THE USE OF TRANSCRIPTIONAL FACTORS AS TARGETS AND AGENTS FOR CHEMOPREVENTION

转录因子是基因表达的关键调控因子。它是CL R 这些因素控制着许多基因的表达，因此 调节诸如“肿瘤促进剂”之类的生物效应。这个 本项目的目的是设计转录因子的突变体。 特别是为了抑制它们的生化反应，最重要的是， 它们的生物功能。 AP-1复合体被明确地牵涉到介导 肿瘤促进剂佛波酯的生物效应。一位少校 该复合体的成分是c-jun癌基因。我们已经创造了和 测试了一系列显性-负性c-jun突变体，这些突变体能够 抑制该癌基因的生化功能。一种激活 N端氨基酸2-122缺失的突变体已被 抑制AP-I反式激活和c-jun转化。在……里面 此外，该突变体已被证明通过以下方式抑制细胞转化 多种癌基因，包括c-fos、c-raf、ras、mos和myc。 此外，该突变蛋白在小鼠表皮细胞中稳定表达 能阻断佛波酯诱导的促癌作用，且水平较高 该蛋白的表达可抑制广泛的信号转导 多种生长因子。这个突变体的作用机制是 已被证明是异二聚化和中和 其他AP-1复杂成分，如c-fos。 我们最新的努力旨在进一步完善效力和 通过创建更小的突变体来获得这些突变体的特异性 二聚化和DNA结合的亲和力及其在特定条件下的测试 人类肿瘤系统，如乳腺癌和肺癌。我们现在有了 创建了一系列含有更大N端缺失的c-jun突变体 生产仅含亮氨酸拉链的小肽(二聚化 域)。此外，三个DNA结合突变体(一个)的效力 在第265位有点突变，在某些位置有缺失 269-272，在第265位插入3个氨基酸) 已经进行了分析，目前正在研究其作用机制 调查过了。 未来的努力旨在设计可能 使这些药物更适用于临床。体内测试将是 在使用转基因技术和啮齿动物的模型系统中进行 模型系统。最后，我们将扩大这些研究的范围，将其他 转录因子在人类致癌物质中发挥关键作用 以CREB的身份。

Transcription factors are critical regulators of gene expression. It is cl r that these factors control the expression of many genes and as such mediate the biologic effects of agents such as "tumor promoters." The purpose of this project is to design mutants of transcription factors specifically aimed at inhibiting their biochemical and, most importantly, their biologic functions. The AP-1 complex has been specifically implicated in mediating the biologic effects of the tumor promoters "phorbol esters." A major component of this complex is the c-jun oncogene. We have created and tested a series of dominant-negative mutants of c-jun that are able to inhibit the biochemical functions of this oncogene. A transactivation mutant with a deletion of the N-terminal amino acids 2-122 has been shown to inhibit AP-I transactivation and c-jun transformation. In addition, this mutant has been shown to inhibit cellular transformation by a wide range of oncogenes including c-fos, c-raf, ras, mos, and myc. Further, stable expression of this mutant protein in mouse epidermal cells can block phorbol ester induced tumor promotion, and high level expression of this protein can inhibit signal transduction from a wide variety of growth factors. The mechanism of action of this mutant has been demonstrated to be heterodimerization with and neutralization of other AP-1 complex components such as c-fos. Our most recent efforts are aimed at further refining the potency and specificity of these mutants by creating smaller mutants with higher affinities for dimerization and DNA binding and testing them in specific human tumor systems such as breast and lung cancers. We have now created a series of c-jun mutants containing larger N-terminal deletions producing small peptides containing only the leucine zipper (dimerization domain). In addition, the potency of three DNA binding mutants (one with a point mutation at position 265, one with a deletion at positions 269-272, and one with an insertion of 3 amino acids at position 265) have been analyzed, and the mechanisms of action are presently being investigated. Future efforts are aimed at designing delivery mechanisms that might make these agents more clinically applicable. In vivo testing will be performed in model systems using transgenic technology and rodent model systems. Finally, we will expand these studies to include other transcription factors which play critical roles in human carcinogens such as CREB.