Heat Activated Gene Therapy Using Radiomimetic CdtB

使用拟放射 CdtB 的热激活基因治疗

• 批准号: 6954118
• 负责人: Michael Jude Borrelli
• 金额: $ 24.81万
• 依托单位: UNIV OF ARKANSAS FOR MED SCIS
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-22 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6954118
• 关键词: Adenoviridae; antimetabolites; bacterial toxins; biological signal transduction; biotechnology; blood chemistry; brain neoplasms; cell death; cytotoxicity; gene delivery system; gene expression; gene therapy; genetic transcription; heat shock proteins; heat stimulus; laboratory rabbit; magnetic resonance imaging; neoplasm /cancer thermotherapy; nonhuman therapy evaluation; pancreas neoplasms; polymerase chain reaction; radiation; transfection /expression vector

DESCRIPTION (provided by applicant): The central hypothesis is that effective cancer gene therapy can be achieved using a highly toxic transgene that is expressed controllably from a heat-inducible promoter. To test this, cytolethal distending toxin B (CdtB), the cytotoxic component of a tripartite bacterial proteotoxin, was placed into an adenovirus vector under control of a modified human HSP70B heat shock promoter that is extremely silent until heal shocked at 41.0 degrees C or higher. Aim 1 is to optimize using this heat-activatable CdtB gene therapy to establish local tumor control in a rabbit VX2 brain tumor model and to protract animal survival. Aim two is to deliver the adenovirus vectors with tissue permeabilizing agents that increase the interstitial space to promote vector diffusion throughout solid tumors to ascertain if this increases treatment efficacy. It is postulated that using the permeabilizers will increase the fraction of tumor cells that get infected to express CdtB to control tumors more efficiently and permit larger tumors to be treated successfully. Aim three is to explicate the mechanisms of CdtB bystander killing. Treatment efficacy is dependent upon bystander killing of cells adjacent to those infected with and expressing the CdtB transgene. Although CdtB bystander killing has been observed in vitro and in vivo, little is known about it. Experiments will determine if bystander killing is mediated by a freely diffusible extracellular signal or if cell-cell contact and gap junction communication are requisite. Assays will also establish if the bystander cells die by apoptosis or other death mechanisms and will identify the signals that initiate bystander killing. Some tumors, e.g., glioblastoma multiforme, pancreatic tumors, etc. are more refractory to conventional radiotherapy, and chemotherapy, making local tumor control difficult to achieve. Additionally, many tumors recur locally with high frequency and surgery is often impossible and/or radiotherapy options are limited because surrounding normal tissues have accrued their tolerance radiation dose. Consequently, complementary therapies that can improve local control for primary and recurrent cancers are needed. The proposed study will test the potential of heat-activated CdtB gene therapy to help satisfy this need.

描述（由申请人提供）：中心假设是，可以使用高毒性的转基因来实现有效的癌症基因疗法，该转基因可从热诱导启动子中控制。 为了测试这一点，将三分之一细菌蛋白毒素的细胞毒素B（CDTB）（CDTB）（CDTB）置于控制的腺病毒载体中，该腺病毒载体控制在修改后的人类HSP70B热激启动子的控制下，该促进剂非常静音，直到在41.0摄氏度或更高的head haspe haspe hoppe 。 目的1是使用这种可热活动的CDTB基因疗法优化，以在兔VX2脑肿瘤模型中建立局部肿瘤控制并延长动物的生存。 目标二是将腺病毒载体带有组织通透性剂，从而增加间质空间，以促进整个实体瘤的载体扩散，以确定这是否增加了治疗效果。 据推测，使用透化器会增加感染以表达CDTB以更有效地控制肿瘤的肿瘤细胞的比例，并允许成功治疗较大的肿瘤。 目的三是解释CDTB旁观者杀戮的机制。 治疗功效取决于旁观者杀死与感染和表达CDTB转基因的细胞相邻的细胞。 尽管在体外和体内已经观察到CDTB旁观者杀戮，但对此知之甚少。 实验将确定旁观者杀戮是否是由可自由扩散的细胞外信号介导的，还是细胞 - 细胞的接触和间隙连接通信是必需的。 测定还将确定旁观者细胞是否死于凋亡或其他死亡机制，并将确定引发旁观者杀戮的信号。 某些肿瘤，例如多形胶质母细胞瘤，胰腺肿瘤等对常规放疗和化学疗法更难治性，使得难以实现局部肿瘤的控制。 此外，许多以高频和手术的局部重复出现的肿瘤通常是不可能的，并且/或放射疗法的选择受到限制，因为周围的正常组织已应计耐受性辐射剂量。 因此，需要改善对原发性和复发癌的局部控制的互补疗法。 拟议的研究将测试热激活CDTB基因疗法的潜力，以帮助满足这一需求。