Stealth Brusatol and Docetaxel-loaded Nanoparticles for Targeted Prostate Cancer Therapy

摘要 大多数化疗药物在作用机制上依赖于增殖，并对快速 分割细胞。这是一个挑战，因为前列腺癌在临床上生长缓慢。此外，前列腺癌 异质性和目前使用的药物不会杀死所有导致复发和再生的肿瘤细胞群 肿瘤的组织结构。对多西紫杉醇的耐药性是前列腺癌化疗的另一个巨大挑战。 甘露醇是一种细胞内蛋白质合成抑制剂，对核因子红系2具有特异性抑制活性 因子2(NRF2)。因为它抑制蛋白质合成，所以它可以杀死所有的肿瘤细胞，而不考虑异质性。由于其 非选择性作用机制，以及其他对其临床翻译、主动靶向或部位特异性的挑战 向肿瘤输送Brusatol是必不可少的。此外，Brusatol对Nrf2的影响是短暂的。阿司匹林的持续释放 来自给药系统的灯盏花醇可以确保对Nrf2的长期效果，类似于重复剂量。除了它的细胞毒性 除了药效外，鸦胆子醇还可以预防耐药性的发展，并逆转对其他药物的耐药性。 这些方法的创新和优势不胜枚举。纳米颗粒平台是必不可少的：(A)防止或 降低对健康细胞的毒性(由于EPR效应，药物将在肿瘤微环境中释放 通过与PSMA结合来主动靶向)，(B)用于持续药物释放，从而逆转对NRF2的短暂影响，(C) 以增加肿瘤内的药物浓度，从而提高治疗效果。此外，联合疗法还包括 在纳米颗粒平台中的灯盏花醇和多西紫杉醇允许靶向多个途径，从而改善 治疗效果。此外，两种药物的联合使用可通过良好的抗紫杉醇作用预防和/或逆转对多西紫杉醇的耐药性。 已知的已报告机制。这可以解决多西紫杉醇耐药的问题。最后，胡萝卜醇和多西紫杉醇 纳米粒作为在肿瘤微环境中蓄积的结果，可以增强和改善肿瘤的疗效 放射治疗。多西紫杉醇除了具有细胞毒性外，还能显著提高细胞内ROS水平，而灯盏花素则抑制细胞内的ROS 抗氧化反应。这一效应大大增加了肿瘤内的ROS水平。因为放射治疗发挥了它的 通过增加ROS并导致DNA链断裂，纳米颗粒平台有望显著 在肿瘤微环境内加强放射治疗。 我们的假设是，隐形、靶向、灯盏花醇和多西紫杉醇纳米粒的制造将逆转 Brusatol通过持续、连续的纳米粒释放对Nrf2的瞬时影响。纳米粒子联合疗法 将：(1)抑制和/或逆转对多西他赛的耐药性；(2)减少不良反应；(3)提高治疗效果 影响癌细胞的多条增殖途径和部位特异性递送的疗效。要实现 建议的目标，我们有以下目标：(1)隐身的制造、表征和优化，有针对性 灯盏花醇和多西紫杉醇纳米粒和对照。(2)细胞毒性和细胞内化研究，Flow 细胞学分析和其他体外研究将使用荧光染料和载药纳米颗粒进行。(3) 将在小鼠身上进行生物分布、最大耐受量(MTD)和疗效研究。

ABSTRACT Most chemotherapeutic agents are proliferation dependent in their mechanisms of action and are active against rapidly dividing cells. This is a challenge because prostate cancer is clinically slow growing. In addition, prostate cancer is heterogeneous and the drugs currently in use do not kill all populations of tumor cells leading to relapse and regeneration of the tumor. Resistance to docetaxel is another great challenge with chemotherapy of prostate cancer. Brusatol is a protein synthesis inhibitor in cells and it has specific inhibitory activity on nuclear factor erythroid 2-related factor 2 (Nrf2). Because it inhibits protein synthesis, it can kill all tumor cells regardless of heterogeneity. As a result of its non-selective mechanism of action, and other challenges to its clinical translation, the active targeting or site-specific delivery of brusatol to tumors is essential. In addition, the effect of brusatol on Nrf2 is short-lived. The sustained release of brusatol from a delivery system can ensure a prolonged effect on Nrf2 similar to repeated dosing. In addition to its cytotoxic effects, brusatol can also prevent the development of drug resistance and reverse the resistance to other drugs. The innovation and advantages of these approach are numerous. The nanoparticle platform is essential: (a) to prevent or reduce toxicity to healthy cells (the drugs will be released in the tumor microenvironment as a result of the EPR effect and active targeting by binding to PSMA), (b) for sustained drug release and thereby reverse the short-lived effect on Nrf2, (c) to increase drug concentration in the tumor and thereby increase therapeutic efficacy. In addition, combination therapy of brusatol and docetaxel in a nanoparticle platform allows targeting multiple pathways with the resultant improvement in therapeutic efficacy. Furthermore, combination of both drugs can prevent and/or reverse resistance to docetaxel by well- known reported mechanisms. This can solve the problem of docetaxel resistance. Finally, the brusatol- and docetaxel-loaded nanoparticles as a result of accumulation within the tumor microenvironment can augment and improve the efficacy of radiotherapy. Docetaxel, in addition to its cytotoxicity greatly increases the ROS levels while brusatol inhibits the antioxidant response. This effects greatly increase ROS levels specifically within the tumor. Since radiotherapy exerts its effects by increasing ROS and causing DNA strand breaks, the nanoparticle platform holds the promise to significantly augment radiotherapy within the tumor microenvironment. Our hypothesis is that the fabrication of stealth, targeted, brusatol- and docetaxel-loaded nanoparticles will reverse the transient brusatol effect on Nrf2 by sustained, continuous release from nanoparticles. Nanoparticle combination therapy will: (1) suppress and/or reverse chemoresistance to docetaxel (2) reduce adverse effects, and (3) increase therapeutic efficacy as a result of affecting multiple proliferation pathways of cancer cells and site-specific delivery. To achieve the goals of the proposal, we have the following aims: (1) Fabrication, characterization and optimization of stealth, targeted brusatol- and docetaxel-loaded nanoparticles and controls. (2) Cytotoxicity and cellular internalization studies, flow cytometry analyses and other in vitro studies will be carried done using fluorescent dye- and drug-loaded nanoparticles. (3) Biodistribution, maximum tolerable dose (MTD) and efficacy studies will be done in mice.