NANO-DELIVERY OF MITOCHONDRIA-SPECIFIC CERAMIDE TO OVERCOME TUMOR DRUG RESISTANCE

描述（由申请方提供）：多药耐药（MDR）的发展是癌症化疗管理失败的主要原因。由于所有抗癌药物最终都是通过触发程序性细胞死亡或细胞凋亡来发挥其作用，因此我们克服MDR的策略集中在多模式方法上：（1）增加全身药物递送功效和（2）降低肿瘤细胞凋亡阈值。初步研究表明，脂质第二信使神经酰胺（CER）与紫杉醇（PTX）沿着共同施用显著增强了野生型和耐药SKOV 3人卵巢腺癌模型中的体外和体内化疗效果。在这些敏感和耐药的肿瘤细胞中，由于CER通过线粒体途径发挥凋亡作用，因此我们假设，开发特异性CER衍生物（mito-CER）将更有效地改善对PTX和其他抗癌药物的促凋亡反应。mito-CER衍生物沿着PTX将在靶向表皮生长因子受体（EGFR）的工程化生物可降解聚合物纳米颗粒制剂中在体外和体内共同施用。该R21申请的具体目的是：（1）合成mito-CER衍生物并配制mito-CER和PTX的EGFR靶向肽修饰的聚（ε-己内酯）（PCL）纳米颗粒制剂。(2)在SKOV 3中使用拉曼光谱成像、细胞杀伤效率和单一和组合PTX/mito-CER的凋亡反应来评价紫杉醇特异性细胞内递送（野生型）和SKOV 3 TR（mdr-1阳性）人卵巢腺癌细胞和（3）使用选择的mito-CER衍生物，评价在雌性nu/nu（无胸腺）小鼠中建立的SKOV 3和SKOV 3 TR肿瘤异种移植模型中的体内抗肿瘤功效和凋亡反应。这项研究的结果对于使用多功能纳米治疗方法治疗难治性肿瘤非常有价值，该方法可以有效地递送药物并克服细胞耐药性。本文提出的多模式纳米载体策略将提供一种克服癌症患者MDR的可转化方法。 公共卫生相关性：对各种化疗药物产生耐药性是癌症治疗的主要挑战之一。目前克服肿瘤耐药性的策略依赖于联合不同类别的抗癌药物和增加给予患者的剂量。由于药物组合和剂量不能无限制地增加而不产生严重的毒性后果，因此迫切需要一种克服肿瘤耐药性的合理策略。由于所有化疗药物最终通过称为“程序性细胞死亡或凋亡”的过程发挥其作用，我们提出通过降低肿瘤细胞中的凋亡阈值来克服耐药性。将合成线粒体特异性神经酰胺衍生物，并与抗癌药物紫杉醇共同给药，用于敏感和耐药的人卵巢癌，以增强治疗效果。使用工程聚合物纳米颗粒，我们将提供这种联合治疗肿瘤块以及细胞内的最大凋亡细胞杀伤效果。

DESCRIPTION (provided by applicant): The development of multidrug resistance (MDR) is a major cause of failure in chemotherapeutic management of cancer. Since all anticancer drugs ultimately exert their effect by triggering programmed cell death or apoptosis, our strategy to overcome MDR is focused on a multi-modal approach to: (1) increase systemic drug delivery efficacy and (2) lower the tumor apoptotic threshold. The preliminary studies show that co-administration of the lipid second messenger, ceramide (CER), along with paclitaxel (PTX) significantly enhanced the chemotherapeutic effect in vitro and in vivo in wild-type and resistant SKOV3 human ovarian adenocarcinoma models. In these sensitive and resistant tumor cells, since CER exerts the apoptotic effect through the mitochondrial pathway, we hypothesize that development of mitochondria-specific CER derivatives (mito-CER) would be even more potent in improving the pro-apoptotic response to PTX and other anticancer drugs. The mito-CER derivatives along with PTX will be co-administered in vitro and in vivo in epidermal growth factor receptor (EGFR)-targeted engineered biodegradable polymeric nanoparticle formulations. The specific aims of this R21 application are to: (1) synthesize mito-CER derivatives and formulate EGFR targeting peptide-modified poly(epsilon-caprolactone) (PCL) nanoparticle formulations of mito-CER and PTX. (2) evaluate mitochondria-specific intracellular delivery using Raman Spectral Imaging, cell-kill efficiency, and apoptotic response of single and combination PTX/mito-CER in SKOV3 (wild-type) and SKOV3TR (mdr-1 positive) human ovarian adenocarcinoma cells and (3) using a select mito-CER derivative, evaluate the in vivo antitumor efficacy and apoptotic response in SKOV3 and SKOV3TR tumor xenograft models established in female nu/nu (athymic) mice. The results of this study would be extremely valuable in the treatment of refractory tumors using a multifunctional nano-therapeutic approach that efficiently delivers the drug and can overcome cellular resistance. The multi-modal nanocarrier strategy proposed here would provide a translatable approach to overcome MDR in cancer patients. PUBLIC HEALTH RELEVANCE: Development of resistance to variety of chemotherapeutic agents is one of the major challenges in cancer therapy. Current strategy to overcome tumor drug resistance relies on combining different classes of anticancer drugs and by increasing the doses administered to patients. Since drug combinations and doses cannot be increases limitlessly without serious toxicity consequences, a rationale strategy to overcome tumor resistance is urgently needed. Since all chemotherapeutic agents ultimately exert their effect through a process called "Programmed Cell Death or Apoptosis", we propose to overcome drug resistance by lowering of the apoptotic threshold in tumor cells. Mitochondria-specific ceramide derivatives will be synthesized and co-administered with anticancer drug, paclitaxel, in sensitive and resistant human ovarian cancer to enhance the therapeutic effect. Using engineered polymeric nanoparticles, we will deliver this combination therapy to tumor mass as well as inside the cells for maximum apoptotic cell-kill effect.