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药物产生多药耐药(MDR)是癌症治疗中的一个重大挑战。临床上多药耐药是由多种因素引起的，包括全身给药效率低、滞留时间短、肿瘤组织渗透性差、细胞内可利用度差，以及导致耐药表型的微环境选择压力。因此，我们克服MDR的创新战略是基于开发组合设计的纳米剂型文库，该文库包含封装的小干扰RNA(针对MDR-1和MRP-1外排转运体以及抗凋亡基因的Bcl2和Survivin)以及细胞毒性治疗药物(紫杉醇和阿霉素)。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巨大的潜力。本项目的具体目标是：(1)合成和表征基于葡聚糖的含有脂肪酸、硫醇基团、聚乙二醇(PEG)和表皮生长因子受体(EGFR)靶向多肽的大结构，用于在水介质中组合自组装成能够包裹siRNA双链、紫杉醇和阿霉素的纳米结构；(2)对野生型(SK0V3)MDR-1阳性(SKOVSTR)人卵巢癌、野生型(NIH-H69)和MRP-1阳性(NIH-H69AR)小细胞肺腺癌细胞高通量评价siRNA双链和药物的细胞递送和囊泡稳定性、定量和定性的基因沉默效率、细胞毒性和凋亡活性；(3)选择HITS用于全身给药后对SK0V3TR和NIH-H69AR肿瘤移植瘤模型的体内靶向效应、滞留、生物分布和非隔室药代动力学的评价；(4)系统地给予单一和联合siRNA/药物共治疗后，进一步完善“HITS”和评估体内基因沉默、肿瘤抑制和抑制转移耐药肿瘤异种移植模型的基因沉默效果；以及(5)通过测量单一和联合siRNA/药物联合治疗耐药肿瘤模型中体重、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。拟议的临床可翻译策略在治疗难治性卵巢癌和小细胞肺癌方面前景广阔，在美国，这两种癌症的死亡率仍然很高。相关性(见说明书)：肿瘤多药耐药(MDR)是临床癌症治疗中的一个严重挑战。为了成功地治疗癌症患者的多药耐药，需要一种提高药物传递效率并克服细胞耐药性的多模式方法。在这项研究中，我们将开发一类新型的生物相容的基于葡聚糖的聚合物纳米组装结构，用于封装和传递能够沉默耐药细胞中特定基因的小干扰RNA。和细胞毒性药物，以获得最大的细胞杀伤力。

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.