Targeting Adenovirus Vectors to Ovarian Cancer

描述(由申请人提供)：尽管卵巢癌的管理有了很大的改善，但预计美国每年约有13,900名妇女最终无法通过标准治疗而死亡。腹膜扩散是传播的主要途径，并导致显著的发病率。因此，卵巢癌非常适合应用腺病毒抗癌治疗，因为它们允许将载体局部注射到腹膜腔内，并将播散性病变暴露在局部高浓度的载体下。然而，目前的腺病毒载体的一个主要缺点是它们有效地转导排列在腹膜所有主要器官中的非靶向间皮细胞，而不能有效地转导卵巢癌细胞。这种次优的效率和特异性是因为靶癌细胞通常不表达高水平的主要腺病毒受体，柯萨奇-腺病毒受体(CAR)，而非靶向间皮细胞以CAR依赖的方式有效地转导。我们已经在提高腺病毒载体用于癌症应用的特异性方面取得了重大进展。我们已经创建了两个靶向腺病毒载体，它们同时突变以避免与CAR结合，并通过基因重定向与α-β3/5或α-vbeta6整合素受体结合，这两种受体在卵巢癌中都高度表达。我们的初步数据表明，这些载体将避免CAR介导的基因转移到健康的间皮组织，同时有效地靶向表达αvbeta3/5或αvbeta6整合素受体的肿瘤细胞。我们提出的研究的总体目标是寻找一种靶向的表达肿瘤坏死因子-α的治疗性转基因的先导载体，用于卵巢癌的治疗。这种铅必须在至少两个临床前模型中显示出显著的抗肿瘤活性，并具有可接受的毒性特征，以接近临床应用。我们将首先测试这一假设，即通过使用携带标记基因的载体(特定目标1)来靶向提高基因传递的体外和体内效率和特异性。然后，我们将构建携带肿瘤坏死因子转基因的αvbeta3/5或αvbeta6靶向载体。我们将根据预先定义的标准(特定目标2)，通过确定它们是否表现出适当的抗肿瘤活性和毒性特征来测试这些载体作为临床先导的可行性。

DESCRIPTION (provided by applicant): Despite significant improvements in the management of ovarian cancer, approximately 13,900 women per year in the United States are expected to ultimately fail standard therapies and die. Peritoneal spread is the major route of dissemination and leads to significant morbidity. Therefore, ovarian cancer is well suited for the application of adenoviral anti-cancer treatments because they permit a regional administration of the vector into the peritoneal cavity with exposure of disseminated lesions to a locally high concentration of vector. However, a major disadvantage of current adenovirus vectors is that they efficiently transduce non-target, mesothelial cells that line all the major organs in the peritoneal cavity while inefficiently transducing ovarian cancer cells. This suboptimal efficiency and specificity results because the target cancer cells often do not express high levels of the primary adenovirus receptor, the Coxsackie-Adenovirus Receptor (CAR), while the non-target mesothelial cells are efficiently transduced in a CAR-dependent manner. We have made significant strides in increasing the specificity of adenovirus vectors for cancer applications. We have created two targeted adenovirus vectors that are simultaneously mutated to avoid binding to CAR and genetically redirected for binding to either alphavbeta3/5 or alphavbeta6 integrin receptors, which are both highly expressed in ovarian cancers. Our preliminary data indicates that these vectors will avoid CAR-mediated gene transfer to healthy mesothelial tissue while efficiently targeting tumor cells that express either alphavbeta3/5 or alphavbeta6 integrin receptors. Our overall objective in the proposed studies is to identify a targeted lead vector expressing the therapeutic transgene for tumor necrosis factor-alpha (TNF) for the treatment of ovarian cancer. This lead must demonstrate significant anti-tumor activity with an acceptable toxicity profile in at least 2 preclinical models designed to closely mimic the clinical application. We will first test the hypothesis that the in vitro and in vivo efficiency and specificity of gene delivery are improved through targeting using vectors carrying marker genes (Specific Aim 1). We will then construct alphavbeta3/5 or alphavbeta6 -targeted vectors carrying the transgene for TNF. We will test the feasibility of these vectors as clinical leads by determining whether they display appropriate anti-tumor activities and toxicity profiles according to predefined criteria (Specific Aim 2).