix and in vivo urinary samples of o-Tol-exposed rats. Potent mutagenic, genotoxic, and cytotoxic activities were reported with MMBD, suggesting its involvement in urinary bladder carcinogenesis. However, it remains unknown whether o-Ans is converted to active metabolites to induce DNA damage in a similar manner as o-Tol. In this study, we report that a novel o-Ans metabolite, 2-methoxy-N4-(2-methoxyphenyl) benzene-1,4-diamine (MxMxBD), a dimer by head-to-tail binding (p-semidine form), was for the first time identified in o-Ans-exposed rat urine. MxMxBD induced a stronger mutagenicity in N-acetyltransferase overexpressed Salmonella typhimurium strains and potent genotoxicity and cytotoxicity in human bladder carcinoma T24 cells compared with o-Ans. These results suggest that MxMxBD may to some extent contribute toward urinary bladder carcinogenesis. In addition to homodimerization, such as MxMxBD, heterodimerizations were observed when o-Ans was coincubated with o-Tol or aniline (Ani) in in vitro reactions with S9 mix. This study highlights the important consideration of homodimerizations and heterodimerizations of monocyclic aromatic amines, including o-Ans, o-Tol, and Ani, in the evaluation of the combined exposure risk of bladder carcinogenesis.
巻・号 34(3)
ページ 912-919
公開日 2021-3-15
DOI 10.1021/acs.chemrestox.0c00536
PMID 33587850
MeSH Animals Carcinogens / chemistry Carcinogens / toxicity* Male Molecular Structure Mutagenicity Tests* Rats Rats, Inbred F344 Urinary Bladder Neoplasms / chemically induced*
IF 3.184
リソース情報
ヒト・動物細胞 T24(RCB2536)