Targeted Platinates/siRNA Combination Therapy for Resistant Lung Cancer

描述（由申请人提供）：在美国，2012 年肺癌导致的死亡人数比任何其他类型的癌症都要多，估计 2012 年美国有 226,160 例新病例和 160,770 例死亡。尽管铂类药物在肺癌化疗中发挥了非常重要的作用，但其主要局限性是全身毒性和快速产生耐药性。因此，迫切需要开发替代策略，以有临床意义的方式有效治疗难治性肺癌，且不会产生相关的毒性负担。 RNA干扰疗法是下调铂类耐药相关特定基因的有效方法，因此可以与难治性肺癌患者的细胞毒性化疗协同作用。 R21提案的主要目的是评估使用亲脂性（脂尾）铂酸盐衍生物和小干扰RNA（siRNA）在基于CD44和表皮生长因子受体（EGFR）靶向的生物相容性透明质酸（HA）自组装纳米系统中传递的肺癌联合疗法的治疗潜力。作为初步研究的一部分，我们开发了一系列修饰的 HA 衍生物，使用“点击”化学缀合，允许组合设计的制剂开发方法用于封装疏水性（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结合额外的功能，包括 EGFR 特异性肽，用于肺癌的双重靶向。 该提案的具体目标如下：（1）综合 以及“脂尾”铂酸盐衍生物和封装以及 siRNA 双链体在基于 HA 的自组装纳米系统中的表征，(2) 使用单一（单独的脂尾铂酸盐）和组合（siRNA 铂酸盐治疗敏感 A549 和顺铂耐药 A549DDP 人非小细胞肺癌细胞）评估体外基因沉默和细胞杀伤功效，以及 (3) 建立 A549 和无胸腺 (nu/nu) 小鼠中的 A549DDP 肿瘤异种移植物以及使用基于 HA 的双靶向自组装纳米系统的单一和组合 siRNA/铂酸盐治疗的抗肿瘤功效和安全性的体内评估对于评估使用安全有效的递送系统克服肿瘤耐药性的体内基因沉默策略具有重要意义。在转基因人类肺癌模型中靶向 HA 纳米颗粒。

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.