Oncolytic adenovector-mediated TRAIL gene therapy for cancers

描述（申请人提供）：肿瘤坏死因子相关凋亡诱导配体（TRAIL）和溶瘤病毒载体近年来在癌症治疗方面得到了广泛的研究。然而，临床前和临床研究表明，这两种药物的临床应用受到其抗癌活性弱或可能的全身毒性的阻碍。因此，最大化其抗癌活性和最小化其全身毒性的策略对于这些药物在癌症治疗中的成功至关重要。本提案的目的是确定表达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。待验证的假设是，将病毒治疗和TRAIL基因治疗整合为一种药物将提高其体内转导效率和诱导细胞凋亡的能力，同时表达来自人类端粒酶逆转录酶（hTERT）启动子的TRAIL和E1A基因的溶瘤腺载体将同时靶向病毒治疗和TRAIL基因治疗癌症，破坏肿瘤组织，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，无论癌细胞对TRAIL基因易感还是耐药，都能增强癌细胞中的病毒复制和溶瘤作用，而在正常人类成纤维细胞中复制活性和细胞毒性作用最小。在nu/nu小鼠中，病灶内给予表达trail的溶瘤腺载体消除了所有由人非小细胞肺癌细胞系建立的皮下异种移植肿瘤，导致长期无肿瘤生存。为了进一步验证这一假设，我们将通过评估e1缺失载体、溶瘤载体和纤维修饰的溶瘤载体在体外和体内传递hTERT-TRAIL的治疗效果和副作用，确定将hTERT-TRAIL传递给人类和同基因叙利亚仓鼠肿瘤的最佳腺载体系统。我们还将确定由腺载体引发的免疫反应是否对抗肿瘤活性或副作用有任何影响。最后，我们将在免疫功能低下和免疫功能正常的人类和叙利亚仓鼠同基因转移模型中确定表达trail的溶瘤载体的抗肿瘤活性。完成提出的研究将使我们能够确定hTERT- TRAIL的最佳递送方法，并制定治疗转移的策略。这些临床前研究的结果也将为未来TRAIL疗法和溶瘤病毒疗法的整合提供坚实的科学依据，并可能为癌症治疗提供新的治疗药物。

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.