DOMINANT NEGATIVE ESTROGEN RECEPTORS AND BREAST CANCER

这项研究的目的是开发和研究一种新颖的 雌激素受体（ER）功能失活的方法 雌激素反应性人类乳腺癌细胞。该方法基于 显性失活 ER 突变体，虽然其自身不活跃， 当野生型 ER 共表达于 相同的细胞。通过替换 N- 将会产生强大的 ER 突变体 和带有聚丙氨酸束的 C 端反式激活结构域 使用 P22 挑战噬菌体系统来分离导致 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，并干扰 ER- 特定转录成分对显性活性的影响 将确定阴性突变体。稳定转染的 MCF-7 人 产生显性失活突变 ER 的乳腺癌细胞将 在体外检查雌激素刺激生长的抑制作用，并在 体内使用无胸腺裸鼠。这些研究将提供新的见解 内质网对基因表达和增殖的调节 乳腺癌细胞的致瘤性，并允许评估新的 消除雌激素依赖性乳腺癌生长的方法。

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.