Preclinical Evaluation of Oncolytic HSV for Anaplastic Glioma Therapy

溶瘤HSV治疗间变性胶质瘤的临床前评价 神经胶质瘤在生物标志物表达（或其缺乏）和它们的生物标志物表达（或其缺乏）方面都是基因型异质的。 支持遗传修饰的单纯疱疹病毒（HSV）载体复制的能力。除了 基因表达谱的异质性（GEP），已经鉴定了神经胶质瘤细胞的亚群， 具有类似于神经干细胞的特性，这些细胞被认为负责 胶质瘤复发和专门维持肿瘤克隆。这种细胞亚群，称为 作为脑肿瘤起始细胞或胶质瘤祖细胞（GPC）， 恶性胶质瘤的放射抗性。这些GPC也可能显示对溶瘤的不同敏感性 通过基因工程单纯疱疹病毒单独或结合辐射。抗肿瘤活性的遗传 工程化HSV载体依赖于宿主肿瘤细胞支持HSV感染的能力， 复制的清楚地了解YI34.5-YI34.5介导的增强肿瘤杀伤的机制， 缺失的HSV和受体靶向的野生型HSV载体对于实现改善的临床功效至关重要。我们 已经表明在AYI 34.5 HSV背景中IL-12的表达导致增强的抗肿瘤作用 这种增强的作用是免疫介导的。问题是，这种好处是否也会 在靶向病毒中，病毒克服PKR反应的能力保持完整或 恢复. 项目3有三个基本目标。目的1将确定每种药物的相对溶瘤潜力， 由项目1和2工程化的新型突变型HSV使用不同的进入机制或克服先天性 主机响应。将比较它们单独或与辐射结合对胶质瘤细胞的抗肿瘤活性 与我们目前的Ayi34.5 HSV载体相同。这些研究将（l）确定哪种改良病毒是最好的 能够感染细胞并克服自然宿主防御，并且，（//）导致病毒的工程化， 联合收割机结合这些最佳特征。目标2将侧重于定义一个 图10示出了胶质瘤祖细胞亚群对单独的溶瘤Ayi34.5HSV和伴随照射的溶瘤Ayi34.5HSV的作用。HSV特异性 将测试靶向CDI 33的药物对GPC的功效，同时保留对正常神经胶质细胞的安全性。GEP 将比较GPC和非GPC肿瘤细胞对HSV的耐受性，以揭示对HSV的耐受性的潜在原因。目标3 将完成对基因工程HSV的临床前测试， 相关性（参见说明）： 恶性神经胶质瘤是一种对放疗和化疗都有抵抗力的脑肿瘤，通常是致命的。我们 寻求溶瘤突变型单纯疱疹病毒安全治疗恶性胶质瘤的最佳应用 而且有效。这些研究将建立最有效的基于HSV的策略，既杀死胶质瘤肿瘤， 构成肿瘤主体的细胞和产生神经胶质瘤肿瘤的恶性神经胶质瘤祖细胞 细胞利用肿瘤上的天然和独特进入分子改善病毒溶瘤活性的策略 细胞和遗传信息的转移有望安全地增强溶瘤作用。 项目/生产现场（如果需要额外空间，请使用项目/生产现场表格页） 项目/业绩

Preclinical Evaluation of Oncolytic HSV for Anaplastic Glioma Therapy Gliomas are genotypically heterogeneous, both in biomarker expression (or lack thereof) and in their ability to support replication of genetically modified herpes simplex virus (HSV) vectors. In addition to heterogeneity in Gene Expression Profiles (GEP), a subpopulation of glioma cells has been identified that has properties resembling those of neural stem cells and these cells are believed to be responsible for glioma recurrence and to exclusively maintain the neoplastic clone. This subpopulation of cells, referred to as Brain Tumor-lnitiating Cells or Glioma Progenitor Cells (GPC), contribute significantly to chemoresistance and radioresistance of malignant gliomas. These GPC may also display differential susceptibility to oncolysis by genetically engineered HSV alone or combined with radiation. Anti-tumor activity of genetically engineered HSV vectors is dependent on the ability of the host tumor cell to support HSV infection and replication. A clear understanding of the mechanisms of enhanced tumor killing mediated by both YI34.5- deleted HSV and receptor-targeted wild-type HSV vectors is critical to achieve improved clinical efficacy. We have already shown that IL-12 expression in a AYI34.5 HSV background results in enhanced anti-tumor activity and this enhanced effect is immune-mediated. The question remains whether this benefit would also be seen with a targeted virus in which the virus' ability to overcome the PKR response remains intact or is restored. Project 3 has three fundamental aims. Aim 1 will ascertain the relative oncolytic potential of each of the novel mutant HSV engineered by Projects 1 and 2 to use different entry mechanisms or to overcome innate host responses. Their antitumor activity on glioma cells, alone or combined with irradiation, will be compared with that of our current Ayi34.5 HSV vectors. These studies will (l) determine which modified viruses are best able to infect cells and overcome natural host defenses, and, (//} lead to the engineering of viruses that combine these optimal features. Aim 2 will focus on defining the comparative susceptibility of a subpopulation of glioma progenitor cells to oncolytic Ayi34.5 HSV alone and with irradiation. HSV specifically targeted to CDI 33 will be tested for efficacy on GPC while retaining safety for normal neuroglial cells. GEP of GPC and non-GPC tumor cells will be compared to reveal potential causes for resistance to HSV. Aim 3 will complete preclinical testing of genetically engineered HSV that incorporate all genetic modifications RELEVANCE (See instructions): Malignant gliomas are radiation- and chemotherapy-resistant brain tumors that are universally fatal. We seek to optimize application of oncolytic mutant Herpes Simplex Viruses to treat malignant gliomas safely and effectively. These studies will establish the most effective HSV-based strategy to kill both glioma tumor cells comprising the bulk of the tumor and malignant glioma progenitor cells that give rise to glioma tumor cells. Strategies for improved virus oncolytic activity that utilize native and unique entry molecules on tumor cells and transfer of genetic information are expected to amplify the oncolytic effect safely. PROJECT/PERFORIVIANCE SITE(S) (if additional space is needed, use Project/Perfomnance Site Fomnat Page) Project/Performance