Telomerase Specific Caspase Transfer for Gliomas

端粒酶特异性半胱天冬酶转移用于神经胶质瘤

• 批准号: 6679715
• 负责人: SEIJI KONDO
• 金额: $ 19.41万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6679715
• 关键词: BCL2 gene /protein; apoptosis; athymic mouse; cisplatin; combination cancer therapy; combination chemotherapy; cysteine endopeptidases; enzyme activity; fluorescence microscopy; gamma radiation; gene therapy; genetic promoter element; glioma; green fluorescent proteins; immunocytochemistry; luciferin monooxygenase; neoplasm /cancer chemotherapy; neoplasm /cancer radiation therapy; neoplasm /cancer therapy; nonhuman therapy evaluation; telomerase; temozolomide; transfection /expression vector

DESCRIPTION (provided by applicant): Our efforts to treat malignant gliomas are focused on methods to transfer the caspase genes to tumors. Because the apoptotic pathway may be disrupted in tumors and caspases are the mainstay of apoptosis programs, this approach is one of the most promising strategies for cancer gene therapy. However, if caspases were transduced to normal brain cells, they will undergo apoptosis. To restrict induction of apoptosis to tumor cells, we need to establish a tumor specific expression system of caspases. Telomerase is a particularly attractive target for the tumor-targeting system. It is because a vast majority of malignant gliomas have telomerase activity, while most normal brain cells do not. Activation of telomerase is tightly regulated at the transcriptional level of the telomerase catalytic subunit (hTERT). Therefore, we hypothesize that by using the hTERT promoter-driven vector system, the expression of caspases can be restricted to telomerase-positive malignant gliomas. In preliminary studies, we constructed the caspase-8 (initiator caspase) or rev-caspase-6 (executioner caspase) expression vector with the hTERT promoter (hTERT/caspase-8 or rev-caspase-6) and demonstrated that each construct induced apoptosis in telomerase-positive malignant glioma cells, but not in cultured astrocytes lacking telomerase. Furthermore, the growth of subcutaneous tumors in nude mice was significantly suppressed by the treatment with the hTERT/rev-caspase-6. Additionally, the antitumor effect of hTERT/caspase-8 or rev-caspase-6 was enhanced by the combination with anticancer drug, cisplatin. The goal of this proposal is to investigate whether treatment with the hTERT/caspase-8 or rev-caspase-6 construct is an effective approach for telomerase-positive malignant gliomas using an experimental model of human malignant gliomas. The specific aims are: 1) to select tumor model systems for the in vivo treatment with hTERT/caspase-8 or rev-caspase-6 construct, 2) to investigate the antitumor effect of the hTERT/caspase-8 or rev-caspase-6 construct on intracranial tumors, 3) to investigate their in vitro and in vivo antitumor efficacy combined with conventional therapy (cisplatin, temozolomide, or gamma-irradiation), and 4) to investigate the molecular mechanisms underlying the effect of the hTERT/caspase-8 or rev-caspase-6. A unique focus of this work is the emphasis on the telomerase-specific gene transfer of caspases. We anticipate that the studies described in the current proposal will lead to a novel and promising targeting approach for malignant gliomas expressing telomerase activity.

描述（由申请人提供）：我们治疗恶性神经胶质瘤的努力是 专注于将caspase基因转移到肿瘤的方法。因为 在肿瘤中可能会破坏凋亡途径，胱天蛋白酶是 凋亡计划，这种方法是最有前途的策略之一 癌症基因治疗。但是，如果将胱天蛋白酶转导到正常的大脑 细胞，它们会经历凋亡。限制凋亡诱导肿瘤 细胞，我们需要建立胱天蛋白酶的肿瘤特异性表达系统。 端粒酶是针对肿瘤靶向系统的特别有吸引力的靶标。 这是因为绝大多数恶性神经胶质瘤具有端粒酶活性，所以 虽然大多数正常的脑细胞没有。端粒酶的激活紧密 在端粒酶催化亚基的转录水平上调节 （htert）。因此，我们通过使用HTERT启动子驱动来假设 向量系统，胱天蛋白酶的表达可能仅限于 端粒酶阳性恶性神经胶质瘤。在初步研究中，我们构建了 caspase-8（启动器caspase）或Rev-Caspase-6（executioner caspase） 与HTERT启动子（HTERT/caspase-8或Rev-Caspase-6）的表达载体 并证明每个构建体诱导端粒酶阳性的凋亡 恶性神经胶质瘤细胞，但没有缺乏端粒酶的培养的星形胶质细胞。 此外，裸鼠皮下肿瘤的生长显着 被HTERT/REV-Caspase-6治疗抑制。另外， HTERT/caspase-8或Rev-Caspase-6的抗肿瘤效应增强了 结合抗癌药物，顺铂。该提议的目的是 调查使用HTERT/CASPASE-8或REV-Caspase-6处理 构造是端粒酶阳性恶性神经胶质瘤的有效方法 使用人类恶性神经胶质瘤的实验模型。具体目的是： 1）选择用于使用HTERT/caspase-8的体内处理的肿瘤模型系统 或Rev-Caspase-6构建体，2）研究 HTERT/caspase-8或Rev-Caspase-6颅内肿瘤的构建体，3） 研究他们的体外和体内抗肿瘤功效 常规疗法（顺铂，替莫唑胺或γ-辐照），4） 研究效果的分子机制 HTERT/caspase-8或Rev-Caspase-6。这项工作的独特重点是重点 在caspase的端粒酶特异性基因转移上。我们预计 当前提案中描述的研究将导致新颖而有希望的 表达端粒酶活性的恶性神经胶质瘤的靶向方法。