DNA adductome of human bladder from the tobacco exposome

摘要 烟草烟雾中的70多种化学物质是致癌物质。吸烟是膀胱癌的危险因素； 然而，尽管经过多年的研究，烟草烟雾和环境中破坏环境的主要化学物质 膀胱的DNA尚不清楚。芳香胺(AAs)和杂环芳胺(HAAs)存在于 烟草烟雾，并对吸烟者尿液中的大部分致突变性负责。一些AA(可能还有 HAAs)是膀胱癌的致癌物，也会诱发啮齿类动物的肝癌、膀胱癌和结直肠癌，而且很可能 导致人类患上这些癌症。4-氨基联苯(4-ABP)是一种人类膀胱癌物质；然而， 几种烷基苯胺和结构上相关的卤代烃在烟草烟雾中的含量高达100倍以上 4-ABP。一些流行病学研究将N-亚硝基化合物和多环芳烃联系在一起 作为膀胱癌的危险因素。对DNA加合物的稳健测量对于理解 烟草烟雾、环境和饮食中的化学物质会损害膀胱，并可能导致膀胱癌。 除了4-ABP，烟草烟雾中损害膀胱DNA的化学物质尚不清楚。的目标是 这一应用是应用稳健的筛选工具来鉴定来自外源和 破坏膀胱DNA的内源性来源。我们将采用我们最新开发的质谱仪(MS) 用于识别烟草烟雾冷凝物中形成DNA加合物的主要化学物质的吸合工具 吸烟者的膀胱。在目标1中，我们将使用香烟烟雾提取物(CSE)和人类膀胱进行研究 单独培养或与肝细胞共同培养细胞以评估肝脏代谢在肝细胞DNA损伤中的作用 膀胱。在带有CSE的膀胱细胞中形成的DNA加合物小组将作为指南，促进 吸烟者和非吸烟者膀胱尿路上皮DNA加合物组的特征 AIM中的癌症手术2.CSE中的一些前致癌物可以到达膀胱并通过以下方式进行生物激活 P450在膀胱中表达，尤其是芳香胺和HAAs。因此，在目标3中，我们将研究 用新型质谱仪检测参加戒烟研究的吸烟者尿中AAs和HAAs的含量 标记方法测量尿液中这些潜在的膀胱癌致癌物的总量，并评估其容量 来激活这些化合物。 我们的研究与美国国立卫生研究院的公共卫生使命有关。我们的研究将使我们更好地了解 烟草中的基因毒物会使环境产生烟雾，破坏膀胱DNA并导致膀胱癌。 通过将化学暴露和DNA加合物与突变数据合并，关于 环境、饮食和内源性基因毒物可以用来确定膀胱癌的高危人群。 一旦确定，就可以采取务实的措施，通过生活的变化来减少人类接触化学品- 减少环境暴露，这可能是最有效的化学预防手段。

Summary More than 70 chemicals in tobacco smoke are carcinogens. Tobacco smoking is a risk factor for bladder cancer; however, despite many years of study, the principal chemicals in tobacco smoke and environment that damage DNA of the bladder are unknown. Aromatic amines (AAs) and heterocyclic aromatic amines (HAAs) arise in tobacco smoke and are responsible for much of the mutagenicity in urine of smokers. Some AAs (and possibly HAAs) are bladder carcinogens, and also induce liver, bladder, and colorectal cancer in rodents, and likely contribute to these cancers in humans. 4-Aminobiphenyl (4-ABP) is a human bladder carcinogen; however, several alkylanilines and structurally related HAAs occur in tobacco smoke at levels up to 100-fold greater than 4-ABP. Some epidemiological studies have linked N-nitroso compounds and polycyclic aromatic hydrocarbons as risk factors for bladder cancer. Robust measurements of DNA adducts are important to understand the chemicals in tobacco smoke, the environment, and diet that damage the bladder and may contribute to bladder cancer. Apart from 4-ABP, the chemicals in tobacco smoke that damage bladder DNA are unknown. The objective of this application is to apply robust screening tools to identify DNA adducts derived from exogenous and endogenous sources that damage bladder DNA. We will employ our newly developed mass spectrometry (MS) adductomic tools to identify the major chemicals in tobacco smoke condensate that form DNA adducts in the bladder of smokers. In Aim 1, we will conduct studies with cigarette smoke extract (CSE) and human bladder cells incubated alone or in co-culture with hepatocytes to assess the role of liver metabolism in DNA damage of the bladder. The panel of DNA adducts formed in bladder cells with CSE will serve as a guide to facilitate the characterization of the DNA adductome of the urothelium of smokers and nonsmokers undergoing bladder cancer surgery in Aim 2. Some procarcinogens in CSE can reach the bladder and undergo bioactivation by P450s expressed in the bladder, particularly aromatic amines and HAAs. Therefore, in Aim 3, we will examine the urinary exposome of AAs and HAAs in smokers participating in a tobacco cessation study by novel mass- tagging methods to measure the totality of these potential bladder carcinogens in urine, and assess the capacity of bladder enzymes to bioactivate these compounds. Our research is relevant to NIH's mission on public health. Our studies will provide a greater understanding about genotoxicants in tobacco smoke the environment that damage bladder DNA and contribute to bladder cancer. By merging chemical exposures and DNA adducts with mutational data, clues about the identities of environmental, dietary and endogenous genotoxicants can be established to identify subjects at risk for bladder cancer. Once identified, pragmatic measures can be taken to reduce human exposure to chemicals, by changes in life- style or mitigation of environmental exposures, which are probably the most efficient means of chemoprevention.