MUTAGENIC CONSEQUENCES OF BENZO-A-PYRENE ADDUCTS

为了了解多环芳烃 碳氢化合物，如苯并（a）芘（BP），能够诱导 突变，必须回答三个问题。 (1)什么加合物 引发什么突变 (2)这些加合物是如何诱导这些 突变（即，直接或作为中间体）？ (3)为什么这些 加合物会诱发突变吗 中描述的工作 这一建议主要集中于回答第一个问题， 对于衍生的N2-鸟嘌呤、N（7）-鸟嘌呤和N6-腺嘌呤加合物 从多环芳烃。 形成的主要加合物 从体内BP（即，BP-N2-Gua）内置于双支架中， E.大肠杆菌，使用化学合成和 重组DNA技术。 修复改造后 熟练和修复缺陷E.大肠杆菌细胞，没有突变体 发现从BP-N2-Gua病变中产生， 百分之一 构建了一个新的载体，并将BP-N2-Gua构建到 将其制成单链并转化为E. coli细胞。 的 BP-N2-Gua衍生突变体的研究正在进行中。 通过类似 方法将BP-N2-Gua构建到穿梭载体中，和 转染到人类细胞中，以研究 这是人类细胞损伤的后果。 腺嘌呤加合物 似乎在致癌基因的诱变激活中起重要作用。 本文报道了7-溴甲基-12-N_6-腺嘌呤加合物 甲基苯并（a）蒽（BrMBA）将被构建成一种相关的病毒， 载体及其致突变作用的研究。coli细胞。 BPDE的N（7）-瓜尔豆加合物是化学不稳定的， 可能排除了它们被整合到利用 重组DNA和化学合成技术。 一个 研究诱变后果的替代方法 提出了不稳定的加合物。

To understand the machanism by which polycyclic aromatic hydrocarbons, such as benzo(a)pyrene (BP), are able to induce mutations, three questions must be answered. (1) What adducts induce what mutations? (2) How do these adducts induce these mutations (i.e., directly or as intermediates)? (3) Why do these adducts induce the mutations that they do? The work described in this proposal is primarily focused on answering the first question for N2-Guanine, N(7)-Guanine and N6-Adenine adducts derived from polycyclic aromatic hydrocarbons. The major adduct formed from BP in vivo (i.e., BP-N2-Gua) was built into a double standed, E. coli, viral vector using a combination of chemical synthetic and recombinant DNA techiques. Following transformation of repair proficient and repair deficient E. coli cells, no mutants were found to have arisen from the BP-N2-Gua lesion at the level of 1%. A new vector was constructed and BP-N2-Gua was built into it, made single stranded and transformed into E. coli cells. The search for BP-N2-Gua derived mutants is in progress. By similar methods BP-N2-Gua will be built into a shuttle vector, and transfected into human cells in order to study the mutagenic consequences of this lesion in human cells. Adenine adducts appear to be important in the mutagenic activation of oncogenes. The N6-Adenine adduct of 7-bromomethy1-12- methylbenz(a)antracene (BrMBA) will be built into a related viral vector and its mutagenic consequences studied in E. coli cells. N(7)-Gua adducts of BPDE are chemically unstable, which probably precludes their incorporation into vectors utilizing recombinant DNA and chemical synthetic techniques. An alternative method for studying the mutagenic consequences of unstable adducts is proposed.