Gutless Adenovirus Mediated Targeted Therapeutics for Glioma

无肠腺病毒介导的胶质瘤靶向治疗

• 批准号: 7331147
• 负责人: Marianela Candolfi
• 金额: $ 4.96万
• 依托单位: CEDARS-SINAI MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7331147
• 关键词: Acute; Adenovirus Vector; Adenoviruses; Adult; Adverse effects; Affect; Affinity; Binding; Biopsy; Brain Neoplasms; Cell Death; Cell Line; Cells; Chimeric Proteins; Clinical; Clinical Trials; Cloning; Complementary DNA; Data; Disease; Dose; Doxycycline; Exotoxins; Figs - dietary; Glioma; Half-Life; Human; Immune; Immune response; Immunity; In Situ; Interleukin-13; Interleukin-4; Lead; Left; Life; Life Expectancy; Longevity; Macroglobulins; Mediating; Monitor; Mus; Mutate; Normal Cell; Nude Mice; Patients; Physiological; Protein Binding Domain; Protein Biosynthesis; Protein Overexpression; Pseudomonas; Regulation; Rodent; Safety; Specificity; System; Targeted Toxins; Testing; Tetracycline Control; Therapeutic; Toxic effect; Toxin; Toxin Conjugates; Transgenes; Treatment Efficacy; Viral Vector; Week; Withdrawal; Xenograft procedure; brain tissue; cancer therapy; cytotoxic; cytotoxicity; gene therapy; improved; in vivo; interleukin-13 receptor; killings; mutant; neoplastic cell; novel; promoter; receptor; research study; therapeutic target; therapeutic transgene; transgene expression; tumor; vector

DESCRIPTION (provided by applicant): Gliobastoma is the most devastating brain tumor in adults and none of the conventional anticancer therapies has been successful in significantly prolonging the lifespan of the patients. More than 80% of gliomas in situ express high amounts of a mutated IL-13 receptor (IL13a2R), different from the one expressed in normal cells. A chimeric toxin consisting of IL-13 fused to a mutated Pseudomonas exotoxin, (PE) has been shown to kill IL-13a2R expressing cells. PE lacks its endogenous protein binding domain, which allows it to bind to the ubiquitous expressed ct2-macroglobulin receptor, but retains its ability to inhibit protein synthesis, which leads to cell death. Thus, its fusion to IL-13 retargets the cytotoxic molecule to IL13a2R-expressing glioma cells. Mutants of IL-13, such as IL13.E13K (mulL-13), have shown negligible binding to normal cells and higher affinity to the glioma-specific IL13a2R when compared to IL-13. However, the systemic treatment with the chimeric toxin requires high concentrations that can induce adverse side effects while the intratumoral treatment requires repeated administration due to the short half life of the toxin. In spite of these limitations this approach is currently considered one of the most exciting novel treatments for this devastating disease, and has provided very encouraging results in early clinical trials performed at various clinical centers. We hypothesize that intratumoral administration of a high-capacity adenoviral vector (HC- Ad) expressing the chimeric protein mulL-13 fused to PE, to human glioma bearing nude mice, will lead to effective intratumoral concentration of the chimeric toxin, killing human glioma cells but preserving normal brain tissue. HC-Ad vectors have the advantage of high cloning capacity and, due to their minimal antigenicity, they elicit stable transgene expression in vivo with low toxicity. To increase the specificity of our approach, we will introduce into the vector the cDNA of mutated IL-4, (mulL4). mulL4 acts as an antagonist, binding to IL13R/IL4R present in normal cells, but it does not interact with IL13a2R expressed on glioma cells, nor does it affect the cytotoxic effects of the chimeric toxin in GBM cells. To further improve the safety of this treatment we incorporated the regulatory TetON system into the vector that allows tight regulation of expression of the therapeutic transgene, by switching it "on" and "off" as and when needed by the addition or withdrawal of doxycycline (DOX). Our previous data provide strong evidence that HC-Ad vectors provide long term, regulated expression of the chimeric toxin even in the presence of systemic anti-adenoviral immunity as present in humans. Thus, we hypothesize that the targeted glioma gene therapy approach proposed will elicit high therapeutic efficacy in the absence of adverse side effects.

描述（由申请人提供）：胶质母细胞瘤是成人中最具破坏性的脑肿瘤，常规抗癌疗法均未成功显著延长患者的寿命。超过80%的胶质瘤原位表达大量突变的IL-13受体（IL 13 a2 R），不同于正常细胞中表达的受体。由融合到突变的假单胞菌外毒素（PE）的IL-13组成的嵌合毒素已显示杀死表达IL-13 a2 R的细胞。PE缺乏其内源性蛋白质结合结构域，这使其能够结合普遍表达的ct 2-巨球蛋白受体，但保留了其抑制蛋白质合成的能力，从而导致细胞死亡。因此，其与IL-13的融合使细胞毒性分子重新靶向表达IL 13 a2 R的神经胶质瘤细胞。IL-13的突变体，如IL13.E13K（穆尔-13），与IL-13相比，已经显示出与正常细胞的可忽略的结合和对神经胶质瘤特异性IL 13 a2 R的更高亲和力。然而，用嵌合毒素的全身治疗需要高浓度，这可能诱导不良副作用，而肿瘤内治疗由于毒素的半衰期短而需要重复施用。尽管存在这些局限性，但这种方法目前被认为是治疗这种毁灭性疾病的最令人兴奋的新疗法之一，并且在各个临床中心进行的早期临床试验中提供了非常令人鼓舞的结果。我们假设向携带人神经胶质瘤的裸鼠瘤内施用表达与PE融合的嵌合蛋白穆尔-13的高容量腺病毒载体（HC-Ad）将导致嵌合毒素的有效瘤内浓度，杀死人神经胶质瘤细胞但保留正常脑组织。HC-Ad载体具有高克隆能力的优点，并且由于其最小的抗原性，它们在体内以低毒性引发稳定的转基因表达。为了增加我们方法的特异性，我们将突变的IL-4（mulL 4）的cDNA引入载体中。mulL 4作为拮抗剂，与正常细胞中存在的IL 13 R/IL 4 R结合，但它不与神经胶质瘤细胞上表达的IL 13 α 2 R相互作用，也不影响嵌合毒素在GBM细胞中的细胞毒性作用。为了进一步提高这种治疗的安全性，我们将调节TetON系统并入载体中，其允许通过在需要时通过添加或撤回多西环素（DOX）来“打开”和“关闭”其来严格调节治疗性转基因的表达。我们先前的数据提供了强有力的证据，即HC-Ad载体提供了嵌合毒素的长期、受调节的表达，即使在存在如人中存在的全身性抗腺病毒免疫的情况下。因此，我们假设，提出的靶向胶质瘤基因治疗方法将在没有不良副作用的情况下引起高疗效。