GENE THERAPY STRATEGIES TO RADIOSENSITIZE HUMAN TUMOR CELLS

使人类肿瘤细胞放射增敏的基因治疗策略

• 批准号: 6990156
• 负责人: RAYMOND E MEYN
• 金额: $ 15.52万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-14 至 2009-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6990156
• 关键词: Adenoviridae; athymic mouse; cell line; gene therapy; human genetic material tag; neoplasm /cancer radiation therapy; neoplasm /cancer transplantation; radiation sensitivity; transfection; transfection /expression vector; vascular endothelium; xenotransplantation

The overall goal of this project is to further develop the strategy of gene therapy combined with radiotherapy for the treatment of human cancers. This project is a direct extension of specific aim 2 of the prior funding period of this project and is based on extensive progress and preliminary data generated during the last 5 years of support. The primary strategies to be developed involve "gene replacement", i.e. wild-type tumor suppressor genes will be transfected into tumor cells deficient in these genes. Certain genes of this type restore apoptosis propensity and/or restore normal cell cycle checkpoint control and would, therefore, be expected to have radiosensitizing abilities. Thus, the gone therapy vectors to be examined in this context will have dual effects in that they will have antitumor activity when used as single agents and, in addition, have radiosensitizing properties. A specific vector has already been generated that will be tested in detail: adenoviral-mediated mda7 (Ad-mda7). Specifically we propose to answer the following questions: 1) Does Ad-mda7 function to preferentially radiosensitize human tumor cells in vitro? The cells will be grown and treated in vitro and clonogenic survival will be the endpoint. 2) Does Ad-mda7 function to radiosensitize tumor microvascular endothelial cells? Here, we propose to test endothelial cells growing in vitro for radiosensitization by mda7 protein. Cells will be grown and treated in vitro and clonogenic survival will be the endpoint. 3) Does Ad-mda7 function to radiosensitize human xenograft tumorsin vivo? The human tumor cell lines shown to be radiosensitized in aim 1 above will be grown as xenograft tumors in nude mice and treated with Ad-mda7 and radiation in vivo. Tumor growth delay will be the endpoint. 4) What is the molecular mechanism by which Ad-mda7 radiosensitizes human tumor cells? Understanding the molecular basis for the radiosensitization imparted by this gene therapy strategy will enable us to design better gene therapy vectors in the future. Thus, under this aim, we propose to examine those specific molecular pathways of apoptosis, signal transduction and DNA repair known to be affected by this vector that may explain radiosensitization. Knowledge gained through this research will hopefully lead to the development of new, more-effective strategies for combining gene therapy and radiotherapy for the treatment of humar cancer.

该项目的总体目标是进一步发展基因治疗联合放射治疗治疗人类癌症的策略。该项目是该项目先前资助期具体目标 2 的直接延伸，以过去 5 年支持期间产生的广泛进展和初步数据为基础。待开发的主要策略涉及“基因替代”，即将野生型抑癌基因转染到缺乏这些基因的肿瘤细胞中。这种类型的某些基因恢复细胞凋亡倾向和/或恢复正常细胞周期检查点控制，因此预计具有放射增敏能力。因此，在本文中要检查的消失的治疗载体将具有双重作用，因为它们在用作单一药剂时将具有抗肿瘤活性，此外还具有放射增敏特性。已经生成了将进行详细测试的特定载体：腺病毒介导的 mda7 (Ad-mda7)。具体来说，我们建议回答以下问题：1）Ad-mda7是否具有在体外优先对人类肿瘤细胞放射增敏的功能？细胞将在体外生长和处理，克隆形成存活将是终点。 2）Ad-mda7是否具有使肿瘤微血管内皮细胞放射增敏的功能？在这里，我们建议测试体外生长的内皮细胞对 mda7 蛋白的放射增敏作用。细胞将在体外生长和处理，克隆形成存活将是终点。 3) Ad-mda7 是否具有体内人异种移植肿瘤放射增敏作用？上述目标 1 中显示出放射敏感性的人类肿瘤细胞系将作为异种移植肿瘤在裸鼠中生长， 用 Ad-mda7 和体内放射治疗。肿瘤生长延迟将是终点。 4）Ad-mda7使人类肿瘤细胞放射增敏的分子机制是什么？了解这种基因治疗策略所赋予的放射增敏作用的分子基础将使我们能够在未来设计出更好的基因治疗载体。因此，在此目标下，我们建议检查已知受该载体影响的细胞凋亡、信号转导和 DNA 修复的特定分子途径，以解释放射增敏作用。通过这项研究获得的知识有望有助于开发出新的、更有效的策略，将基因疗法和放射疗法结合起来治疗人类癌症。