A Potent and Specific Approach to Targeting B-Cell Lymphoma: Disrupting Malignant Protein-Protein Interactions Using CD19-Targeted Stapled Peptide Amphiphile Nanoparticles

项目总结/摘要 该项目旨在设计一种有效的，特异性的和临床相关的治疗平台，以靶向B细胞 淋巴瘤，其通常对化学治疗难治。为了实现这一目标，该项目 开发了一种基于肽的纳米颗粒平台，用于破坏致癌蛋白-蛋白相互作用（PPI）， 在淋巴瘤B细胞中特异性诱导细胞死亡，而不靶向其它细胞。癌细胞通常会上调 促存活PPI，以隔离和抑制肿瘤抑制蛋白并逃避程序性细胞死亡， 这是癌症的标志之一尽管密集的药理学努力，以靶向和破坏 对于致癌PPI，只有一种FDA批准的小分子药物可以做到这一点。相反，合成肽， 已经成为破坏PPI的有前途的工具，因为它们更准确地模拟了大的α- 螺旋结合结构域已知对许多PPI至关重要。然而，要成功地实现这一目标， 治疗性肽向其细胞内靶标的体内递送，包括：（i）短循环半衰期，（ii） 非特异性细胞靶向，（iii）差的细胞渗透，和（iv）由于α- 螺旋状二级结构两种分子工程方法，碳氢化合物"钉合"肽和 肽-两亲物（PA）纳米颗粒已被用于克服这些障碍的子集，尽管 两者都不能同时克服。烃钉合肽是通过添加 烃"钉合"穿过肽的α-螺旋转角以将其物理锁定在α-螺旋环中。 通过改变蛋白质的构象，可以更准确地模拟天然蛋白质的结构，并提高与其结合的亲和力。 目标PA纳米颗粒，同时，提高治疗肽循环时间，血清稳定性， 细胞摄取，并且可以用靶向部分官能化以主动靶向特定细胞类型。这 该项目旨在同时克服治疗肽输送的障碍， 烃钉合肽和PA纳米颗粒。这项工作旨在通过三种方式做到这一点。首先， 并表征了设计用于重新激活肿瘤抑制蛋白p53的p53模拟钉合PA（p53-sPA）， 并恢复弥漫性大B细胞淋巴瘤（DLBCL）的细胞死亡，这是一种大多数临床病例都患有的癌症 野生型p53被异常PPI灭活。第二，将p53再活化纳米颗粒特异性地递送至 使用B细胞表面特异性抗体单链可变片段（scFv）的恶性DLBCL细胞 CD19抗原。最后，使用混合PA纳米颗粒对抗DLBCL的化疗耐药性， 在空间上限制靶向p53和BCL 2促存活的协同肽治疗剂的递送 PPI。这些目标的成功将创造一个新的治疗模式， 癌细胞，同时避免化疗耐药性的发展。

PROJECT SUMMARY/ABSTRACT This project seeks to engineer a potent, specific, and clinically relevant treatment platform to target B-cell lymphoma, which is often refractory to chemotherapeutic treatments. To accomplish that goal, this project develops a peptide-based nanoparticle platform for disrupting oncogenic protein-protein interactions (PPIs) and inducing cell death specifically in lymphoma B cells without targeting other cells. Cancer cells often upregulate pro-survival PPIs to sequester and inactivate tumor suppressor proteins and evade programmed cell death, which is one of the hallmarks of cancer. Despite intensive pharmacologic efforts to target and disrupt oncogenic PPIs, only one FDA-approved small-molecule drug exists to do so. Synthetic peptides, in contrast, have emerged as promising tools for disrupting PPIs because they more accurately mimic the large, alpha- helical binding domains known to be crucial for many PPIs. However, major barriers remain to successful in vivo delivery of therapeutic peptides to their intracellular targets, including: (i) short circulation half-lives, (ii) non-specific cellular targeting, (iii) poor cellular penetration, and (iv) poor binding affinity due to loss of alpha- helical secondary structure. Two molecular engineering approaches, hydrocarbon “stapled” peptides and peptide-amphiphile (PA) nanoparticles, have been used to overcome subsets of these obstacles, though neither overcomes them all simultaneously. Hydrocarbon stapled peptides are formed by adding a hydrocarbon “staple” across alpha-helical turns of a peptide to physically lock it in an alpha-helical conformation and more accurately mimic the structure of the native protein and improve binding affinity to its target. PA nanoparticles, meanwhile, enhance therapeutic peptide circulation times, serum stability, and cellular uptake, and can be functionalized with targeting moieties to actively target specific cell types. This project seeks to simultaneously overcome the barriers to therapeutic peptide delivery by combining hydrocarbon stapled peptides and PA nanoparticles. This work aims to do so in three ways. First, synthesize and characterize a p53-mimicking stapled PA (p53-sPA) designed to reactivate tumor suppressor protein p53 and reinstate cell death in diffuse large B cell lymphoma (DLBCL), a cancer in which most clinical cases have wildtype p53 inactivated by aberrant PPIs. Second, deliver p53-reactivating nanoparticles specifically to malignant DLBCL cells using antibody single-chain variable fragments (scFvs) specific for B-cell surface antigen CD19. Lastly, combat chemotherapeutic resistance in DLBCL using mixed PA nanoparticles to spatially constrain the delivery of synergistic peptide therapeutics targeting the p53 and BCL2 pro-survival PPIs. The success of these aims will create a new treatment paradigm for potently and specifically killing cancer cells while avoiding the development of chemotherapeutic resistance.