The DNA adductome of lung carcinogenesis

总结 肺癌是全球最常见的癌症，2012年死亡人数为160万，2013年死亡人数为158，000人。 2015年美国死亡人数尽管香烟烟雾在这一流行病中的作用很明显， 这种癌症是如何发展的还不清楚。尽管有反吸烟运动，2014年仍有40个 美国有100万烟民，全球有10亿多烟民。更有效的预防和治疗战略 这种疾病，需要更好的工具来了解肺癌病因和发展的机制。 许多研究表明，烟草烟雾中存在的化学物质诱导DNA修饰（DNA 加合物），如果不修复，可能导致突变，最终导致正常细胞生长控制的丧失 机制和肺癌。这些研究中，许多使用相对非特异性的技术，如 免疫测定和32 P-后标记，已经清楚地表明，DNA加合物水平较高，在肺 吸烟者比不吸烟者多，这与吸烟者肺部发现的多个突变一致。 然而，使用这些非特异性技术并没有导致任何的正结构表征。 DNA加合物，并因此在一个明确的识别机制参与其形成。其他研究 针对特定的DNA加合物，导致了一些化学特征的DNA鉴定 加合物，但这些结果并不能解释那些发现使用更一般的非特异性的方法。精确 肺癌发生过程中DNA损伤的精确和全面的表征仍然存在， 难以捉摸我们开发了一种新的基于质谱的DNA内收体方法， 对DNA加合物进行全面的高分辨率分析，并提供有关其断裂的信息 允许结构解析。我们的长期目标是确定DNA损伤特征 肺癌发生，以确定DNA内收酶，最终可用于早期检测预防， 治疗我们的假设是，与我们的方法将联合收割机的筛选能力的非特异性的方法 在过去使用的特定化学表征的各种修改检测，导致在一个 特定的内收肌侧貌。本申请的目的是：1.为了表征肺DNA内收酶， 烟草特异性亚硝胺NNK诱发肺癌动物模型的建立及加合物的鉴定 通过共同暴露于促炎剂脂多糖（LPS）来增强其作用; 2.到 描述这些模型中DNA内收体随时间的演变，阐明 炎症和内源性过程; 3.来表征吸烟者肺DNA中的DNA内收体 将其与非吸烟者和动物模型中鉴定的概况进行比较。我们的成果将 表征与NNK和NNK+LPS诱导的肺癌发生相关的内收体， 吸烟者肺DNA中的内收酶，为识别吸烟者的分子特征奠定了基础。 人类分子流行病学研究中的癌症病因学调查。 1

SUMMARY Lung cancer is the most common cancer worldwide, accounting for 1.6 million deaths in 2012 and for 158,000 deaths in the US in 2015. Despite the clear role of cigarette smoke in this epidemic, the precise mechanisms through which this cancer develops remain unclear. Despite anti-smoking campaigns, in 2014 there were still 40 million smokers in the U.S. and over 1 billion worldwide. More effective strategies for prevention and treatment of this disease, demand better tools to understand the mechanisms of lung cancer etiology and development. Numerous studies have shown that chemicals present in tobacco smoke induce DNA modifications (DNA adducts) which if not repaired, can lead to mutations ultimately resulting in loss of normal cellular growth control mechanisms and lung cancer. Many of these studies, using relatively non-specific techniques such as immunoassay and 32P-postlabelling, have clearly shown that DNA adduct levels are higher in the lungs of smokers than non-smokers, which is consistent with the multiple mutations found in the lungs of smokers. However, use of these non-specific techniques has not resulted in the positive structural characterization of any DNA adduct, and thus on a clear identification of the mechanisms involved in their formation. Other studies targeted at specific DNA adducts, have resulted in the identification of a few chemically characterized DNA adducts, but these results do not explain those found using the more general non-specific approaches. A precise characterization of the DNA damage during lung carcinogenesis that is both precise and comprehensive remains elusive. We have developed a new mass spectrometry based DNA adductomic approach performing comprehensive high resolution analysis of DNA adducts and providing information on their fragmentation allowing for structural elucidation. Our long-term goal is to determine the DNA damage profile characterizing lung carcinogenesis to identify a DNA adductome that may be ultimately used for early detection prevention and treatment. Our hypothesis is that with our method will combine the screening ability of the non-specific methods used in the past with the specific chemical characterization of the various modifications detected, resulting in a specific adductomic profile. The objectives of this application are: 1. to characterize the lung DNA adductome in animal models using the tobacco specific nitrosamine NNK to induce lung cancer and identify the driver adducts by enhancing its effects by co-exposure to the pro-inflammatory agent lipopolysaccharide (LPS); 2. to characterize the evolution of the DNA adductome in these models over time, clarifying the contribution of inflammation and endogenous processes; 3. to characterize the DNA adductome in smokers' lung DNA comparing it to non-smokers and to the profile identified in the animal models. Collectively our results will characterize the adductome associated with NNK and NNK+LPS induced lung carcinogenesis and the adductome in the lung DNA of smokers, setting the stage for the identification of molecular signatures for the investigation of cancer etiology in human molecular epidemiology studies. 1