Iron oxide nanotheranostics for breast cancer

项目摘要 乳腺癌是美国女性最常见的癌症。 在过去的十年里，只有轻微的改善。化疗是治疗乳腺癌的主要方法 癌症患者沿着手术和/或放射治疗，但受限于肿瘤对治疗的抗性 以及在药物递送中缺乏特异性导致全身毒性。癌症免疫和基因治疗 在克服许多乳腺癌获得的耐药性方面显示出了希望。然而，在这方面， 免疫癌症治疗受到阻碍，因为肿瘤逐渐变得不太容易被免疫识别， 内源性肿瘤特异性T细胞随着时间的推移在肿瘤破坏中变得较不活跃。基因疗法是 由于开发运载工具的挑战，这些运载工具必须同时满足一系列严格的 要求，包括，特别是，无毒性，胶体稳定性，小的流体动力学尺寸，长血清半， 以及克服细胞外和细胞内屏障和选择性地抑制肿瘤的能力。 组织中在这个项目中，我们建议开发一种非病毒的多功能纳米载体，具有成像，双重靶向， 和双重治疗能力，以解决目前乳腺癌治疗的局限性。双重目标是 其被配置为通过使用肿瘤靶向配体将治疗基因特异性递送至乳腺癌细胞 并通过肿瘤特异性启动子（TSP）的选择性仅在乳腺癌细胞中诱导基因表达。通过 在我们的设计中整合脾酪氨酸激酶（SYK）和干扰素γ（IFNγ）基因， 纳米载体将同时抑制肿瘤生长并激活T细胞以根除肿瘤。纳米载体 是制定克服细胞外和细胞内的障碍，并尽量减少潜在的毒性。的 纳米载体的氧化铁核的超顺磁性将允许通过MRI进行治疗监测。我们 有三个具体目标：1）开发一种胶体稳定和生物安全的非病毒纳米载体， 的氧化铁核心和可生物降解的聚合物外壳与质粒DNA复合，并研究其 克服基因转染的细胞内屏障。(2)从乳腺癌细胞中分离TSP并克隆它们 转化到RFP编码质粒中，并评估基因转染效率、双靶向能力和 图10示出了纳米载体在体外乳腺癌细胞中的细胞毒性。(3)利用基因构建治疗性纳米载体 SYK、IFNγ和它们的组合，以替换在目的1和2中开发的纳米载体中的RFP基因，以及 研究它们在异种移植和转基因小鼠体内的治疗功能。如果成功，这 协同策略可以显著改善治疗结果并使有害副作用最小化， 并且可以潜在地推广到开发具有不同靶向配体和特异性的基因载体。 防治各种恶性肿瘤的促进剂。

Project Summary Breast cancer is the most common cancer in women in the U.S. The overall cure rate for breast cancer has shown only slight improvement over the past decade. Chemotherapy is the primary therapy for treating breast cancer patients along with surgery and/or radiation therapy but is limited by tumor resistance to the therapy and the lack of specificity in drug delivery causing systemic toxicity. Both cancer immune and gene therapies have shown promises in circumventing the drug resistance acquired by many breast cancers. However, immune cancer therapy is hampered as tumors gradually become less amenable to immune recognition and endogenous tumor-specific T cells become less active in tumor destruction over time. The gene therapy is hindered by the challenges in developing delivery vehicles that must simultaneously meet a series of stringent requirements, including, in particular, non-toxicity, colloidal stability, small hydrodynamic size, long serum half- life, and an ability to overcome both extracellular and intracellular barriers and to selectively transfect tumor tissues. In this project, we propose to develop a non-viral multifunction nanovector with imaging, dual targeting, and dual therapy capabilities to address the limitations of current breast cancer therapies. The dual targeting is configured to deliver therapeutic genes specifically to breast cancer cells by use of a tumor targeting ligand and to induce gene expression only in breast cancer cells via selectivity of a tumor-specific promoter (TSP). By integrating both spleen tyrosine kinase (SYK) and interferon gamma (IFNγ) genes in our design, the nanovector will simultaneously inhibit tumor growth and activate T cells for tumor eradication. The nanovector is formulated to overcome both extra- and intra-cellular barriers and to minimize potential toxicity. The superparamagnetism of the iron oxide core of the nanovector will allow for treatment monitoring by MRI. We have three specific aims: 1) Develop a colloidally stable and biologically safe non-viral nanovector composed of an iron oxide core and a biodegradable polymer shell to complex with plasmid DNAs and study its ability to overcome intracellular barriers for gene transfection. (2) Isolate TSPs from breast cancer cells and clone them into RFP encoding plasmids, and evaluate gene transfection efficiency, dual-targeting capability and cytotoxicity of the nanovector in breast cancer cells in vitro. (3) Construct therapeutic nanovectors using genes SYK, IFNγ, and their combo to replace the RFP gene in the nanovector developed in Aims 1 and 2 and investigate their therapeutic functions in both xenograft and transgenic mice in vivo. If successful, this synergetic strategy could substantially improve the treatment outcome and minimize deleterious side effects, and can be potentially generalized to develop gene vectors with different targeting ligands and specific promoters for combating various malignancies.