Targeted Platinates/siRNA Combination Therapy for Resistant Lung Cancer

描述(申请人提供)：肺癌是导致男性和女性死亡的最多的癌症，2012年美国估计有226,160例新病例和160,770例死亡。虽然铂类药物在肺癌的化疗中发挥了非常重要的作用，但它们的主要局限性是全身毒性和快速获得耐药性。因此，迫切需要开发替代策略，以临床上有意义的方式有效地治疗难治性肺癌，而不会产生相关的毒性负担。RNA干扰治疗是下调与铂耐药相关的特定基因的有效方法，因此，在难治性肺癌患者中，RNA干扰治疗可以与细胞毒化疗协同作用。这份R21提案的主要目的是评估利用CD44和表皮生长因子受体(EGFR)靶向的生物相容透明质酸(HA)自组装纳米系统中传递的亲脂(脂尾)铂酸衍生物和小干扰RNA(SiRNA)联合治疗肺癌的可能性。作为初步研究的一部分，我们开发了一系列改进的HA衍生物，使用“点击”化学共轭，允许组合设计的配方开发方法，用于包裹疏水性(例如，脂尾铂酸盐)和亲水性/带电(例如，siRNA)分子。此外，模块化纳米平台允许加入额外的功能，包括EGFR特异性多肽，用于肺癌的双重靶向。该提案的具体目标如下：(1)综合 目的：(1)研究“脂尾”铂酸盐衍生物和包封物及其siRNA双链在透明质酸自组装纳米系统中的作用；(2)评估单一(脂尾铂酸盐单独)和联合(siRNA铂酸盐)对敏感的A549和顺铂耐药的A549DDP人非小细胞肺癌细胞的体外基因沉默和细胞杀伤效率；(3)建立A549和A549DDP裸鼠移植瘤(NU/NU)，并使用双靶向HA自组装纳米系统对单一和联合siRNA/铂酸盐治疗的抗肿瘤效果和安全性进行评估。本研究对利用安全有效的递送系统在体内评价克服肿瘤耐药的基因沉默策略具有重要意义。在成功完成后，R01阶段的未来研究将集中在评估转基因人类肺癌模型中多基因沉默和双靶向HA纳米颗粒的联合治疗。

DESCRIPTION (provided by applicant): Lung cancer accounts for more deaths than any other types of cancer in both men and women, with an estimated 226,160 new cases and 160,770 deaths in 2012, in the United States. Although platinum drugs have played a very important role in the chemotherapy of lung cancer, their major limitations are systemic toxicity and the rapid acquisition of resistance. As such, there is an urgent need to develop alternative strategies to effectively treat refractory lung cancer in a clinically-meaningful way without the associated toxicity burden. RNA interference therapy can be a powerful approach to down-regulate specific genes involved in platinum resistance and, therefore, can work synergistically with cytotoxic chemotherapy in refractory lung cancer patients. The main objective of this R21 proposal is to evaluate the therapeutic potential for combination lung cancer therapy using lipophilic (lipid-tailed) platinate derivatives and small interfering RNAs (siRNAs) delivered in CD44- and epidermal growth factor receptor (EGFR)-targeted biocompatible hyaluronic acid (HA) based self-assembling nano-systems. As part of the preliminary studies, we have developed a series of modified HA derivatives, using "click" chemical conjugation that allow for combinatorial- designed formulation development approach for encapsulation of hydrophobic (e.g., lipid-tailed platinates) and hydrophilic/charged (e.g., siRNA) molecules. Additionally, the modular nano-platform allows for incorporation of additional functionalities, including EGFR specific peptide, for dual targeting in lung cancer. The specific aims of the proposal are as follows: (1) synthesis and characterization of "lipid tailed" platinate derivatives and encapsulation, along with siRNA duplexes, in HA-based self-assembling nano- systems, (2) evaluation of in vitro gene silencing and cell-kill efficacy using single (lipid-tailed platinate alone) and combination (siRNA+platinate therapy in sensitive A549 and cisplatin-resistant A549DDP human non-small cell lung cancer cells, and (3) establish A549 and A549DDP tumor xenografts in athymic (nu/nu) mice and in vivo evaluation of anti-tumor efficacy and safety of single and combination siRNA/platinate therapy using dual targeting HA-based self-assembled nano-systems. This study is highly significant in evaluating gene silencing strategy in vivo for overcoming tumor drug resistance using a safe and effective delivery system. Following successful completion, future studies in the R01 phase will focus on evaluation of multiple gene silencing and combination therapy delivered with dual targeted HA nanoparticles in a transgenic human lung cancer model.