Targeted Polymer-Adenovirus Hybrids for Ablation of Bladder Cancer Disease

描述（由申请人提供）：拟议的研究描述了基于腺病毒的基因传递载体的发展，用于晚期膀胱癌疾病的靶向消融。膀胱癌是泌尿生殖道第二大常见癌症，2008年有超过68,000例新病例和14,000例死亡。在美国，大多数膀胱癌是移行细胞癌（TCC），尽管鳞状细胞癌（SCC）和腺癌也会发生。浅表病变通过经尿道切除手术切除，但由于残留病变有很高的复发（约80%）和进展（约50%）的风险，患者接受额外的膀胱内治疗。长期随访显示，三分之一最初有浅表病变的患者死于膀胱癌。根治性膀胱切除术是复发性浅表性癌或肌性浸润性膀胱癌的唯一治疗选择。疾病侵入肌肉外壁，通过淋巴系统扩散，形成肝、肺或骨转移。多模式治疗晚期肿瘤的5年生存率仅为20-40%。因此，需要有效的治疗策略，以减少浅表性膀胱癌的复发和进展，并改善晚期患者的治疗效果。使用腺病毒的基因治疗是一种强大的方法，可以传递外源基因，转录毒性蛋白，导致癌细胞消融。虽然这是一种有吸引力的方法，但晚期膀胱癌细胞中柯萨奇-腺病毒受体（CAR）的低表达会导致癌细胞转导不良，而不是正常肝细胞，从而导致全身递送的腺病毒的肝脏毒性。此外，腺病毒的免疫原性也是一个值得关注的问题。开发有效的基因治疗膀胱癌的新途径是必要的。我们提出了一种基于聚合抗体免疫偶联物（PICs）和腺病毒（Ad）的靶向消融膀胱癌细胞的混合系统。新型阳离子聚合物将与抗EGFR抗体结合，以靶向表皮生长因子受体（EGFR），该受体在晚期膀胱癌细胞中过度表达。PICs将与Ad-GFP和Ad-TRAIL病毒络合，所得到的PICs -腺病毒杂种（PAHs）的体外转导效果将在膀胱癌细胞系上进行评估。捕获晚期膀胱癌表型的细胞系将用于拟议的研究。基于adgfp的多环芳烃将用于测定感染性（使用GFP表达）。我们将研究基于adtrail的多环芳烃在表达TRAIL后诱导细胞凋亡的效果，TRAIL已被证明在癌细胞中具有诱导细胞凋亡的选择性。从这些体外实验中选择3种PICs，用于原位膀胱癌动物模型，研究PAH的生物分布和抗肿瘤作用。预计所提出的策略将导致确定安全、有效和靶向消融膀胱癌疾病的新疗法。

DESCRIPTION (provided by applicant): The proposed research describes the development of adenovirus-based gene delivery vectors for the targeted ablation of advanced bladder cancer disease. Bladder cancer is the second most common cancer of the urogenital tract with over 68,000 new cases and 14,000 deaths in 2008. The majority of bladder cancers in the US are transitional cell carcinomas (TCC), although squamous cell carcinomas (SCC) and adenocarcinomas also occur. Superficial lesions are removed surgically by transurethral resection but since residual lesions have a high risk of recurrence (>80%) and progression (~50%), patients receive additional intravesical therapy. Long-term follow up shows that one-third of the patients who initially had superficial lesions die of bladder cancer. Radical cystectomy is the only therapeutic choice for recurrent superficial cancer or muscle invasive bladder cancer. Disease that has invaded beyond the muscle wall, spreads via the lymphatic system forming metastases in liver, lung or bone. Multimodal therapy of advanced tumors results in only 20-40% survival at 5 years. Thus, effective treatment strategies aimed at reducing the recurrence and progression of superficial bladder cancer, as well as improving therapeutic outcome in patients with advanced disease, are needed. Gene therapy using adenoviruses is a powerful approach for delivering exogenous genes that transcribe toxic proteins leading to the ablation of cancer cells. While this is an attractive approach, low expression of the Coxsackie-Adenovirus receptor (CAR) in advanced bladder cancer cells results in poor transduction of cancer cells but not normal hepatocytes, which results in liver toxicity of systemically delivered adenoviruses. In addition, immunogenicity of adenoviruses is a cause for concern. It is necessary to develop novel approaches for efficacious gene therapy of bladder cancer disease. We propose a hybrid system based on polymer-antibody immunoconjugates or PICs, and adenoviruses (Ad) for the targeted ablation of bladder cancer cells. Novel cationic polymers will be conjugated to anti-EGFR antibodies in order to target the Epidermal Growth Factor Receptor (EGFR), which is over-expressed on advanced bladder cancer cells. PICs will be complexed with Ad-GFP and Ad-TRAIL viruses and the in vitro transduction efficacy of the resulting PIC-adenovirus hybrids (PAHs) will be evaluated using bladder cancer cell lines. Cell lines that capture the advanced bladder cancer phenotype will be employed in the proposed studies. AdGFP-based PAHs will be used to determine infectivity (using GFP expression). AdTRAIL-based PAHs will be investigated for their apoptosis-inducing efficacy following the expression of TRAIL, which has been shown to demonstrate selectivity for inducing apoptosis in cancer cells. Three PICs selected from these in vitro experiments will be employed in an orthotopic animal model of bladder cancer to study the biodistribution and anti-tumor efficacy of the PAH. It is anticipated that the proposed strategy will result in the identification of novel therapeutics for the safe, effective, and targeted ablation of bladder cancer disease. PUBLIC HEALTH RELEVANCE: The overall aim of the proposed research is to develop highly effective adenovirus-based gene delivery methods for the ablation of advanced bladder cancer disease. Advanced bladder cancer disease accounts for over 68,000 new cases and 14,000 deaths every year in the United States. We hypothesize that polymer-immunoconjugates (PICs) can be employed in order to selectively target malignant bladder tissue and overcome the limitations associated with currently existing adenoviral cancer gene therapy systems.