Polymeric Nanoparticles for siRNA Delivery to Bone Marrow Endothelium to Disrupt Tumor Cell Adhesion and Bone Metastasis Formation In Vivo

用于将 siRNA 递送至骨髓内皮以破坏体内肿瘤细胞粘附和骨转移形成的聚合物纳米颗粒

• 批准号: 9119490
• 负责人: Michael J Mitchell
• 金额: $ 5.43万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-13 至 2018-08-12
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9119490
• 关键词: Adhesions; Adverse effects; Aftercare; Animal Cancer Model; Binding; Biological Assay; Blocking Antibodies; Blood; Blood Circulation; Bone Marrow; Bone neoplasms; Breast Cancer Cell; CXCR4 gene; Cell Adhesion; Cell Line; Cell membrane; Cells; Cessation of life; Chemotactic Factors; Clinical; Colon; Disease; Distant; Down-Regulation; E-Selectin; Encapsulated; Endothelial Cells; Endothelium; Engineering; Event; Flow Cytometry; Fucosyltransferase; Future; Gene Expression; Gene Silencing; Gene Targeting; Genes; Health; Hepatocyte; Histology; Home environment; Homing; Image; Immune; In Vitro; Invaded; Ligands; Malignant Neoplasms; Malignant neoplasm of prostate; Mentors; Messenger RNA; Metastatic Neoplasm to the Bone; Methods; Modeling; Morbidity - disease rate; Mus; Neoplasm Metastasis; Organ; Patients; Pharmaceutical Preparations; Physiological; Play; Population; Prostate; RNA Interference Therapy; Research; Resistance; Role; Series; Site; Small Interfering RNA; Stem cells; Stromal Cell-Derived Factor 1; Structure; Survival Rate; Technology; Testing; Therapeutic; Training; Tumor Angiogenesis; Work; adhesion receptor; base; bone; career; chemotherapy; dosage; effective therapy; immunogenic; in vivo; in vivo imaging; leukocyte homing; mRNA Expression; migration; monolayer; mouse model; nanoparticle; neoplastic cell; novel; outcome forecast; prostate cancer cell; receptor expression; small molecule; targeted delivery; tumor

 DESCRIPTION (provided by applicant): Metastasis remains responsible for over 90% of cancer-related deaths, and can be described as a series of physical events including tumor cell detachment from the primary site, invasion into the circulation, translocation through the blood to microvessels in distant organs, and transmigration through endothelium to form secondary tumors. One of the most common sites for metastasis is bone, which confers increased morbidity, a 5-year survival rate of ~25%, and median survival of ~40 months. Upon colonization in bone, tumor cells become highly resistant to chemotherapy, and effective treatments remain elusive. Bone marrow endothelial cells (BMECs) constitutively express the adhesion receptor E-selectin (ES) and the chemoattractant stromal cell-derived factor-1 (SDF-1), which bind to ES ligands (ESLs) and CXCR4 on tumor cells, respectively. Such interactions enable the adhesion and homing of tumor cells to BMECs necessary for tumor formation in bone. Down regulation or inhibition of ES and SDF-1 on BMECs provides a potential solution to disrupt bone metastasis formation. However, direct and specific inhibition of constitutive ES and SDF-1 on BMECs by small-molecules has been elusive, and blocking antibodies induce endothelial cell (EC) activation, which can promote further metastasis. Thus, ES and SDF-1 are promising candidates for combination RNA interference (RNAi) therapy, which inhibits traditionally undruggable targets by reducing mRNA expression. The challenge of utilizing siRNA is the need for safe, effective delivery methods, as unmodified siRNA is unstable in the bloodstream, immunogenic, and does not readily cross cell membranes. In the proposed research, we will develop and implement a bone marrow (BM) endothelium-targeted polymeric nanoparticle (NP) siRNA delivery platform to disrupt bone metastasis formation in vivo. Proven endothelium-specific siRNA delivery technology developed by our lab, termed 7C1, will now be functionalized with the targeting moiety Sialyl Lewis-X (SLeX) to enable targeted siRNA delivery and silencing of a target gene in BMECs in vivo, without reducing gene expression in other endothelium (Aim 1). We will conduct a screen to determine the most potent ES and SDF-1 siRNA candidates to encapsulate in targeted 7C1 (t-7C1), verify that t-7C1 can down regulate ES and SDF-1, and determine its efficacy in reducing tumor cell adhesion and transendothelial migration in vitro (Aim II). We will then determine the optimal siRNA dosage to down regulate ES and SDF-1 on BMECs in vivo, test the central hypothesis that down regulation of ES and SDF-1 will disrupt tumor cell adhesion and tumor formation in a mouse model of bone metastasis, and determine potential side effects of our approach on normal stem cell and leukocyte homing to BM (Aim III). The proposed project targets metastasis by disrupting the physical translocation of tumor cells to bone, and presents broadly enabling siRNA delivery technologies to silence multiple genes in BMECs that contribute to a range of diseases.

 描述（由申请人提供）：转移仍然是超过90%的癌症相关死亡的原因，并且可以被描述为一系列物理事件，包括肿瘤细胞从原发部位脱离、侵入循环、通过血液易位到远端器官中的微血管以及通过内皮细胞迁移形成继发性肿瘤。骨转移是最常见的转移部位之一，其导致发病率增加，5年生存率约为25%，中位生存期约为40个月。在骨中定植后，肿瘤细胞变得对化疗具有高度抗性，并且有效的治疗仍然难以捉摸。骨髓内皮细胞（BMEC）组成型表达粘附受体E-选择素（ES）和趋化基质细胞衍生因子-1（SDF-1），它们分别与肿瘤细胞上的ES配体（ESL）和CXCR 4结合。这种相互作用使得肿瘤细胞能够粘附和归巢到骨中肿瘤形成所必需的BMEC。ES和SDF-1对BMEC的下调或抑制提供了破坏骨转移形成的潜在解决方案。然而，通过小分子直接和特异性地抑制BMEC上的组成型ES和SDF-1一直是难以捉摸的，并且阻断抗体诱导内皮细胞（EC）活化，这可以促进进一步的转移。因此，ES和SDF-1是组合RNA干扰（RNAi）疗法的有希望的候选者，其通过降低mRNA表达来抑制传统上不可用药的靶标。利用siRNA的挑战是需要安全、有效的递送方法，因为未修饰的siRNA在血流中不稳定，具有免疫原性，并且不容易穿过细胞膜。在拟议的研究中，我们将开发和实施骨髓（BM）内皮靶向聚合物纳米颗粒（NP）siRNA递送平台，以破坏体内骨转移形成。我们实验室开发的血管内皮特异性siRNA递送技术，称为7 C1，现在将用靶向部分Sialyl Lewis-X（SLeX）功能化，以实现靶向siRNA递送和体内BMEC中靶基因的沉默，而不减少其他内皮中的基因表达（Aim 1）。我们将进行筛选，以确定最有效的ES和SDF-1 siRNA候选物包封在靶向7 C1（t-7 C1）中，验证t-7 C1可以下调ES和SDF-1，并确定其在体外减少肿瘤细胞粘附和跨内皮迁移的功效（Aim II）。然后，我们将确定体内下调BMEC上ES和SDF-1的最佳siRNA剂量，测试ES和SDF-1的下调将破坏骨转移小鼠模型中肿瘤细胞粘附和肿瘤形成的中心假设，并确定我们的方法对正常干细胞和白细胞归巢至BM的潜在副作用（Aim III）。拟议的项目通过破坏肿瘤细胞向骨的物理易位来靶向转移，并提出了广泛的siRNA递送技术，以沉默BMEC中导致一系列疾病的多个基因。