Macrocyclic Peptidyl Inhibitors of NEMO-IKK Interaction

项目摘要 NF-κB是一个转录因子家族，其在所有哺乳动物细胞类型中表达，并充当 免疫反应的主要调节者NF-κB的异常激活与 许多炎症和自身免疫性疾病以及癌症。NF-κB可被两种 不同的信号传导途径，经典（或经典）途径和非经典途径。 经典NF-κB信号通路涉及κB（IκB）-激酶α/β抑制剂之间的关键相互作用 (IKKα/β）和NEMO（也称为IKKγ）。因此，NEMO-IKKα/β相互作用的抑制代表了 由于抑制剂会阻断NF-κB活性，因此是一种有吸引力的抗炎和抗癌策略 诱导的促炎刺激，但不是基础的NF-κB活性，这是所需的正常B- 和T细胞功能。不幸的是，以前开发小分子抑制剂的尝试， 细胞内蛋白质-蛋白质相互作用在很大程度上是不成功。在这个项目中，我们将探索 用于抑制NEMO-IKKα/β相互作用的细胞渗透性大环肽。具体目标1是 为了进一步优化双环肽基抑制剂的效力、选择性和其它药物性质 （NI 174 -5; IC 50 = 1.0 µM），在我们的初步研究中发现， 并在结构上（通过X射线晶体学和计算机模拟）表征改进的NEMO 抑制剂。具体目的2是确定NI 174 -5（或改进的NEMO抑制剂）对 卵巢癌干细胞（CSC）在体外和体内，以及其防止肿瘤复发的能力 在原位卵巢肿瘤异种移植模型中初始顺铂治疗后。

Project Summary NF-κB is a family of transcription factors that are expressed in all mammalian cell types and act as the master regulator of the immune response. Aberrant activation of NF-κB has been implicated in many inflammatory and autoimmune diseases, as well as cancer. NF-κB can be activated by two different signaling pathways, the canonical (or classical) pathway and the non-canonical pathway. Canonical NF-κB signaling involves a key interaction between inhibitor of κB (IκB)-kinase α/β (IKKα/β) and NEMO (also called IKKγ). Inhibition of the NEMO-IKKα/β interaction thus represents an attractive anti-inflammatory and anticancer strategy, as the inhibitor would block the NF-κB activity induced by pro-inflammatory stimuli but not the basal NF-κB activity, which is required for normal B- and T-cell function. Unfortunately, previous attempts to develop small-molecule inhibitors against this intracellular protein-protein interaction have been largely unsuccessful. In this project, we will explore cell-permeable macrocyclic peptides for inhibition of the NEMO-IKKα/β interaction. Specific Aim 1 is to further optimize the potency, selectivity, and other drug properties of a bicyclic peptidyl inhibitor (NI174-5; IC50 = 1.0 µM) discovered during our preliminary studies and biochemically, biologically, and structurally (by X-ray crystallography and in silico modeling) characterize the improved NEMO inhibitor(s). Specific Aim 2 is to determine the effect of NI174-5 (or an improved NEMO inhibitor) on ovarian cancer stem cells (CSC) in vitro and in vivo, as well as its ability to prevent tumor relapse following initial cisplatin treatment in an orthotopic ovarian tumor xenograft model.