Nanoparticle-based target eliminators (NTEs) to guide and monitor protein degradation in hard-to-treat cancers and chemotherapy induced senescence

衰老是由损伤或应激（如化疗）诱导的细胞周期停滞的状态。如果不清除，持续的衰老细胞会诱发慢性局部炎症，从而加剧癌症。目前基于细胞的持续衰老的治疗剂，称为senolytics，受到其细胞毒性的限制，这导致了目前关于通过蛋白质降解的senolysis的建议。所提出的衰老清除策略将特异性促凋亡肽配体缀合到F127多聚多巴胺纳米颗粒（F127-PDA NP）上。通过邻近效应，蛋白质特异性配体将选择性地结合抗凋亡BCL蛋白并使它们接近E3-连接酶（也缀合到NP上），允许前者的泛素化和通过泛素-蛋白酶体途径降解。该项目首先开发了一种用于将BCL蛋白结合肽表面附着到NP上的方案，通过材料表征（例如电子显微镜，质谱）和体外生物学评价（例如共聚焦显微镜，蛋白质印迹）技术进行验证。一旦成功，将修改方案以将E3-连接酶结合肽掺入到NP表面上。两种配体的成功连接将启动体内实验，评估纳米技术在小鼠模型中的安全性和药代动力学特性。所提出的纳米颗粒系统具有模块化能力，如果成功，将具有衰老清除特性。我们设想该系统适用于多种衰老细胞类型，以及这些细胞引起的疾病。

Senescence is a state of cell-cycle arrest induced by damage or stress such as chemotherapeutics. If left uncleared, persistent senescent cells induce chronic local inflammation that exacerbates cancer. Current inhibitor-based therapeutics on persistent senescence, known as senolytics, are restricted by their cytotoxicity, which leads to the present proposal on senolysis via protein degradation. The proposed senolytic strategy conjugates specific proapoptotic peptide ligands onto F127 pluronic-polydopamine nanoparticle (F127-PDA NP). By proximity effect, the protein-specific ligands will selectively bind anti-apoptotic BCL proteins and bring them close to E3-ligase (also conjugated onto the NPs), allowing ubiquitination of the former and degradation via the ubiquitin-proteasome pathway. The projectwill first develop a protocol for surface attachment of BCL protein-binding peptide onto the NP, verified by material characterisation (e.g. electron microscopy, mass spectrometry) and in vitro biological evaluation (e.g. confocal microscopy, western blotting) techniques. Upon success, the protocol will be modified to incorporate E3-ligase-binding peptide onto the NP surface. Successful attachment of both ligands will initiate in vivo experiments that assess the nanotechnology's safety and pharmacokinetic properties in mice models. The proposed nanoparticle system has a modular capability and if successful will possess senolytic properties. We envision that this system applies to multiple senescent cell types, as well as the diseases these cells cause.