Byrns Michael C, Vu Choua C, Neidigh Jonathan W, Abad José-Luis, Jones Roger A, Peterson Lisa A
Division of Environmental Health and Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Chem Res Toxicol. 2006 Mar;19(3):414-20. doi: 10.1021/tx050302k.
Furan is a toxic and carcinogenic compound used in industry and commonly found in the environment. The mechanism of furan's carcinogenesis is not well-understood and may involve both genotoxic and nongenotoxic pathways. Furan undergoes oxidation by cytochrome P450 to cis-2-butene-1,4-dial, which is thought to mediate furan's toxic effects. Consistently, cis-2-butene-1,4-dial readily reacts with glutathione, amino acids, and nucleosides. To determine the importance of DNA alkylation in furan-induced carcinogenesis, we developed an assay for the detection of cis-2-butene-1,4-dial-derived DNA adducts. DNA samples were treated with O-benzyl-hydroxylamine, which reacts with the aldehyde functionality of the DNA adducts. Enzyme hydrolysates of these samples were then analyzed by capillary electrospray tandem mass spectrometry with selected reaction monitoring. The dCyd and dAdo adducts were detected in digests of DNA treated with nanomolar concentrations of cis-2-butene-1,4-dial. In addition, these adducts were present in DNA isolated from Ames assay strain TA104 treated with mutagenic concentrations of cis-2-butene-1,4-dial. These data support the hypothesis that cis-butene-1,4-dial is a genotoxic metabolite of furan. This method will allow us to explore the role of these adducts in furan-induced carcinogenesis.
呋喃是一种有毒且具有致癌性的化合物，用于工业生产，在环境中也普遍存在。呋喃的致癌机制尚未完全明确，可能涉及基因毒性和非基因毒性途径。呋喃通过细胞色素P450氧化生成顺式-2-丁烯-1,4-二醛，据认为后者介导了呋喃的毒性作用。与此一致的是，顺式-2-丁烯-1,4-二醛能迅速与谷胱甘肽、氨基酸和核苷发生反应。为了确定DNA烷基化在呋喃诱导致癌过程中的重要性，我们开发了一种检测顺式-2-丁烯-1,4-二醛衍生的DNA加合物的方法。DNA样本用O-苄基羟胺处理，该物质与DNA加合物的醛官能团发生反应。然后，这些样本的酶水解产物通过毛细管电喷雾串联质谱结合选择反应监测进行分析。在用纳摩尔浓度的顺式-2-丁烯-1,4-二醛处理的DNA消化物中检测到了dCyd和dAdo加合物。此外，在用致突变浓度的顺式-2-丁烯-1,4-二醛处理的艾姆斯试验菌株TA104中分离得到的DNA中也存在这些加合物。这些数据支持了顺式-2-丁烯-1,4-二醛是呋喃的基因毒性代谢产物这一假说。该方法将使我们能够探索这些加合物在呋喃诱导致癌过程中的作用。
