DOMINANT NEGATIVE ESTROGEN RECEPTORS AND BREAST CANCER

这项研究的目的是开发和调查一部小说 雌激素受体(ER)功能失活方法的研究 雌激素敏感的人类乳腺癌细胞。该方法的基础是 显性负性ER突变体，虽然本身不活跃， 抑制野生型内质网的活性 同样的细胞。强大的内质网突变体将通过取代N- 和带有聚丙氨酸束的C-末端反式激活结构域 使用P22挑战噬菌体系统分离导致 突变型ER竞争结合雌激素的能力增强 反应元件DNA。竞争的相对贡献 与ERE结合，形成异二聚体，干扰ER- 特定转录成分对活性具有显性作用 阴性突变者将被确定。稳定表达MCF-7的人 产生显性负突变ER的乳腺癌细胞将是 在体外检查雌激素刺激的生长抑制，并在 用裸鼠进行活体实验。这些研究将提供新的见解 内质网对基因表达和增殖的调控 乳腺癌细胞的致瘤性，并允许评估一种新的 消除雌激素依赖型乳腺癌生长的途径。

The objective of this research is to develop and investigate a novel method for functional inactivation of estrogen receptor (ER) in estrogen-responsive human breast cancer cells. The approach is based on dominant negative ER mutants which, while inactive on their own, suppress the activity of wildtype ER when they are co-expressed in the same cells. Powerful ER mutants will be generated by replacing the N- and C-terminal transactivation domains with polyalanine tracts and by using the P22 challenge phage system to isolate mutations that result in increased ability of mutant ER to compete for binding to estrogen response element DNA. The relative contributions of competition for binding to the ERE, formation of heterodimers, and interference with ER- specific transcription components to the activity of the dominant negative mutants will be determined. Stably transfected MCF-7 human breast cancer cells producing the dominant negative mutant ERs will be examined for suppression of estrogen-stimulated growth in vitro, and in vivo using athymic nude mice. These studies will provide new insights into ER regulation of gene expression and the proliferation and tumorigenicity of breast cancer cells, and allow evaluation of a novel approach for the extinction of estrogen-dependent breast cancer growth.