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

描述（由申请人提供）：我们提出开发新型的通过抑制血管生成和同时刺激宿主免疫系统来治疗乳腺癌的生物缀合物。纳米生物缀合物基于生物可降解且无毒的聚苹果酸纳米平台，其具有共价连接的抗转铁蛋白受体（TfR）单克隆抗体，用于通过肿瘤脉管系统的内皮系统递送，反义寡核苷酸（AON）以抑制血管生成，和/或对乳腺癌抗原HER2/neu特异性的有效免疫刺激性抗体-细胞因子融合蛋白。我们假设，当单独或组合使用时，新的纳米生物聚合物将能够通过抑制肿瘤血管生成并随后诱导细胞凋亡以及通过激活先天性和适应性免疫应答来对癌细胞进行多管齐下的攻击，从而产生不仅针对HER2/neu而且针对其他肿瘤抗原的长期抗肿瘤免疫。此外，纳米生物缀合物将表现出上级肿瘤靶向，这是由肿瘤新血管系统的内皮细胞上过表达的TfR介导的转胞吞作用、由肿瘤过表达的HER2/neu或TfR的靶向以及纳米聚合物表现出的增强的渗透性和保留（EPR）效应的组合的结果。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）的表达将实现抗血管生成作用，所述血管蛋白层粘连蛋白-411和/或血管内皮生长因子（VEGF）是由癌细胞产生的支持肿瘤的新血管系统所需的关键因子。此外，为了实现HER2/neu靶向和免疫活化，我们将使用有效的免疫刺激细胞因子白细胞介素-2（IL-2）或白细胞介素-12（IL-12），其将通过抗HER2/neu IgG 3-细胞因子融合蛋白作为纳米生物聚合物的一部分递送到肿瘤中。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相结合的效果。重要的是，IL-12也是增加AON的抗血管生成作用的抗血管生成细胞因子。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颖和独特的分子。据我们所知，所提出的治疗或具有类似作用机制的其他分子均未被描述或正在开发中。该项目的具体目标是：目标1。纳米生物聚合物的合成和体外表征，目的2。纳米生物聚合物的初始药代动力学和毒理学研究，以及目标3。检查纳米生物聚合物抑制肿瘤生长的能力，并研究负责抗肿瘤保护和免疫记忆的机制。提出的纳米生物聚合物代表了新一代癌症治疗的起点，预计将有效对抗侵袭性乳腺癌肿瘤，如过表达HER2/neu的肿瘤。一种针对HER2/neu表达癌细胞的新型纳米生物聚合物疗法，具有足够的抑制血管生成和协调抗肿瘤免疫应答的能力，应该会产生重大的临床影响。

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.