DNA adductome of human bladder from the tobacco exposome

总结 烟草烟雾中 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，烟草烟雾和环境中损害的主要化学物质 膀胱 DNA 未知。芳香胺（AA）和杂环芳香胺（HAAs）产生于 烟草烟雾是吸烟者尿液中大部分致突变性的原因。一些 AA（可能还有 HAAs）是膀胱致癌物，也会诱发啮齿类动物的肝癌、膀胱癌和结直肠癌，并且可能 导致人类这些癌症。 4-氨基联苯 (4-ABP) 是一种人类膀胱致癌物；然而， 烟草烟雾中存在多种烷基苯胺和结构相关的 HAA，其含量高达 100 倍。 4-ABP。一些流行病学研究已将 N-亚硝基化合物与多环芳烃联系起来 作为膀胱癌的危险因素。 DNA 加合物的稳健测量对于理解 DNA 加合物非常重要 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 4-ABP 外，烟草烟雾中损害膀胱 DNA 的化学物质尚不清楚。的目标 该应用旨在应用强大的筛选工具来识别源自外源和外源的 DNA 加合物。 损伤膀胱 DNA 的内源性来源。我们将采用我们新开发的质谱 (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加合物工具 吸烟者的膀胱。在目标 1 中，我们将利用香烟烟雾提取物 (CSE) 和人类膀胱进行研究 单独培养细胞或与肝细胞共培养，以评估肝脏代谢在 DNA 损伤中的作用 膀胱。用 CSE 在膀胱细胞中形成的 DNA 加合物组将作为指导，以促进 吸烟者和非吸烟者膀胱膀胱上皮 DNA 加合物的表征 目标 2 中的癌症手术。CSE 中的一些致癌物质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，特别是芳香胺和 HAA。因此，在目标 3 中，我们将研究 参与戒烟研究的吸烟者尿液中 AA 和 HAA 的暴露量 标记方法来测量尿液中这些潜在膀胱致癌物的总量，并评估其能力 膀胱酶来生物激活这些化合物。 我们的研究与 NIH 的公共卫生使命相关。我们的研究将提供更深入的了解 烟草烟雾环境中的遗传毒物会损害膀胱 DNA 并导致膀胱癌。 通过将化学暴露和 DNA 加合物与突变数据相结合，可以找到有关 可以建立环境、饮食和内源性遗传毒物来识别有膀胱癌风险的受试者。 一旦确定，就可以采取务实的措施，通过改变生活来减少人类对化学品的接触。 环境暴露的方式或缓解措施，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.