THE USE OF TRANSCRIPTIONAL FACTORS AS TARGETS AND AGENTS FOR CHEMOPREVENTION

转录因子是基因表达的关键调节因子。是 很明显，这些因素控制着许多基因的表达，因此， 介导诸如"肿瘤促进剂"的药剂的生物效应。"那 本项目的目的是设计转录因子的突变体 专门针对抑制他们的生化，最重要的是， 其生物功能。 AP-1复合物特别涉及介导生物学过程， 肿瘤促进剂佛波醇酯的作用。"其中一个主要组成部分是 复合体是c-jun癌基因。我创造了一个又一个奇迹， C-JUN的显性负突变体能够抑制 这种致癌基因的生化功能。 一种反式激活突变体 N-末端氨基酸2 - 122的缺失已显示抑制AP-1 反式激活和c-jun转化。 此外，这种突变体还具有 已被证明可抑制多种癌基因引起的细胞转化 包括c-fos、c-raf、ras、mos和myc。此外，稳定表达 小鼠表皮细胞中的这种突变蛋白可以阻断佛波酯 诱导肿瘤促进。 该突变体的作用机制已被 证明与其他AP-1异源二聚化和中和 复杂的成分如c-fos。 我们最近的努力旨在进一步提高效力， 这些突变体的特异性，通过创建更小的突变体， 二聚化和DNA结合的亲和力，并在特定的 人类肿瘤系统，例如乳腺癌和肺癌。我们现在已经创建了一个 一系列含有较大N-末端缺失的c-jun突变体， 仅含亮氨酸拉链（二聚化结构域）的小肽。 此外，三个DNA结合突变体，包括一个点突变， 在位置265处的缺失，在位置269 - 272处的缺失，以及在位置269 - 272处的插入 在位置265处的3个氨基酸的氨基酸序列已经产生。 所有这些变种人 已被证明具有显性阴性表型。 今后的努力旨在设计交付机制， 这些药物更适用于临床。将进行体内试验 在模型系统中。最后，我们将扩大这些研究，包括其他 在人类肿瘤发生中起关键作用的转录因子 例如CREB。

Transcription factors are critical regulators of gene expression. It is clear 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 which 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-1 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. 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 furthering 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, three DNA binding mutants including one with a point mutation at position 265, a deletion at positions 269-272, and one with an insertion of 3 amino acids at position 265 have been produced. All of these mutants have been demonstrated to have a dominant-negative phenotype. Future efforts are aimed at designing delivery mechanisms which might make these agents more clinically applicable. In vivo testing will be performed in model systems. Finally, we will expand these studies to include other transcription factors which play critical roles in human carcinogenesis such as CREB.