USE OF IMMUNOLOGICAL TECHNIQUES TO STUDY THE INTERACTION OF CARCINOGENS WITH DNA

针对致癌物-DNA加合物的抗体已经探索了这种性质， 体外和体内DNA修饰的程度和后果。DNA 取代为2-乙酰氨基荧烯(AAF)、苯并[a]芘(BP)或 对顺二胺二氯铂II(cis-DDP)进行了定量分析 免疫分析能够在1亿个核苷酸中检测到一个加合物， 通过开发免疫组织化学程序定位加合物在 SITE。在给予致癌剂量的AAF 4周的大鼠的肝DNA中， 加合物积累在2-3周时达到平台期，并显示加合物 免疫组织化学主要定位于门脉周围区域。 在随后4周的对照饮食中，加合物的去除是双相的。一个 与这一数据一致的计算机导出的药代动力学模型 加合物形成两个基因组隔间，其中一个来自 加合物被迅速去除，而另一种则被除去 慢慢地。与大鼠肝脏中形成的高水平的AAF加合物形成对比 DNA中，DNA中形成的加合物数量至少减少了50倍 小鼠表皮和培养的小鼠表皮细胞暴露于 剂量的BP。当两种致癌物的活化形式在 角质形成细胞焦点分析N-乙酰氧基-AAF每摩尔产生更多的加合物 浓度高于BP衍生物，但无分化改变灶 在N-乙氧基-AAF处理的培养中形成。有核外周血细胞 从癌症患者身上多次获得DNA，在 顺铂治疗，共分析223个样本。其中，23人 未经处理的对照样本呈阴性，来自中国的200个样本中有46% 接受顺铂治疗的患者均为阳性。加和累加，正数 患者，作为总累积剂量的函数发生，这表明 加合物去除相对较慢。47例患者的疾病反应数据 表明加合物水平大于200的个体 Attomoles/Mug DNA对以下疾病的完全应答率非常高(65%) 心理治疗。动物模型的平行实验已经证明， 在大鼠和小鼠的肾脏、性腺和肿瘤中存在相同的加合物形式 与剂量的关系。

Antibodies specific for carcinogen-DNA adducts have probed the nature, extent, and consequences of in vitro and in vivo DNA modification. DNAs substituted with 2-acetylaminofluorene (AAF), benzo[a]pyrene (BP), or cis-diamiminedichloro-platinum II (cis-DDP) were analyzed by quantitative immunoassays able to detect one adduct in one hundred million nucleotides, and by immunohistochemical procedures developed to localize adducts in situ. In hepatic DNA of rats fed a carcinogenic dose of AAF for 4 weeks, adduct accumulation reached a plateau at 2-3 weeks and adducts were shown by immunohistochemistry to be primarily localized in the periportal areas. During 4 subsequent weeks on control diet, adduct removal was biphasic. A computer-derived pharmacokinetic model consistent with this data proposed that adducts are formed into two genomic compartments, one from which adducts are removed rapidly and another from which they are removed slowly. In contrast to the high levels of AAF adducts formed in rat liver DNA, at least 50-fold lower adduct quantities were formed in the DNA of mouse epidermis and cultured mouse epidermal cells exposed to initiating doses of BP. When activated forms of both carinogens were utilized in the keratinocyte focus assay N-acetoxy-AAF yielded more adducts per molar concentration than the BP derivative but no differentiation-altered foci formed in N-acetoxy-AAF treated cultures. Nucleated peripheral blood cell DNA was obtained from cancer patients at multiple times during courses of cis-DDP therapy, and a total of 223 samples were analyzed. Of these, 23 untreated control samples were negative, and 46% of the 200 samples from patients receiving cis-DDP were positive. Adduct accumulation, in positive patients, occurred as a function of total cumulative dose, suggesting relatively slow adduct removal. Disease response data on 47 patients indicated that individuals with adduct levels greater than 200 attomoles/Mug DNA have a very high (65%) rate of complete response to therapy. Parallel experiments in animal models have demonstrated that the same adduct forms in kidney, gonads, and tumors of rats and mice in direct relation to dose.