Oncolytic adenovector-mediated TRAIL gene therapy for cancers

描述(申请人提供)：肿瘤坏死因子相关的凋亡诱导配体(TRAIL)和溶瘤病毒载体最近被广泛研究用于癌症治疗。然而，临床前和临床研究表明，这两种药物的临床应用要么是因为它们的抗癌活性较弱，要么是因为它们可能的全身毒性。因此，最大限度地提高它们的抗癌活性并将其全身毒性降至最低的策略对于这些药物在癌症治疗中的成功至关重要。这项建议的目的是确定表达TRAIL基因的肿瘤特异性复制能力(溶瘤)腺载体治疗癌症的有效性和安全性。有待检验的假设是，将病毒治疗和TRAIL基因治疗整合到单一制剂中将提高其在体内的转导效率和诱导细胞凋亡的能力，并且同时表达来自人端粒酶逆转录酶(HTERT)启动子的TRAIL和E1A基因的溶瘤腺载体将针对癌症同时进行病毒治疗和TRAIL基因治疗，从而摧毁肿瘤组织，但保留正常组织。我们的初步研究表明，将TRAIL基因整合到溶瘤腺载体中可以增强肿瘤细胞中的病毒复制和溶瘤作用，无论是在体外还是体内对TRAIL基因敏感或耐药的癌细胞，在正常的人成纤维细胞中的复制活性和细胞毒作用都是最低的。瘤内注射表达TRAIL的溶瘤腺病毒载体可消除从人非小细胞肺癌细胞系在nu/nu小鼠体内建立的所有皮下移植瘤，导致长期无瘤生存。为了进一步验证这一假设，我们将通过评估e1缺失的载体、溶瘤载体和纤维修饰的溶瘤载体在体外和体内的治疗和副作用，确定将hTERT-TRAIL输送到人和同基因叙利亚仓鼠肿瘤的最佳腺病毒载体系统。我们还将确定腺载体引发的免疫反应是否会对抗肿瘤活性或副作用产生任何影响。最后，我们将确定表达TRAIL的溶瘤载体在免疫抑制和免疫活性动物中建立的人和叙利亚仓鼠同基因转移模型中的抗肿瘤活性。完成拟议的研究将使我们能够确定传递hTERT-TRAIL的最佳方法，并开发治疗转移的策略。这些临床前研究的结果也将为TRAIL疗法和溶瘤病毒疗法的未来整合提供坚实的科学基础，并可能导致新的癌症治疗药物的出现。

DESCRIPTION (provided by applicant): The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and oncolytic virus vectors have recently been investigated extensively for cancer therapy. However, preclinical and clinical studies have revealed that the clinical application of these two agents is hampered either by their weak anticancer activity or by their possible systemic toxicity. Therefore, strategies to maximize their anticancer activity and minimize their systemic toxicity are essential to the success of these agents in the treatment of cancers. The goal of this proposal is to determine the efficacy and safety of a tumor-specific replication-competent (oncolytic) adenovector expressing the TRAIL gene for the treatment of cancer. The hypothesis to be tested is that integration of virotherapy and TRAIL gene therapy into a single agent will enhance its in vivo transduction efficiency and apoptosis-induction capacity and that an oncolytic adenovector expressing both the TRAIL and E1A genes from the human telomerase reverse transcriptase (hTERT) promoter will target both virotherapy and TRAIL gene therapy to cancer, destroying tumor tissue but sparing normal tissue. Our preliminary studies showed that incorporating the TRAIL gene into an oncolytic adenovector enhanced viral replication and oncolysis in cancer cells, whether they were susceptible or resistant to the TRAIL gene, both in vitro and in vivo, with minimal replication activity and cytotoxic effects in normal human fibroblasts. Intralesional administration of the TRAIL-expressing oncolytic adenovector eliminated all subcutaneous xenograft tumors established from a human non-small cell lung cancer cell line in nu/nu mice, resulting in long-term tumor-free survival. To further test the hypothesis, we will determine the optimal adenovector systems for the delivery of hTERT-TRAIL to human and syngeneic Syrian hamster tumors by evaluating the therapeutic and side effects of hTERT-TRAIL delivered by an E1-deleted vector, an oncolytic vector, and a fiber-modified oncolytic vector in vitro and in vivo. We will also determine whether an immune response triggered by an adenovector will have any effect on either antitumor activity or side effects. Finally, we will determine the antitumor activity of the TRAIL-expressing oncolytic vector in both human and Syrian hamster syngeneic metastatic models established in both immunocompromised and immunocompetent animals. Completing the proposed studies will allow us to determine the optimal methods for delivery of hTERT- TRAIL and develop strategies for the treatment of metastasis. The results of these preclinical studies will also provide a solid scientific basis for future integration of TRAIL therapy and oncolytic virotherapy and may lead to new therapeutic agents for cancer therapy.