Design of Oncolytic Adenovirus Conjugated with Novel Polymer for Cancer Treatment

描述(申请人提供)：该项目的总体目标是构建具有设计的聚合物的智能溶瘤腺病毒(Ad)，该聚合物可系统地用于治疗原发和转移癌症。我们已经证明，这种高效的系统递送克服了与免疫反应、血液循环时间短和肿瘤靶向性差相关的障碍。众所周知，溶瘤的Ad可以选择性地在肿瘤细胞内复制并杀死肿瘤细胞，而不损害正常细胞。随着包括治疗性转化盒在内的溶瘤Ad基因组在癌细胞中复制，治疗性基因的扩增和Ad复制介导的溶瘤作用可以最大限度地发挥其杀瘤作用。C-Met特异性shRNA表达的肿瘤溶解Ad(RDB/shMet)将通过病毒裂解和siRNA介导的长时间沉默c-Met而获得相加的治疗效果。生物可还原聚合物精氨酸半胺双丙烯酰胺己基(ABP)将被聚乙二醇化，并与肿瘤靶向多肽(ABP-PEG-多肽)偶联。RDB/shMet溶瘤广告的表面随后将与ABP-PEG-多肽结合，通过使溶瘤广告逃避免疫细胞和抗体的捕获来改善全身递送。在对ABP-PEG-肽偶联的溶瘤Ad进行物理鉴定后，将评估肿瘤归巢多肽依赖的细胞进入和肿瘤特异性杀伤效果。SMART的疗效和安全性 溶瘤的Ad纳米复合体将在代表临床相关肿瘤模型的原位肿瘤模型中进行评估。将评估对Ad的免疫反应、肝脏毒性、血液清除情况和身体分布情况。由于其复制系统的特点和聚合物的系统性递送，聚合物屏蔽和肿瘤靶向的Ad纳米复合体可能具有协同治疗作用。ABP-PEG-肽偶联的溶瘤Ad可逃避中和抗Ad抗体，减少肝脏蓄积，减少与血液成分的相互作用，从而延长静脉注射后的血液循环时间。此外，EPR介导的被动靶向和肿瘤特异性多肽介导的主动靶向都可以显著提高肿瘤特异性靶向。更重要的是，溶瘤Ad在肿瘤选择性感染后能持续复制和感染邻近肿瘤细胞，最终提高治疗价值。此外，对肿瘤细胞的有限选择性降低了正常细胞的毒性，使治疗成为可能 原发灶和转移灶通过全身递送。

DESCRIPTION (provided by applicant): The overall goal of this project is to construct smart oncolytic adenovirus (Ad) with designed polymer which can be administered systemically to treat primary and metastatic cancer. We have demonstrated that this efficient systemic delivery of Ad overcome the obstacles associated with immune reaction, short blood circulation time and poor tumor targeting of Ad. Oncolytic Ad has been well-known to selectively replicate in and kill tumor cells, while sparing normal cells. As oncolytic Ad genome including therapeutic transgene cassette replicates in cancer cells, the level of cancer- killing effect can be maximized by amplification of therapeutic gene as well as Ad replication-mediated oncolysis. c-Met-specific shRNA-expressing oncolytic Ad (RdB/shMet) will be generated and characterized for additive therapeutic efficacy through viral oncolysis and long lasting siRNA-mediated silencing of c- Met. Bioreducible polymer, arginated cystamine bisacrylamide hexyl (ABP) will be pegylated and conjugated with tumor-targeting peptides (ABP-PEG-Peptide). Surface of RdB/shMet oncolytic Ad will then be conjugated with ABP-PEG-Peptide to improve systemic delivery by enabling oncolytic Ads to evade capture by immune cells and antibodies. After physical characterization of ABP-PEG-Peptide-conjugated oncolytic Ad, tumor- homing peptide-dependent cell entry and tumor-specific killing efficacy will be evaluated. Therapeutic efficacy and safety profile of smart oncolytic Ad nanocomplex will be assessed in orthotopic tumor models which represent a clinically relevant tumor model. Immune response against Ad, liver toxicity, blood clearance profile, and body distribution profile will be assessed. Polymer-shielded and tumor-targeted oncolytic Ad nanocomplex may have a synergistic therapeutic effect due to features of its replicating system of Ad and systemic delivery of polymers. ABP-PEG-Peptide- conjugated oncolytic Ad may evade neutralizing anti-Ad Abs and decreases both liver accumulation and interaction with blood components, which results in extended blood circulation time after intravenous injection. In addition, cancer-specific targeting can be significantly improved by EPR-mediated passive targeting as well as tumor-specific peptide-mediated active targeting. More importantly, oncolytic Ad can keep continuously replicating and infecting neighboring tumor cells after tumor-selective infection, ultimately enhancing therapeutic value. Further, the restricted selectivity to tumor cells reduces toxicity of normal cells, making it possible to treat primary and metastatic lesions via systemic delivery.