Targeting WASF3 to suppress metastasis

该提案的重点是有效靶向WASF 3稳定性所需的关键蛋白质-蛋白质相互作用 使用钉合肽（SP）作为抑制乳腺癌细胞侵袭和转移的手段作为证据- 并且还可以广泛地应用于依赖于WASF 3进行侵袭和转移的其他癌症。 与那些患有转移性癌症的女性相比，患有转移性癌症的女性的治疗选择有限，寿命较短。 惰性肿瘤目前的理解表明，在远处器官的成功转移定植 这取决于WASF 3基因的表达。在改善治疗选择方面取得进展的一个关键障碍是 转移是缺乏靶向转移过程的常规药物。该项目的目标是 开发创新和优化的靶向策略，以阻断WASF 3功能，从而抑制入侵， 乳腺癌细胞的转移。一种新兴的抑制蛋白质功能的方法是通过靶向蛋白质， 使用钉合肽（SPs），靶点的功能所必需的相互作用。SP含有修饰的氨基 保持稳定的α螺旋构象的酸，其对蛋白水解具有抗性，促进活性细胞 摄取并且不具有免疫原性。WASF 3通常通过以下方式保持在自抑制构象中： 与CYFIP 1和NCKAP 1相互作用，这是WASF调节复合物的重要组成部分 （WRC）。这些蛋白质中的任何一种的敲低导致WASF 3复合物的不稳定和WASF 3复合物的抑制。 侵袭和转移。初步数据显示，针对CYFIP 1-WASF 3和CYFIP-NCKAP 1 使用SP的相互作用导致体外侵袭和体内转移的抑制。这些SP原型 但是已经表明，SP的广泛修饰可以 显著提高其功效。我们的目标包括优化这些SP以增加其溶解度， 使用设计和药物化学方法开发更有效的生物制剂， 确定抑制转移的最有效的衍生物。然后，优化的SP将用于 使用多种转移性乳腺癌的小鼠模型的转移的体内模型，以评估它们的能力 来抑制转移我们还将使用一个斑马鱼模型的内渗，以测试的假设， WASF 3通过其对MMPs和NFkB信号传导的控制，对于侵入血管至关重要。我们有 已经表明，活性肽的微小修饰增加了它们在体外的有效性。这些证据 原理实验表明，SP可以靶向细胞内蛋白质，并可能作为一种有效的 解剖和抑制肿瘤转移策略。这些研究的影响是基于以下知识： WASF 3功能背后的基础生物学允许使用第二代肽技术， 针对WASF 3的高度特异性功能。因此，改进的治疗方法的开发 治疗转移性疾病的方法将对临床治疗产生深远的影响。 乳腺癌（以及潜在的其他癌症）患者的管理。

This proposal focuses on efficiently targeting critical protein-protein interactions required for WASF3 stability using stapled peptides (SPs) as a means of suppressing breast cancer cell invasion and metastasis as a proof- of-principle and may also apply broadly to other cancers that depend on WASF3 for invasion and metastasis. Women with metastatic cancers have limited treatment options and shorter lifespans compared to those with indolent tumors. Current understanding suggests that successful metastatic colonization in distant organs depends on expression of the WASF3 gene. A critical barrier to progress in improving treatment options for metastasis is the lack of conventional drugs that target the metastasis process. The goal of this project is to develop innovative and optimized targeting strategies to block WASF3 function and so inhibit invasion and metastasis in breast cancer cells. An emerging approach to suppress protein function is by targeting protein interactions essential for the function of the target using stapled peptides (SPs). SPs contain modified amino acids that maintain a stable alpha helix conformation that is resistant to proteolysis, promotes active cellular uptake and is not immunogenic. WASF3 is normally held in an autorepressed conformation through interactions with CYFIP1 and NCKAP1, which are essential components of the WASF Regulatory Complex (WRC). Knockdown of any of these proteins leads to destabilization of the WASF3 complex and suppression of invasion and metastasis. Preliminary data shows that targeting the CYFIP1-WASF3 and CYFIP-NCKAP1 interactions using SPs leads to suppression of invasion in vitro and metastasis in vivo. These prototype SPs could be used in preclinical studies but it has been shown that a wide range of modification of SPs can significantly improve their efficacy. Our objectives include optimizing these SPs to increase their solubility, specificity and stability using design and medicinal chemistry approaches to develop more potent biologics and determine the most effective derivatives that suppress metastasis. The optimized SPs will then be used in in vivo models of metastasis using a variety of mouse models of metastatic breast cancer to evaluate their ability to suppress metastasis. We will also use a zebrafish model of intravasation to test the hypothesis that WASF3, through its control of MMPs and NFkB signaling, is vital for invasion into blood vessels. We have already shown that minor modifications of active peptides increase their effectiveness in vitro. These proof-of- principle experiments demonstrate that SPs can target intracellular proteins and may serve as an effective strategy to dissect and inhibit tumor metastasis. The impact of these studies is based on the knowledge of the fundamental biology behind WASF3 function allowing the use of second-generation peptide technology to target the highly specific functions of WASF3. As a result, the development of improved therapeutic approaches for the treatment of the metastatic disease will have profound implications for the clinical management of breast (and potentially other) cancer patients.