Novel Nanopolymers to Inhibit Angiogenesis and Increase the Anti-tumor Immunity

描述(申请人提供)：我们建议通过抑制血管生成和刺激宿主免疫系统的同时，开发用于治疗乳腺癌的新型厌氧结合物。这些纳米生物结合物基于可生物降解和无毒的多聚马来酸纳米平台，该平台具有共价连接的抗转铁蛋白受体(TFR)单抗，可通过肿瘤血管内皮系统传递，反义寡核苷酸(AON)可抑制血管生成，和/或针对乳腺癌抗原HER2/neu的高效免疫刺激抗体-细胞因子融合蛋白。我们推测，当新的纳米生物聚合物单独使用或联合使用时，将能够通过抑制肿瘤血管生成和随后诱导细胞凋亡以及通过激活先天和获得性免疫反应来多管齐下地攻击癌细胞，从而不仅针对HER2/neu而且针对其他肿瘤抗原产生长期的抗肿瘤免疫。此外，由于肿瘤新生血管内皮细胞过度表达TFR介导的细胞转运，肿瘤过度表达的HER2/neu或TFR靶向，以及纳米聚合物表现出的增强的通透性和滞留(EPR)效应，纳米生物结合物将显示出良好的肿瘤靶向性。使用AON抑制血管蛋白层粘连蛋白-411和/或血管内皮生长因子(VEGF)的表达将达到抗血管生成的效果，这是癌细胞产生的关键因子，需要形成支持肿瘤的新血管。此外，为了实现HER2/neu靶向和免疫激活，我们将使用强大的免疫刺激细胞因子白介素2(IL-2)或白介素12(IL-12)，这种细胞因子将通过抗HER2/neu IgG3细胞因子融合蛋白作为纳米聚合物的一部分输送到肿瘤中。我们还将探索将游离抗体-细胞因子融合蛋白与抗血管生成纳米聚合物结合的效果。重要的是，IL-12也是一种抗血管生成的细胞因子，增强了AON的抗血管生成作用。所提出的纳米生物聚合物在结构和作用机制方面代表了新的和独特的分子。就我们所知，拟议的治疗性分子或其他具有类似作用机制的分子既没有被描述，也没有在开发中。本项目的具体目标是：目标1.纳米生物聚合物的合成和体外表征，目标2.纳米生物聚合物的初步药代动力学和毒理学研究，以及目标3.检测纳米生物聚合物抑制肿瘤生长的能力，并探讨其抗肿瘤保护和免疫记忆的机制。建议的纳米生物聚合物代表了新一代癌症治疗的起点，预计将有效地治疗侵袭性乳腺癌，如过度表达HER2/neu的肿瘤。一种新型的基于纳米生物聚合物的针对表达HER2/neu的癌细胞的治疗方法，具有足够的抑制血管生成和协调抗肿瘤免疫反应的能力，应该会在临床上产生重大影响。

DESCRIPTION (provided by applicant): We propose to develop novel anobioconjugates for the treatment of breast cancer by inhibiting angiogenesis and stimulating the host immune system simultaneously. The nanobioconjugates are based on a biodegradable and non-toxic polymalic acid nanoplatform with covalently attached anti-transferrin receptor (TfR) monoclonal antibody for delivery through the endothelial system of the tumor vasculature, antisense oligonucleotides (AON) to inhibit angiogenesis, and/or potent immunostimulatory antibody-cytokine fusion proteins specific for the breast cancer antigen HER2/neu. We hypothesize that the new nanobiopolymers when used alone or in combination would be capable of a multi-pronged attack against cancer cells by inhibiting tumor angiogenesis with the subsequent induction of apoptosis and by activating innate and adaptive immune responses resulting in long-term anti-tumor immunity not only against HER2/neu but also against other tumor antigens. In addition, the nanobioconjugates would exhibit superior tumor targeting as a consequence of the combination of transcytosis mediated by TfR overexpressed on the endothelial cells of the tumor neovasculature, targeting of HER2/neu or TfR overexpressed by the tumor, and the enhanced permeability and retention (EPR) effect exhibited by nanopolymers. The anti-angiogenic effect would be achieved using AON to inhibit the expression of vascular protein laminin-411 and/or vascular endothelial growth factor (VEGF), critical factors produced by the cancer cells needed to develop new vasculature that supports the tumor. In addition, to achieve HER2/neu targeting and immunoactivation we will use the potent immunostimulatory cytokines interleukin-2 (IL-2) or interleukin-12 (IL-12) that would be delivered into the tumor by an anti-HER2/neu IgG3-cytokine fusion protein as part of the nanobiopolymer. We will also explore the effect of combining free antibody-cytokine fusion proteins with the anti-angiogenic nanopolymer. Importantly, IL-12 is also an anti-angiogenic cytokine increasing the anti-angiogenic effect of AON. The proposed nanobiopolymers represent novel and unique molecules in terms of structure and mechanisms of action. To the best of our knowledge, neither the proposed therapeutic nor other molecules with similar mechanisms of action have either been described or are under development. The specific aims of this project are: Aim 1. Synthesis and in vitro characterization of nanobiopolymers, Aim 2. Initial pharmacokinetic and toxicological studies of the nanobiopolymers, and Aim 3. Examine the ability of nanobiopolymers to inhibit tumor growth and investigate the mechanism responsible for anti-tumor protection and immunological memory. The proposed nanobiopolymers represent the starting point for a new generation of cancer therapeutics and are expected to be effective against aggressive breast cancer tumors such as those overexpressing HER2/neu. A novel nanobiopolymer-based therapy against HER2/neu expressing cancer cells with sufficient capacity to inhibit angiogenesis and orchestrate an anti-tumor immune response should make a significant clinical impact.