Carcinogenic tobacco-specific nitrosamines induction of apurinic/apyrimidinic sites in DNA of human oral cells

项目摘要 在美国，吸烟是导致肺癌和口腔癌的主要原因。无烟烟草引发的原因 口腔、食道和胰腺癌。电子烟对健康的影响仍在调查中，但 可能会扰乱口腔动态平衡，导致肺部和心血管疾病。特定于烟草的 亚硝胺(4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone)和N‘-亚硝基烟碱(NNN)是 被国际癌症研究机构列为人类致癌物，并被公认为 这些疾病的原因。NNK和NNN的代谢激活导致反应性亲电物质的形成 修饰dna以生产各种产品，如N7-[4-(3-pyridyl)-4-oxobut-1-yl]-deoxyguanosine (N7POBdG)，可通过碱基的简单水解而在DNA中产生无嘌呤/无嘧啶(AP)位点- 脱氧核糖核苷键；其他烟草成分也可能诱发AP位点。AP站点积累可能 启动致癌过程。口腔细胞提供了吸烟和口腔癌之间的直接联系 在烟草使用者的口腔细胞中发现了高水平的DNA损伤。我们建议分析AP 口腔细胞DNA中具有两个特定目标的位点：建立一种高灵敏的质谱学方法来定量 人口腔细胞DNA中的AP位点，并对吸烟诱导的口腔细胞DNA中的AP位点进行定量，无烟 烟草和电子烟。目的是建立口腔细胞DNA AP位点作为烟草诱导的生物标记物 吸烟者、无烟烟草使用者和电子烟使用者的DNA损伤，并最终确定 为易受影响的烟草使用者制定预防癌症的有效策略。这项研究还可能提供 一项大型流行病学研究的初步数据。我们有强有力的初步数据支持这一提议。

Project Summary Cigarette smoking is the leading cause of lung and oral cancer in the United States. Smokeless tobacco causes cancer of the mouth, esophagus and pancreas. The health effects of e-cigarettes are still under investigation but may disturb oral cavity homeostasis and cause lung and cardiovascular diseases. The tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) are classified as human carcinogens by the International Agency for Research on Cancer, and are recognized causes of these diseases. Metabolic activation of NNK and NNN results in formation of reactive electrophiles that modify DNA to produce a variety of products such as N7-[4-(3-pyridyl)-4-oxobut-1-yl]-deoxyguanosine (N7POBdG) that can result in apurinic/apyrimidinic (AP) sites in DNA by facile hydrolysis of the base- deoxyribonucleoside bond; other tobacco constituents may also induce AP sites. AP site accumulation may initiate the carcinogenic process. Oral cells provide the direct link between tobacco use and oral cancer in humans and elevated DNA damage has been found in oral cells of tobacco users. We propose to analyze AP sites in oral cell DNA with two specific aims: to develop a highly sensitive mass spectrometric method to quantify AP sites in human oral cell DNA, and to quantify AP sites in oral cell DNA induced by cigarette smoke, smokeless tobacco and e-cigarettes. The goals are to establish oral cell DNA AP sites as biomarkers of tobacco induced DNA damage in cigarette smokers, smokeless tobacco users, and e-cigarette users, and to ultimately identify susceptible tobacco users and design effective strategies to prevent cancer. This study may also provide preliminary data for a large epidemiologic study. We have strong preliminary data to support this proposal.