POLYCYCLIC HYDROCARBON METABOLISM AND CARCINOGENESIS

这项研究的总体目标是更好地理解 调节细胞色素P450IA1，即细胞色素P450IA1，以影响 多环烃(PAH)的致癌问题 如苯并(A)芘(B(A)P)和3-甲基胆菲(3mc)，因为它是 CyPIA1部分负责这些基因的激活 物质。这个实验室假定需要一种多环芳烃结合 蛋白，并分离、纯化和鉴定了一种4S蛋白 满足这一要求。我们最近确定4S多环芳烃- 结合蛋白与甘氨酸N-甲基转移酶(GNMT)相同。这个 本续订申请的具体目的是a)确定 B(A)P诱导的细胞色素PIA1表达中的4S PAH结合蛋白，以及 B)查明负面管制的潜在机制 大鼠细胞色素P450IA1基因，即细胞色素P450IA1。关于第一个问题 特异性靶基因转导对4S结合的影响 进入啮齿动物细胞的蛋白质将取决于CyPIA1的活性 (和合适的报告基因)在给予B(A)P后，效果 给药反义寡核苷酸(针对4S结合 蛋白质)和4S蛋白抗体的数量将根据 细胞暴露于苯并(A)P后对细胞色素PIA1的诱导作用 肝脏和肝癌细胞预先暴露于多环芳烃对4S水平的影响 结合蛋白及其信使核糖核酸将被确定。关于2号 特定的目的，在消极调控中发挥作用的顺式因素 将被定义为与之相互作用的反式作用蛋白 这些顺式元件将被分离和表征，并且 负调控元件与站点之间的沟通 4S结合蛋白的相互作用将被研究。

The overall objective of this research is to better understand the regulation of cytochrome P450IA1, i.e., CYPIA1, in order to impact upon the problem of carcinogenesis induced by polycyclic hydrocarbons (PAH) such as benzo(a)pyrene (B(a)P and 3-methylcholanthrene (3MC), since it is CYPIA1 that is responsible, in part, for the activation of these substances. This laboratory has postulated the need for a PAH-binding protein and has isolated, purified, and characterized a 4S protein that fulfills this requirement. We have recently established that the 4S PAH- binding protein is identical to glycine N-methyltransferase (GNMT). The specific aims of this renewal application are to a) determine the role of the 4S PAH-binding protein in the B(a)P-induced expression of CYPIA1, and b) to ascertain the mechanisms underlying the negative regulation of the rat cytochrome P450IA1 gene, i.e., CYPIA1. With regard to the first specific aim, the effect of transduction of the gene for the 4S binding protein into rodent cells will be determined upon the activity of CYPIA1 (and of suitable reporter genes) after administration of B(a)P, the effect of administration of antisense oligonucleotides (to the 4S binding protein) and of antibodies to the 4S protein will be determined upon induction of CYPIA1 after exposure of cells to B(a)P, and the effect of prior exposure of liver and hepatoma cells to PAH upon the level of the 4S binding protein and its mRNA will be ascertained. In regard to the 2nd specific aim, the cis elements that play a role in the negative regulation of CYPIA1 will be defined, the trans-acting proteins that interact with these cis elements will be isolated and characterized, and the communication between the negative regulatory element and the sites for interaction of the 4S binding protein will be investigated.