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的多药耐药（MDR）的发展是癌症治疗的重大挑战。耐多药在临床上表现为多种因素的结果，包括全身药物递送效率差，停留时间短，肿瘤肿块和细胞内可用性渗透性差，以及导致耐药表型的微环境选择压力。因此，我们克服MDR的创新策略是基于开发组合设计的纳米制剂文库，其中包含封装的小干扰RNA（针对MDR -1和mrp-1外排转运体以及Bcl-2和survivin抗凋亡基因）和细胞毒性治疗剂（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重要的潜力。该项目的具体目标是：(1)合成和表征基于葡聚糖的宏观结构，包括脂肪酸、巯基、聚乙二醇（PEG）和表皮生长因子受体（EGFR）靶向肽，用于在水介质中组合自组装成纳米结构，可以封装siRNA双链、紫杉醇和阿霉素；(2)在野生型（SK0V3） mdr-1阳性（SKOVSTR）人卵巢腺癌和野生型（NIH-H69）和mrp-1阳性（NIH-H69AR）小细胞肺腺癌细胞中，高通量评价siRNA双链和药物的细胞传递和囊泡稳定性、定量和定性基因沉默效果、细胞毒性和凋亡活性；(3)系统给药后，SK0V3TR和NIH-H69AR异种移植肿瘤模型体内肿瘤靶向疗效、驻留、生物分布概况和非室室药代动力学评估的“靶点”选择；(4)进一步细化“命中”，评估体内基因沉默效果、肿瘤抑制和肿瘤转移抵抗异种肿瘤移植模型在单药和联合sIRNA联合治疗后的抑制作用；(5)在耐药肿瘤模型中，通过测量体重、血细胞计数、肝酶和肝组织病理学的变化来确定单一和联合siRNA/药物联合治疗的急性安全性。在美国，难治性卵巢癌和小细胞肺癌的死亡率仍然很高，该建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具有巨大的希望。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。提高给药效率和克服细胞耐药的多模式方法是成功治疗耐多药癌症患者所必需的。在这项研究中，我们将开发一种新型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，从而沉默耐药细胞中的特定基因。和细胞毒药物，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.