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

项目摘要/摘要 该项目旨在设计一种针对B细胞的有效、特异和临床相关的治疗平台 淋巴瘤，这通常对化疗是无效的。为了实现这一目标，这个项目 开发一种基于多肽的纳米颗粒平台，用于破坏致癌蛋白质-蛋白质相互作用(PPI)和 在不针对其他细胞的情况下，特异性地诱导淋巴瘤B细胞死亡。癌细胞通常上调 支持生存的PPI可以隔离和失活肿瘤抑制蛋白，避免细胞程序性死亡， 这是癌症的特征之一。尽管密集的药理学努力以靶向和干扰 致癌的PPI，只有一种FDA批准的小分子药物可以做到这一点。相比之下，合成肽， 已经成为有希望的颠覆PPI的工具，因为它们更准确地模拟了大型的，阿尔法- 已知的螺旋结合域对许多PPI是至关重要的。然而，取得成功的主要障碍仍然是 将治疗性多肽体内递送到其细胞内靶点，包括：(I)短循环半衰期，(Ii) 非特异性细胞靶向，(Iii)细胞穿透性差，以及(Iv)由于失去α-受体而结合亲和力差 螺旋二级结构。两种分子工程方法，碳氢化合物“装订”的多肽和 尽管如此，多肽-两亲性(PA)纳米颗粒已被用于克服这些障碍的部分 两者都不能同时克服所有这些问题。碳氢化合物结合的多肽是通过添加一种 碳氢化合物在多肽的α-螺旋转角上形成“主链”，从而将其物理地锁定在α-螺旋中 构象和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。同时，PA纳米粒可增强治疗性多肽循环时间、血清稳定性和 细胞摄取，并可通过靶向部分来主动靶向特定类型的细胞。这 该项目寻求同时克服治疗性多肽传递的障碍，通过结合 碳氢化合物固定的多肽和PA纳米颗粒。这项工作旨在通过三种方式做到这一点。第一，合成 并鉴定了一种模仿P53的装订PA(P53-SpA)，旨在重新激活肿瘤抑制蛋白P53 并在弥漫性大B细胞淋巴瘤(DLBCL)中恢复细胞死亡，这是一种大多数临床病例 野生型P53被异常的PPI失活。第二，将重新激活P53的纳米颗粒专门输送到 抗B细胞表面单链可变区抗体的恶性DLBCL细胞 CD19抗原。最后，使用混合PA纳米粒对抗DLBCL的化疗耐药性 靶向p53和bcl2促进生存的协同多肽治疗药物的空间限制传递 PPI。这些目标的成功将创造一种新的有效和专门杀戮的治疗范例 同时避免肿瘤细胞产生化疗耐药性。

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.