CYP1A1 GENE REGULATION AND HUMAN CANCER

我们实验室的一个主要目标是阐明 人细胞色素P450、细胞色素P1A1与肺癌的关系蛋白质产品 CYP1A1基因及其相关的催化活性，包括芳基 (或芳香族)碳氢羟基酶(AHH)，已知与 与许多致癌原的代谢激活有关 香烟烟雾中发现的多环芳烃(PAHs) 将环境污染物转化为高活性中间体。升高的水平 在许多研究中都被认为是一种重要的 肺癌病因中的危险因素。我们的调查一直在进行 重点阐明了细胞色素P1A1基因表达的机制。 规范和建立偏差之间的函数关系 从正常的表达模式和肺癌。 A.我们对人CYP1A1基因表达调控的研究 利用寡核苷酸定向突变和报告基因在大肠杆菌中的表达 非小细胞肺癌来源的细胞系显示转录 该基因的激活是通过两个相距甚远的DNA介导的 监管要素。这种激活似乎是协同的，因为每个 大约只有30%的元件对基因的整体表达做出了贡献。 这些数据得到了蛋白质/DNA凝胶迁移率变化分析的支持 在控制和诱导条件下每个地点的相互作用。这部作品 代表了对监管要素进行表征的第一次努力 人类细胞色素P1A1基因的同源性及其在细胞周期调控中的作用 该基因在成人肺中的表达调控。 B.细胞色素P1A1基因表达的个体间变异可能是由于 编码细胞色素P1A1的基因内遗传差异的结果 转录调节蛋白。我们已经确认了至少两个 编码基因的限制性片段长度多态(RFLP) CYP1A1基因的主要转录激活因子--芳香族 碳氢(氢)受体。来自年龄、种族和性别的DNA与对照组和 经组织学证实的肺癌患者目前正在接受治疗 检查以确定这些新获得的基因的频率 两个种群内的标记。 这些项目的意义在于阐明了 遗传决定因素和化学致癌物在癌症中的作用 肺癌的发生。结果将具有诊断和预防作用 申请。

A major goal of our laboratory has been the elucidation of the role of the human cytochrome P450, CYP1A1, in lung carcinogenesis. The protein product of the CYP1A1 gene and its associated catalytic activities, including aryl (or aromatic) hydrocarbon hydroxylase (AHH), are known to be intimately associated with the metabolic activation of many of the procarcinogenic polycyclic aromatic hydrocarbons (PAHs) found in cigarette smoke and other environmental pollutants to highly reactive intermediates. Elevated levels of AHH activity have been implicated in numerous studies as a significant risk factor in the etiology of lung cancer. Our investigations have been focused upon elucidating the mechanisms by which CYP1A1 gene expression is regulated and to establish a functional relationship between deviations from normal patterns of expression and lung cancer. A. Our studies of the regulation of expression of the human CYP1A1 gene using oligonucleotide directed mutagenesis and reporter gene expression in non-small cell lung cancer derived cell lines reveal that transcriptional activation of the gene is mediated through two widely separated DNA regulatory elements. This activation appears to be synergistic, as each element contributes roughly only 30% to the overall expression of the gene. These data are supported by gel mobility shift analyses of protein/DNA interactions at each site under control and inducing conditions. This work represents the first effort at characterization of the regulatory elements of the human CYP1A1 gene and the determination of the role for each in the regulation of expression of the gene in the adult lung. B. Interindividual variability in CYP1A1 gene expression may arise as a result of genetic differences within the genes encoding CYP1A1 transcriptional regulatory proteins. We have identified at least two restriction fragment length polymorphisms (RFLPs) within the gene encoding the major transcriptional activator of the CYP1A1 gene, the aromatic hydrocarbon (Ah) receptor. DNA from age, race, and sex matched control and histologically confirmed lung cancer patients is presently under examination to determine the frequency of these newly acquired genetic markers within the two populations. The significance of these projects is the elucidation of the interactive role of genetically determined factors and chemical carcinogens in pulmonary carcinogenesis. The results will have diagnostic and prevention applications.