TOBACCO-SPECIFIC NITROSAMINE: RIA FOR DNA-ADDUCTS

根据1982年外科医生的报告， 死于肺癌的可能性比不吸烟者高。 流行病学 研究表明鼻烟壶会增加口腔癌的风险。 据估计，美国有700万鼻烟壶， 数量增长迅速。 在过去的十年里，我们对 实验室和其他机构已经证明存在两种致癌物质， 烟草特有的N-亚硝胺、N '-亚硝基去甲尼古丁（NNN）和 4-（甲基亚硝胺基）-1-（3-吡啶基）-1-丁酮（NNK）。 NNN和NNK是 在香烟烟雾中的含量为0.11-3.7微克/支。 烟草特有 亚硝胺是唯一已知的大量分离的致癌物质 来自鼻烟（NNN和NNK为210- 33，000 ppb）。 动物研究 显示NNN和NNK是有效的致癌物，NNK是一种特别 强致癌物 NNN和NNK也显示出烷基化DNA。 为了进一步研究NNN和NNK暴露之间的关系， 以及烟草相关癌症的发展， 需要特定的DNA加合物。 由于敏感的免疫测定， 致癌物DNA加合物已经开发出来，这一研究的具体目的是 建议1）开发NNN和NNK-DNA特异性单克隆抗体 加合物，2）开发免疫印迹测定（使用这些单克隆抗体， 抗体）能够检测小样本中的低水平DNA加合物， 人DNA，和3）通过以下方式证明该测定的适用性： 测定DNA中烟草特异性亚硝胺DNA加合物的水平 从鼻烟壶的口腔粘膜中分离得到。 长期目标是 一项建议是制定足够敏感和简单的方法 它可以被临床化学家应用于大量的烟草 用户. 这可以让检测到那些风险增加的人 与烟草有关的癌症

According to the 1982 report of the Surgeon General smokers are 10 times more likely to die from lung cancer than are non-smokers. Epidemiological studies have shown an increased risk of oral cancer in snuff-dippers. There are an estimated 7,000,000 snuff-dippers in the United States with the number growing rapidly. In the last decade extensive studies in our laboratory and others have demonstrated the presence of two carcinogenic tobacco specific N-nitrosamines, N'-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). NNN and NNK are present in cigarette smoke at 0.11-3.7 Mug/cigarette. Tobacco specific nitrosamines are the only known carcinogens isolated in significant amounts from snuff tobacco (210-33,000 ppb for NNN and NNK). Animal studies have shown NNN and NNK to be potent carcinogens and NNK to be a particularly potent lung carcinogen. NNN and NNK have also been shown to aklylate DNA. In order to study further the relationship between exposure to NNN and NNK and the development of tobacco related cancer, an assay for tobacco specific DNA adducts is needed. Since sensitive immunoassays for a number of carcinogen DNA adducts have been developed, the specific aims of this proposal are 1) develop monoclonal antibodies specific for NNN and NNK-DNA adducts, 2) develop an immunoblotting assay (using these monoclonal antibodies) able to detect low levels of DNA adducts in small samples of human DNA, and 3) demonstrate the applicability of this assay by determining the level of tobacco specific nitrosamine DNA adducts in DNA isolated from the oral mucosa of snuff-dippers. The long term goal of this proposal is to develop methodology of sufficient sensitivity and simplicity that it can be applied by clinical chemists to large numbers of tobacco users. This could allow detection of those individuals at increased risk of developing tobacco related cancer.