A Mannose 6-Phosphate Decorated Transformable Nanoplatform for Targeted Uptake in HER2+ Tumors

摘要 人表皮生长因子受体2(HER2)在超过20%的乳腺癌中过表达，并且 胃癌、结直肠癌、卵巢癌和膀胱癌的发病率较低。在HER2+中 肿瘤，HER2大量过度表达和结构性二聚体，导致无情 下游增殖和生存通路的激活与恶性表型。因为 抗HER2单抗HER2、曲妥珠单抗和派妥珠单抗的高表达 作为单一疗法对这些肿瘤是无效的。它们需要与其他药物结合使用 HER2-靶向治疗、化疗或激素治疗。在这里，我们将进行优化和进一步改进 一种新型HER2介导的、基于多肽的无毒可转化纳米制剂已被证明 作为HER2+乳腺癌异种移植模型的单一疗法，具有很高的疗效。这种受体- 介导性可变形纳米疗法是由一种具有独特结构域的多肽组成的，这种多肽允许自身 在水条件下组装形成胶束并在肿瘤部位转化为纳米纤维， 在那里遇到了HER2。由此产生的纳米纤维网络有效地抑制了HER2 二聚化和下游信号导致肿瘤细胞死亡增加和完全缓解 异种移植模型中的HER2+肿瘤。 自从开发组织特异性靶点以来，蛋白质调节一直是药物设计者的目标 对推进和改善病人护理工作至关重要。最近有几种策略 已开发的包括PROTAC、PHOTAC和LYTAC。这些新的化合物类别 使用正常的细胞机械来降解特定的治疗靶蛋白。目前，LYTAC 利用甘露糖6-磷酸(M6P)受体作为胞外内吞作用的载体 溶酶体的蛋白质/受体。这些载体已经被证明足够强大，可以内部化 用甘露糖6-磷酸修饰的大分子，如抗体。 为了补充这一点，我们将修改我们的纳米平台以产生一种新的HER2靶向 可转化肿瘤靶向纳米平台(TCTN)不仅能直接抑制HER2 二聚化和信号转导导致肿瘤细胞死亡，但也可以隔离和降解HER2在 溶酶体。此外，我们还将研究TCTN将紫杉醇输送到肿瘤部位的可能性 实现这一目标，我们将在可变形的纳米平台HER2结合配体甘露糖6- 磷酸盐和紫杉醇。 具体目标： 1)探索TCTN作为靶向药物载体 2)设计、合成和表征6-磷酸甘露糖修饰的TCTN诱导溶酶体 HER2的基础降解和紫杉醇摄取的增加 3)评价紫杉醇及其修饰的M6P的生物分布和疗效。 纳米颗粒

Abstract Human epidermal growth factor receptor 2 (HER2) is overexpressed in over 20% breast cancers, and to a lesser degree in gastric cancers, colorectal cancer, ovarian cancers and bladder cancers. In HER2+ tumors, HER2s are massively overexpressed and constitutively dimerized, leading to unrelenting activation of down-stream proliferation and survival pathways and malignant phenotype. Because of the high expression level of HER2, trastuzumab and pertuzumab, the two anti-HER2 monoclonal antibodies are ineffective as monotherapy against these tumors. They need to be given in combinations with other HER2-targeted therapy, chemotherapy or hormonal therapy. Here we will optimize and further improve a novel HER2-mediated, peptide-based, and non-toxic transformable nano-agent that has been proven to be highly efficacious as a monotherapy against HER2+ breast cancer xenograft models. This receptor- mediated transformable nanotherapy is comprised of a peptide with unique domains that allow self- assembly forming micelles under aqueous conditions and transformation into nanofibrils at the tumor site, where HER2 is encountered. The resulting nanofibrillar network effectively suppresses HER2 dimerization, and downstream signaling leading to increased tumor cell death and complete remission of the HER2+ tumors in xenograft models. Protein modulation has been a goal of drug designers since the development of tissue specific targets and is crucial to the advancement and improvement of patient care. Several strategies have recently been developed including PROTACs, PHOTACs, and LYTACs. These new classes of compounds employ normal cellular machinery to degrade specific therapeutic target proteins. Currently, LYTACs employ mannose 6-phosphate (M6P) receptors to act as carriers for endocytosis of extracellular protein/receptors to the lysosome. These carriers have demonstrated to be powerful enough to internalize macromolecules decorated with mannose 6-phosphate, such as antibodies. For this supplement, we will modify our nanoplatform to generate a novel HER2-targeting transformable cancer targeting nanoplatform (TCTN) that not only can directly suppress HER2 dimerization and signaling leading to tumor cell death, but can also sequester and degrade HER2 in the lysosome. Additionally we will investigate the potential of TCTN to deliver paclitaxel to the tumor site To achieve this, we will incorporate to the transformable nanoplatform HER2 binding ligands, mannose 6- phosphate and paclitaxel. Specific Aims: 1) to explore TCTN as a targeted drug carrier 2) to design, synthesize, and characterize mannose 6-phosphate decorated TCTN to induce lysosomal based degradation of HER2 and increase uptake of paclitaxel 3) to evaluate the biodistribution and therapeutic efficacy of paclitaxel containing and M6P decorated nanoparticles