METABOLIC ACTIVATION OF 2,6-DIMETHYLANILINE: MUTATIONAL SPECIFICITY IN THE GPT GENE OF AS52 CELLS
DOI:
https://doi.org/10.22159/ajpcr.2018.v11i9.27819Keywords:
2, 6-Dimethylaniline, Metabolic activation, Genotoxicity, AS52guanine phosphoribosyl transferase assayAbstract
Objective: The purpose of the current work was to characterize the mechanisms of cytotoxicity and mutagenesis of a potential human bladder carcinogen 2,6-dimethylaniline (2,6-DMA).
Methods: Chinese hamster ovary (CHO) AS52 cells were exposed to either human S9 activated 2,6-DMA for 6 h or its N-hydroxylamine and aminophenol metabolites for 1 h in serum-free medium. Cell survival was determined by trypan blue exclusion 24 h after treatment, and 6-thioguanine-resistant mutants at the xanthine-guanine phosphoribosyl transferase (gpt) gene locus were assessed with doses, of which relative survival is 30% or more. Nested polymerase chain reaction-based deletion analysis was also performed.
Results: AS52 cells exhibited a dose-dependent increase in cytotoxicity and mutant fraction on treatment of 2,6-DMA and its metabolites but show a considerable variation in potency with aminophenol metabolites having the highest potency and parent compound at least; at the highest 2,6-dimethylaminophenol dose (10 μM), the mutant fraction in AS52 cells was 8-fold (13.2×10−5) greater than the spontaneous fraction of 1.62×10−5. Total deletion of the gpt gene sequences was found in 1 (4%) spontaneous and 2 (6%) the 6-thioguanine mutants generated by N-hydroxy-2,6-DMA.
Conclusions: These findings indicate the mutagenicity of 2,6-DMA at the gpt gene, which is mediated through hydroxylamine and aminophenol metabolites, and contribute to the elucidation of mechanisms through which 2,6-DMA may exert its effects in vivo.
Downloads
References
2,6-dimethylaniline (2,6-xylidine). IARC Monogr Eval Carcinog Risks Hum 1993;57:323-35.
Matilde Marques M, Gamboa da Costa G, Blankenship LR, Culp SJ, Beland FA. The effect of deuterium and fluorine substitution upon the mutagenicity of N-hydroxy-2,6-dimethylaniline. Mutat Res 2002;506 507:41-8.
Luceri F, Pieraccini G, Moneti G, Dolara P. Primary aromatic amines from side-stream cigarette smoke are common contaminants of indoor air. Toxicol Ind Health 1993;9:405-13.
Palmiotto G, Pieraccini G, Moneti G, Dolara P. Determination of the levels of aromatic amines in indoor and outdoor air in Italy. Chemosphere 2001;43:355-61.
Cohen SM, Johansson SL. Epidemiology and etiology of bladder cancer. Urol Clin North Am 1992;19:421-8.
Gan J, Skipper PL, Gago-Dominguez M, Arakawa K, Ross RK, Yu MC, et al. Alkylaniline-hemoglobin adducts and risk of non-smoking-related bladder cancer. J Natl Cancer Inst 2004;96:1425-31.
Skipper PL, Tannenbaum SR, Ross RK, Yu MC. Nonsmoking-related arylamine exposure and bladder cancer risk. Cancer Epidemiol Biomarkers Prev 2003;12:503-7.
IARC Working Group on the Evaluation of Carcinogenic Risks to Humans. Chemical agents and related occupations. IARC Monogr Eval Carcinog Risks Hum 2012;100:9-562.
Tao L, Day BW, Hu B, Xiang YB, Wang R, Stern MC, et al. Elevated 4-aminobiphenyl and 2,6-dimethylaniline hemoglobin adducts and increased risk of bladder cancer among lifelong nonsmokers-the shanghai bladder cancer study. Cancer Epidemiol Biomarkers Prev 2013;22:937-45.
Skipper PL, Kim MY, Sun HL, Wogan GN, Tannenbaum SR. Monocyclic aromatic amines as potential human carcinogens: Old is new again. Carcinogenesis 2010;31:50-8.
Skipper PL, Trudel LJ, Kensler TW, Groopman JD, Egner PA, Liberman RG, et al. DNA adduct formation by 2,6-dimethyl-, 3,5-dimethyl-, and 3-ethylaniline in vivo in mice. Chem Res Toxicol 2006;19:1086-90.
Chao MW, Kim MY, Ye W, Ge J, Trudel LJ, Belanger CL, et al. Genotoxicity of 2,6- and 3,5-dimethylaniline in cultured mammalian cells: The role of reactive oxygen species. Toxicol Sci 2012;130:48-59.
Damani LA. Oxidation at Nitrogen Centers. Metabolic Basis of Detoxication. New York, NY: Academic Press; 1982.
Nelson SD. Arylamines and arylamides: Oxidation mechanism. In: Anders MW, editor. Bioactivation of Foreign Compounds. Orlando, FL: Academic Press, Inc.; 1985.
Gan J, Skipper PL, Tannenbaum SR. Oxidation of 2,6-dimethylaniline by recombinant human cytochrome P450s and human liver microsomes. Chem Res Toxicol 2001;14:672-7.
Tindall KR, Stankowski LF Jr. Machanoff R, Hsie AW. Detection of deletion mutations in pSV2gpt-transformed cells. Mol Cell Biol 1984;4:1411-5.
Tindall KR, Stankowski LF Jr. Machanoff R, Hsie AW. Analyses of mutation in pSV2gpt-transformed CHO cells. Mutat Res 1986;160:121 31.
Sun JD, Bus JS. Comparison of covalent binding of 14C-aniline HCl in red blood cells, spleen and liver of rats. Pharmacologist 1980;22:247.
Simmon VF. In vitro mutagenicity assays of chemical carcinogens and related compounds with salmonella typhimurium. J Natl Cancer Inst 1979;62:893-9.
Parodi S, Pala M, Russo P, Zunino A, Balbi C, Albini A, et al. DNA damage in liver, kidney, bone marrow, and spleen of rats and mice treated with commercial and purified aniline as determined by alkaline elution assay and sister chromatid exchange induction. Cancer Res 1982;42:2277-83.
Wilmer JL, Kligerman AD, Erexson GL. Sister chromatid exchange induction and cell cycle inhibition by aniline and its metabolites in human fibroblasts. Env Mutagen 1981;3:627-38.
Marques MM, Mourato LL, Amorim MT, Santos MA, Melchior WB Jr. Beland FA, et al. Effect of substitution site upon the oxidation potentials of alkylanilines, the mutagenicities of N-hydroxyalkylanilines, and the conformations of alkylaniline-DNA adducts. Chem Res Toxicol 1997;10:1266-74.
Li CQ, Trudel LJ, Wogan GN. Nitric oxide-induced genotoxicity, mitochondrial damage, and apoptosis in human lymphoblastoid cells expressing wild-type and mutant p53. Proc Natl Acad Sci U S A 2002;99:10364-9.
Li CQ, Trudel LJ, Wogan GN. Genotoxicity, mitochondrial damage, and apoptosis in human lymphoblastoid cells exposed to peroxynitrite generated from SIN-1. Chem Res Toxicol 2002;15:527-35.
Nohmi T, Miyata R, Yoshikawa K, Nakadate M, Ishidate M Jr. Metabolic activation of 2,4-xylidine and its mutagenic metabolite. Biochem Pharmacol 1983;32:735-8.
Beland FA, Melchior WB Jr. Mourato LL, Santos MA, Marques MM. Arylamine-DNA adduct conformation in relation to mutagenesis. Mutat Res 1997;376:13-9.
Gupta M, Dahiya J, Marwaha RK, Dureja H. Therapies in cancer treatment: An overview. Int J Pharm Pharm Sci 2015;7:1-9.
Dave M, Daga A, Rawal R. Structural and functional analysis of AF-9 MLL oncogene fusion protein using homology modeling and stimulation based approach. Int J Pharm Pharm Sci 2015;7:155-61.
Ferguson LR, Turner PM, Hart DW, Tindall KR. Amsacrine-induced mutations in AS52 cells. Environ Mol Mutagen 1998;32:47-55.
Hutchinson F. Chemical changes induced in DNA by ionizing radiation. Prog Nucleic Acid Res Mol Biol 1985;32:115-54.
Published
How to Cite
Issue
Section
The publication is licensed under CC By and is open access. Copyright is with author and allowed to retain publishing rights without restrictions.
