Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy , University of Illinois at Chicago , 833 S. Wood St. , Chicago , Illinois 60612 , United States.
Department of Physiology and Biophysics, College of Medicine , University of Illinois at Chicago , 1835 W Polk St , Chicago , Illinois 60612 , United States.
ACS Chem Biol. 2018 Mar 16;13(3):676-684. doi: 10.1021/acschembio.7b01016. Epub 2018 Jan 24.
We and others have proposed that coactivator binding inhibitors, which block the interaction of estrogen receptor and steroid receptor coactivators, may represent a potential class of new breast cancer therapeutics. The development of coactivator binding inhibitors has been limited, however, because many of the current molecules which are active in in vitro and biochemical assays are not active in cell-based assays. Our goal in this work was to prepare a coactivator binding inhibitor active in cellular models of breast cancer. To accomplish this, we used molecular dynamics simulations to convert a high-affinity stapled peptide with poor cell permeability into R4K1, a cell-penetrating stapled peptide. R4K1 displays high binding affinity for estrogen receptor α, inhibits the formation of estrogen receptor/coactivator complexes, and distributes throughout the cell with a high percentage of nuclear localization. R4K1 represses native gene transcription mediated by estrogen receptor α and inhibits proliferation of estradiol-stimulated MCF-7 cells. Using RNA-Seq, we demonstrate that almost all of the effects of R4K1 on global gene transcription are estrogen-receptor-associated. This chemical probe provides a significant proof-of-concept for preparing cell-permeable stapled peptide inhibitors of the estrogen receptor/coactivator interaction.
我们和其他人已经提出，共激活因子结合抑制剂可以阻断雌激素受体和甾体受体共激活因子的相互作用，可能代表一类新的乳腺癌治疗药物。然而，由于许多目前在体外和生化测定中具有活性的分子在基于细胞的测定中没有活性，因此共激活因子结合抑制剂的开发受到限制。我们在这项工作中的目标是制备一种在乳腺癌细胞模型中具有活性的共激活因子结合抑制剂。为了实现这一目标，我们使用分子动力学模拟将一种具有高亲和力但细胞通透性差的订书肽转化为 R4K1，这是一种具有细胞穿透性的订书肽。R4K1 与雌激素受体 α 具有高结合亲和力，抑制雌激素受体/共激活因子复合物的形成，并在细胞内分布，具有高比例的核定位。R4K1 抑制由雌激素受体 α 介导的天然基因转录，并抑制雌二醇刺激的 MCF-7 细胞的增殖。通过 RNA-Seq，我们证明 R4K1 对全局基因转录的几乎所有影响都与雌激素受体相关。这种化学探针为制备细胞通透性的雌激素受体/共激活因子相互作用的订书肽抑制剂提供了重要的概念验证。
