Reprogramming Tumor-Associated Macrophages in PDAC with MicroRNA Nano-Vectors

临床前和临床证据表明肿瘤相关巨噬细胞（TAM） 主要是支持免疫抑制、细胞侵袭、血管生成的 M2 表型， 转移和治疗耐药。 该项目的主要目标是评估双（CD44 和 M2pep）靶向基于透明质酸（HA）的自组装纳米颗粒以影响肿瘤相关 巨噬细胞 (TAM) 从主要的 M2 表型复极化至 M1 表型，以改善治疗效果 在 KrasLSL-G12D/ 、 p53fl/fl 基因工程小鼠 (KPC-GEM) 胰腺导管模型中 腺癌（PDAC）。 在我们的初步研究中，我们已经表明功能化的 HA 块形成了模块化的自 组装纳米平台，用于稳定封装核酸构建体，包括小干扰 核糖核酸。这些靶向 CD44 的核壳纳米粒子已显示出有效的 siRNA 递送和下调 体内抗凋亡基因的调控。西斯莱维奇等人。已表明 M2pep 具有优先权 与其他细胞相比，小鼠 M2 极化 TAM 的结合、快速内化和积累。在 在我们的初步调查中，我们观察到 M2pep 序列与 HA 自结合 组装纳米颗粒显示这些纳米颗粒在体外优先积聚在 M2 中 巨噬细胞。 该项目的具体目标如下： Aim-1研究将侧重于制定和 封装在 HA-PEI/HA-PEG/HA-m2pep 纳米组件中的 miR-125b 双链体的表征。目标2 研究将针对纳米组件的体外评估，以重新极化巨噬细胞和 它们调节促炎细胞因子的能力。 Aim-3 研究将解决抗肿瘤的评估问题 封装在 HA-PEI/HA-PEG/HA- 中的 miR-125b 双链体的治疗反应和转移抑制 在 PDAC 的 KPC-GEM 模型中，m2pep 与吉西他滨加白蛋白结合型紫杉醇组合。 这项研究对于评估巨噬细胞复极化（从主要的 M2 到 M1)作为治疗PDAC的治疗策略并使用基于巨噬细胞靶向HA的 纳米粒子传递 microRNA 以实现复极化。基于HA的创新模块化 纳米平台用途极其广泛，可提供高效的核酸封装、有效负载保护和 体内特异性递送至TAM以实现有效的复极化。

Preclinical and clinical evidence suggests that tumor-associated macrophages (TAMs) are predominantly of the M2 phenotype that supports immuno-suppression, cellular invasion, angiogenesis, metastasis, and therapeutic resistance. The main objective of this project is to evaluate microRNA (miR)-125b delivery in a dual (CD44 and M2pep) targeted hyaluronic acid (HA)-based self-assembling nanoparticles to affect tumor associated macrophage (TAM) repolarization from a predominant M2 to M1 phenotype for improved therapeutic effect in in a KrasLSL-G12D/+, p53fl/fl genetically-engineered mouse (KPC-GEM) model of pancreatic ductal adenocarcinoma (PDAC). In our preliminary studies, we have shown that functionalized HA blocks form a modular self- assembling nano-platform for stable encapsulation of nucleic acid constructs, including small interfering RNA. These CD44-targeted core-shell nanoparticles have shown effective siRNA delivery and down- regulation of anti-apoptotic genes in vivo. Cieslewicz, et al. have shown that M2pep has preferential binding, rapid internalization, and accumulation in murine M2-polarized TAM's compared to other cells. In our preliminary investigation, we have observed that conjugation of M2pep sequence to the HA self- assembling nanoparticles shows preferential accumulation of these nanoparticles in vitro in M2 macrophages. The specific aims of the project are as follows: Aim-1 studies will focus on formulation and characterization of miR-125b duplex encapsulated in HA-PEI/HA-PEG/HA-m2pep nano-assemblies. Aim-2 studies will be directed towards in vitro evaluation of the nano-assemblies to re-polarize macrophages and their capacity to regulate pro-inflammatory cytokines. Aim-3 studies will address evaluation of the anti-tumor therapeutic response and inhibition of metastasis of miR-125b duplex encapsulated in HA-PEI/HA-PEG/HA- m2pep in combination with gemcitabine plus nab-Paclitaxel in a KPC-GEM model of PDAC. This study is highly significant in evaluating macrophage repolarization (from predominant M2 to M1) as a therapeutic strategy for the treatment of PDAC and using macrophage targeted HA-based nanoparticles to deliver microRNA for accomplishing repolarization. The innovative modular HA-based nano-platform is extremely versatile to afford efficient nucleic acid encapsulation, payload protection, and specific delivery to TAM in vivo for efficient repolarization.