Albumin-binding nanocomplexes for delivery of combination siRNA therapeutics to KRAS-driven cholangiocarcinoma

研究总结 被诊断为晚期胆管细胞癌(CCA)的患者总体预后和面貌较差。 治疗选择有限。小干扰RNA(SiRNA)疗法为沉默提供了一种有吸引力的策略 缺乏FDA批准的分子靶向治疗药物的CCA的致癌驱动因素，特别是KRAS，它 在~22%的肝内和~42%的肝外Cca中发生突变。联合siRNA疗法可能是 旨在抢占在靶向治疗过程中经常出现的代偿性抵抗途径。 此外，siRNA可以靶向于肿瘤部位，避免由于分子上的- 在健康器官中的靶向活性，就像许多小分子药物一样。然而，交付方面的挑战 包括核酸酶降解，快速清除，以及缺乏细胞摄取或内体的机制 ESPOVE传统上限制了siRNA的临床应用。我们团队最近开发了一种技术来 用双脂肪酸(siRNA-L2)化学修饰siRNA，与 内源性白蛋白(Alb-NCS)。由于白蛋白通常在血管系统中长时间循环，但 被肿瘤摄取后，我们发现alb-ncs延长了siRNA循环时间，促进了肿瘤的同质性。 穿透，并增加肿瘤选择性的siRNA摄取。这种技术非常适合于纤维瘤，如 CCA，其主动摄取机制对于输送大的生物疗法是必要的。然而， SiRNA-L2的设计还没有与“机载”功能相结合，以摆脱内小体，这 是siRNA活性的关键障碍。在本项目中，我提出了对siRNA-L2alb-NC进行优化和定制 在CCA中实现有效的肿瘤选择性敲除致癌驱动因素的平台。 这里提出的研究将检验这一假设，即白蛋白-NC介导的联合 针对KRAS和互补耐药途径的siRNA将在KRAS- 导致胆管细胞癌。首先，我将对白蛋白-NCS进行化学优化，以实现有效的内体逃逸和 细胞内siRNA传递。第二，我将证明KRAS的基因靶向与合理结合- 参与mTOR信号转导的特定互补基因靶点或参与KRAS的细胞凋亡途径 治疗耐药。然后，我将使用alb-NCS进行临床前治疗研究，以提供基于KRAS的 针对KRAS突变的原位小鼠肝内CCA模型的siRNA组合。因此，这个项目将 通过开发有效的siRNA解决CCA新的靶向治疗方法的迫切需求 针对KRAS驱动疾病的关键基因组合的交付技术。

Research Summary Patients diagnosed with advanced cholangiocarcinoma (CCA) have poor overall outcomes and face limited treatment options. Small interfering RNA (siRNA) therapeutics offer an attractive strategy for silencing oncogenic drivers of CCA that lack FDA-approved molecularly-targeted therapeutics, particularly KRAS, which is mutated in ~22% of intrahepatic and ~42% of extrahepatic CCAs. Combination siRNA therapeutics may be devised to preempt compensatory resistance pathways that frequently arise in the course of targeted therapy. Furthermore, siRNA may be targeted to sites of malignancy, avoiding adverse effects due to molecularly on- target activity in healthy organs, as is seen with many small molecule drugs. However, delivery challenges including nuclease degradation, rapid clearance, and lack of a mechanism for cellular uptake or endosome escape have traditionally limited clinical use of siRNA. Our group has recently developed technology to chemically modify siRNAs with twin fatty acids (siRNA-L2) that form non-covalent nanocomplexes with endogenous albumin (alb-NCs). Since albumin is ordinarily long-circulating in the vasculature but is actively taken up by tumors, we have found that alb-NCs extend siRNA circulation time, promote homogeneous tumor penetration, and increase tumor-selective siRNA uptake. Such a technology is well-suited for fibrotic tumors like CCA, for which an active uptake mechanism is necessary for delivery of large biologic therapeutics. However, the siRNA-L2 design has not yet been integrated with “on-board” functionality to escape from endosomes, which represent a critical barrier to siRNA activity. In this project, I propose to optimize and tailor the siRNA-L2 alb-NC platform to enable efficient tumor-selective knockdown of oncogenic drivers in CCA. The studies proposed here will test the hypothesis that alb-NC-mediated delivery of a combination of siRNAs targeting both KRAS and complementary resistance pathways will provide therapeutic benefit in KRAS- driven cholangiocarcinoma. First, I will chemically optimize alb-NCs for efficient endosomal escape and intracellular siRNA delivery. Second, I will credential gene targeting of KRAS in combination with rationally- selected complementary gene targets involved in mTOR signaling or apoptotic pathways implicated in KRAS treatment resistance. I will then perform pre-clinical therapeutic studies using alb-NCs to deliver KRAS-based siRNA combinations to orthotopic mouse models of KRAS-mutant intrahepatic CCA. This project will thus address a pressing need for new targeted therapeutic approaches in CCA by developing efficacious siRNA delivery technologies to target key gene combinations in KRAS-driven disease.