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

描述(由申请人提供)：多药耐药(MDR)的发展是癌症化疗治疗失败的主要原因。由于所有抗癌药物最终都通过触发细胞程序性死亡或凋亡来发挥作用，我们克服MDR的策略集中在多模式方法上：(1)提高全身给药效率和(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)联合应用可显著提高SKOV3人卵巢癌野生型和耐药模型的体内外化疗效果。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效应，我们假设开发线粒体特异性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衍生物和PTX将在体外和体内以表皮生长因子受体(EGFR)为靶向的工程化可生物降解聚合物纳米颗粒配方共同给药。本R21应用的具体目的是：(1)合成MITO-CER衍生物，并制备EGFR靶向多肽修饰的聚己内酯(PCL)MITO-CER和PTX纳米制剂。(2)利用拉曼光谱成像技术，评价PTX/MITO-CER单独及联合应用对人卵巢癌细胞SKOV3(野生型)和SKOV3TR(MDR-1阳性)的细胞内转运、细胞杀伤效率和凋亡反应的影响；(3)使用一种精选的MITO-CER衍生物，评价PTX/MITO-CER对裸鼠SKOV3和SKOV3TR异种移植瘤模型的体内抗肿瘤效果和细胞凋亡反应。这项研究的结果将在使用多功能纳米治疗方法治疗难治性肿瘤方面具有极其重要的价值，这种方法可以有效地传递药物，并可以克服细胞耐药性。这里提出的多模式纳米载体策略将提供一种可翻译的方法来克服癌症患者的多药耐药。 公共卫生相关性：对多种化疗药物产生抗药性是癌症治疗中的主要挑战之一。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，并通过增加给患者的剂量。由于药物组合和剂量不可能在没有严重毒性后果的情况下无限增加，因此迫切需要一种克服肿瘤耐药性的合理策略。由于所有的化疗药物最终都通过一个称为“细胞程序性死亡或凋亡”的过程发挥作用，我们建议通过降低肿瘤细胞的凋亡阈值来克服耐药性。线粒体特异性神经酰胺衍生物将被合成，并与抗癌药物紫杉醇联合应用于敏感和耐药的人卵巢癌，以增强治疗效果。使用经过改造的聚合物纳米颗粒，我们将把这种联合疗法输送到肿瘤肿块以及细胞内，以实现最大限度的凋亡细胞杀伤效果。

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.