COMBINATORIAL-DESIGNED NANO-PLATFORMS TO OVERCOME TUMOR DRUG RESISTANCE

描述（由申请人提供）：对传统和新一代抗癌治疗药物的多药耐药性（MDR）的发展是癌症治疗中的一个重大挑战。MDR在临床上表现为许多因素的结果，包括全身药物递送效率差、停留时间短、肿瘤块中的渗透性差和细胞内可用性差，以及引起耐药表型的微环境选择压力。因此，我们克服MDR的创新策略是基于开发具有包封的小干扰RNA（针对mdr-1和mrp-1外排转运蛋白以及Bcl-2和存活素抗凋亡基因）和细胞毒性治疗剂（紫杉醇和阿霉素）的组合设计的纳米制剂文库。我们的初步研究表明，这种多模式治疗方法在治疗难治性肿瘤方面具有显着的潜力。本项目的具体目标是：（1）合成和表征具有脂肪酸、巯基、聚乙烯基和聚乙烯基的葡聚糖基宏观结构，（乙二醇）（PEG）和表皮生长因子受体（EGFR）靶向肽，用于在水性介质中组合自组装成可包封siRNA双链体、紫杉醇和多柔比星的纳米结构;（2）siRNA双链体和药物的细胞递送和囊泡稳定性的高通量评价，定量和定性的基因沉默功效，野生型（SK 0 V3）mdr-1阳性（SKOVSTR）人卵巢腺癌和野生型（NIH-H69）和mrp-1阳性（3）选择“命中物”，用于在全身施用后在SKOV 3 TR和NIH-H69 AR肿瘤异种移植物模型中体内评价肿瘤靶向功效、驻留、生物分布概况和评价非房室药代动力学;（4）在全身性施用单一和组合sIRNA/药物共治疗后，进一步细化“命中”并评估体内基因沉默功效、肿瘤抑制和转移抗性肿瘤异种移植物模型的抑制;和（5）通过测量在抗性肿瘤模型中使用单一和组合siRNA/药物共同治疗的体重、血细胞计数、肝酶和肝组织病理学的变化来确定急性安全性特征。提出的临床可转化策略在治疗难治性卵巢癌和小细胞肺癌方面具有巨大的前景，这些癌症在美国仍然具有非常高的死亡率。相关性（见说明书）：肿瘤多药耐药（MDR）是临床肿瘤治疗中的一个严重挑战。一个多模式的方法，提高药物输送效率，以及克服细胞耐药性是必要的，以成功地治疗癌症患者的MDR。在这项研究中，我们将开发一类新的生物相容性葡聚糖基聚合物纳米组装结构，用于封装和递送小干扰RNA，可以沉默耐药细胞中的特定基因。和细胞毒性药物以达到最大的细胞杀伤效果。

DESCRIPTION (provided by applicant): Development of multidrug resistance (MDR) to conventional and newer generations of anticancer therapeutics is a significant challenge in cancer therapy. MDR is presented clinically as a consequence of many factors that include poor systemic drug delivery efficiency, short residence time, poor permeability in tumor mass and intracellular availability, as well as microenvironmental selection pressures that give rise to resistant phenotype. As such, our innovative strategy to overcome MDR is based on development of combinatorial designed nano-formulation libraries with encapsulated small interference RNA (against mdr-1 and mrp-1 efflux transporter and Bcl-2 and survivin anti-apoptotic genes) and cytotoxic therapeutic agents (paclitaxel and doxorubicin). Our preliminary studies show that this multimodal therapeutic approach has significant potential in the treatment of refractory tumors. The specific aims of this project are: (1) to synthesize and characterize dextran-based macrostructures with fatty acids, thiol groups, poly(ethylene glycol) (PEG), and epidermal growth factor receptor (EGFR)- targeting peptide for combinatorial self-assembly in aqueous media into nanostructures that can encapsulate siRNA duplexes, paclitaxel, and doxorubicin; (2) high-throughput evaluation of cellular delivery and vesicular stability of siRNA duplexes and drugs, quantitative and qualitative gene silencing efficacy, cytotoxicity and apoptotic activity in wild-type (SK0V3) mdr-1 positive (SKOVSTR) human ovarian adenocarcinoma and wild- type (NIH-H69) and mrp-1 positive (NIH-H69AR) small cell lung adenocarcinoma cells; (3) selection of "hits" for in vivo evaluation of tumor targeting efficacy, residence, biodistribution profiles, and evaluation of non- compartmental pharmacokinetics in SK0V3TR and NIH-H69AR tumor xenograft models after systemic administration; (4) further refinement of "hits" and evaluation of in vivo gene silencing efficacy, tumor suppression, and inhibition of metastasis resistant tumor xenograft models after systemic administration of single and combination sIRNA/drug co-therapy; and (5) determination of acute safety profiles by measuring changes in body weight, blood cell counts, liver enzymes, and liver tissue histopathology with single and combination siRNA/drug co-therapy in resistant tumor models. The proposed clinically-translatable strategy holds tremendous promise in the treatment of refractory ovarian and small cell lung cancers, which continue to have very high mortality rates in the United States. RELEVANCE (See instructions): Tumor multidrug resistance (MDR) is a serious challenge in clinical cancer therapy. A multimodal approach that enhances drug delivery efficiency as well as overcomes cellular resistance is necessary to successfully treat MDR in cancer patients. In this study, we will develop a novel class of biocompatible dextran-based polymeric nano-assembled structures for encapsulation and delivery of small interfering RNA that can silence specific genes in resistant cells. and cytotoxic drugs for maximum cell-kill effect.