Engineering Biomaterials to Modulate the Bone Marrow Microenvironment in Multiple Myeloma

项目摘要 多发性骨髓瘤（MM）约占所有恶性血液病的23%，占癌症相关死亡的2.1% 2022年在美国。尽管做出了巨大努力来开发有效的治疗方法，但MM在很大程度上仍然存在。 几乎所有的患者都对目前的治疗产生了抗药性。因此，临床上迫切需要 创新和改进的MM疗法。已经证明骨髓内皮细胞是至关重要的 MM细胞归巢、进展、存活和耐药性。具体地说，亲环素A和E-选择素， 归巢因子和粘附受体分别由骨髓内皮细胞表达， MM存活率。因此，抑制亲环素A和E-选择素提供了一种潜在的治疗策略，以消除 MM传播和耐药性。然而，直接和特异性抑制亲环素A和E-选择素， 小分子一直难以捉摸。因此，亲环素A和E-选择素是组合的有希望的候选者 RNA干扰（RNAi）疗法，通过直接降低其活性来抑制传统上不可治疗的靶点。 信使RNA（mRNA）表达。利用小干扰RNA（siRNA）的挑战是需要 安全有效的递送方法，因为siRNA在血流中降解， 膜。在我的博士前研究期间，我设计了一个聚合物-脂质混合生物材料库， 与聚乙二醇（PEG）-脂质缀合物和SiRNA组合，组装成纳米颗粒（NP） 通过微流体混合。通过高通量体内筛选，我确定了一个NP制剂， 在体内骨髓内皮细胞中的沉默。该制剂用于包封亲环素A siRNA， 并显示出体内MM进展的抑制，并使MM细胞对蛋白酶体抑制剂硼替佐米敏感， 在F99阶段，我将通过将我们的NP设计与现有的治疗方法相结合来改进NP设计。 在NP表面上的骨髓内皮靶向配体，以增强其对骨髓的特异性 内皮，最大限度地减少脱靶效应。我将用我们的靶向NP共包封亲环素A和E- 选择素siRNA序列，并通过粘附和跨内皮迁移评估其体外抑制作用 测定，以确定MM细胞的侵袭能力。此外，我将测试我们的共同交付siRNA纳米技术， 通过在经验证的MM小鼠异种移植模型中进行的存活研究，并量化其单独或联合 与硼替佐米结合。这项技术有望提供一个广泛的支持平台， 其他骨髓癌在K 00阶段，我将确定一个著名的癌症生物学实验室， 利用高维单细胞研究骨髓免疫微环境中的细胞间相互作用 方法和组织工程模型，旨在确定驱动癌症进展的机制 和耐药性。这个项目的完成将成功地准备我推出一个NIH资助的研究 该实验室专注于靶向肿瘤微环境的药物递送作为癌症治疗的手段。

PROJECT SUMMARY Multiple myeloma (MM) accounts for ~23% of all hematologic malignancies with a 2.1% of cancer-related deaths in the United States in 2022. Despite tremendous efforts to develop effective therapies, MM remains largely incurable, and virtually all patients develop resistance to current therapies. Thus, there is an urgent clinical need for innovative and improved MM therapeutics. It has been demonstrated that bone marrow endothelium is critical to MM cell homing, progression, survival, and drug resistance. Specifically, cyclophilin A and E-selectin, a homing factor and adhesion receptor, respectively, expressed by bone marrow endothelial cells, are critical to MM survival. Thus, inhibition of cyclophilin A and E-selectin provides a potential therapeutic strategy to abolish MM dissemination and resistance. However, direct- and specific-inhibition of cyclophilin A and E-selectin by small molecules has been elusive. Thus, cyclophilin A and E-selectin are promising candidates for combination RNA interference (RNAi) therapy, which inhibits traditionally undruggable targets by directly reducing their messenger RNA (mRNA) expression. The challenge of utilizing small-interfering RNA (siRNA) is the need for safe and effective delivery methods, as siRNA degrades in the bloodstream and does not readily cross membranes. During my predoctoral studies, I have engineered a library of polymer-lipid hybrid biomaterials, that in combination with polyethylene glycol (PEG)-lipid conjugates and siRNA, assembled into nanoparticles (NPs) via microfluidic mixing. Through high-throughput in vivo screening, I identified a NP formulation with potent gene silencing in bone marrow endothelial cells in vivo. This formulation was used to encapsulate cyclophilin A siRNA, and showed inhibition of MM progression in vivo, and sensitized MM cells to the proteasome inhibitor bortezomib, a current therapeutic modality to treat MM. During the F99 phase, I will improve our NP design by incorporating bone marrow endothelial-targeting ligands on the NP’s surface to enhance their specificity to bone marrow endothelium, minimizing off-target effects. I will use our targeted NP to co-encapsulate cyclophilin A and E- selectin siRNA sequences, and evaluate their inhibition in vitro through adhesion and transendothelial migration assays, to determine the invasive abilities of MM cells. Further, I will test our co-delivery siRNA nanotechnology through a survival study in a validated mouse xenograft model of MM and quantify its effects either alone or in combination with bortezomib. This technology is expected to provide with a broadly enabling platform to target other bone marrow-homing cancers. For the K00 phase, I will identify a renowned cancer biology laboratory to study cell-cell interactions in the bone marrow immune microenvironment utilizing high-dimensional single-cell approaches and tissue-engineered models, with the aim to determine mechanisms that drive cancer progression and drug resistance. Completion of this project will successfully prepare me to launch an NIH-funded research laboratory that focuses on drug delivery targeting the tumor microenvironment as means of cancer therapy.