Tamoxifen and Fulvestrant Hybrids Showed Potency as Selective Estrogen Receptor Down-Regulators
作者:Takuji Shoda、Masashi Kato、Takuma Fujisato、Yosuke Demizu、Hideshi Inoue、Mikihiko Naito、Masaaki Kurihara
DOI:10.2174/1573406412666160805101408
日期:2017.4.10
Background: Estrogen receptors (ERs) are an important target for the management of
breast cancers. Selective estrogen receptor down-regulators (SERDs) block ER activity, as well as
reduce ERα protein levels in cells, and therefore are promising therapeutic agents for the treatment
of breast cancers.
Objective: In order to develop potent SERDs, we prepared tamoxifen and fulvestrant hybrids and
evaluated their binding activity and down-regulation of ERα.
Methods: We designed and synthesized tamoxifen derivatives, which had a 4,4,5,5,5-
pentafluoropentyl group on the terminal alkyl chain. The oxidation state of the sulfur atom and alkyl
length between the sulfur and nitrogen atoms were varied. Western blotting was performed to determine
the ability to down-regulate ERα. Binding affinities of synthesized compounds were evaluated
by a fluorescence polarization-based competitive binding assay.
Results: We successfully prepared nine compounds. Treatment with 11, 14, and 17 effectively reduced
ERα protein levels in MCF-7 cells in a concentration-dependent manner. This reduction was
inhibited by a proteasome inhibitor. The ability of 14 to down-regulate the ERα protein level was
equal to fulvestrant. All compounds showed a largely equal affinity for ERα.
Conclusion: As indicated by Western blots, the ERα degradation activity was observed only in the
series of butyl linker derivatives, namely, 11, 14, and 17. These findings suggest that the specific
length of the alkyl chain is an important factor in controlling the down-regulation of ER. These results
provide useful information for designing promising SERD candidates.
背景:雌激素受体(ER)是治疗乳腺癌的重要靶点:雌激素受体(ER)是治疗乳腺癌的重要靶点。选择性雌激素受体下调剂(SERDs)能阻断ER的活性,降低细胞中ERα蛋白的水平,因此是治疗乳腺癌很有前景的治疗药物。 目的:为了开发强效的SERDs,我们制备了他莫昔芬和氟维司群混合物,并评估了它们的结合力和下调作用:为了开发强效的 SERDs,我们制备了他莫昔芬和氟维司群混合物,并评估了它们的结合活性和对 ERα 的下调作用。 方法:我们设计并合成了他莫昔芬和氟维司群混合物:我们设计并合成了他莫昔芬衍生物,这些衍生物的末端烷基链上含有4,4,5,5,5-五氟戊基。硫原子的氧化状态以及硫原子和氮原子之间的烷基长度各不相同。通过 Western 印迹法测定其下调 ERα 的能力。通过基于荧光偏振的竞争性结合试验评估了合成化合物的结合亲和力。 结果:我们成功制备了九种化合物。用 11、14 和 17 处理 MCF-7 细胞,能以浓度依赖性方式有效降低 ERα 蛋白水平。蛋白酶体抑制剂抑制了这种降低作用。14 下调 ERα 蛋白水平的能力与氟维司群相当。所有化合物对ERα的亲和力基本相同。 结论:正如 Western 印迹所示,只有丁基连接体衍生物系列(即 11、14 和 17)具有降解 ERα 的活性。这些发现表明,烷基链的特定长度是控制ER下调的一个重要因素。这些结果为设计有前途的 SERD 候选物提供了有用的信息。