TARGET SPECIFIC GENE THERAPY OF PROSTATE CANCER

前列腺癌的靶向特异性基因治疗

基本信息

批准号：
2895221
负责人：
Shen Pang
金额：
$ 7.74万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
1995
资助国家：
美国
起止时间：
1995-07-01 至 2001-06-30
项目状态：
已结题

项目摘要

DESCRIPTION: (Applicant's Abstract) Prostate cancer is the leading neoplasm in American men. Two hundred thousand new cases will be diagnosed in 1994 resulting in 38,000 deaths. Thus far, no effective treatment has been developed for patients with advanced, and especially hormone refractory, disease. The development of novel therapeutic strategies is paramount. The use of suicide genes to selectively eradicate tumor cells has shown promise. Driven by tumor tissue-specific promoters, these genes can be transcribed selectively in the neoplastic cells and subsequently cause their destruction. The applicant has characterized a prostate tissue-specific promoter, derived from the 5' flanking sequence of human prostate-specific antigen (PSA) gene. This promoter element has shown strong activity in PSA- producing prostate cancer cells, but not in non-PSA-producing cells. Since the tumor cells from vast majority of patients with advanced prostate disease produce PSA, utilizing this PSA promoter to drive a therapeutic gene exclusively in prostate tissue should alleviate concerns of systemic toxicity while being extremely effective. He has increased the promoter activity four- to five- fold by inserting the cytomegalovirus (CMV) enhancer upstream. Simultaneously, he has analyzed different delivery vectors to maximize gene transfer into prostate tumor cells, and found that the adenoviral vector offers significant advantages due to its high infectivity and gene expression. He will now create an adenoviral construct with a suicide effector gene driven by the CMV-PSA promoter, in the hope that this will selectively eradicate prostate tumor cells. The thymidine kinase gene (TK) has been successfully used to treat several human neoplasms. When a tumor cell transfected with TK is exposed to ganciclovir, DNA replication is disrupted and the cell is eventually destroyed. Unfortunately, prostate cancer cells replicate slowly and may not be susceptible to the actions of a therapeutic gene that requires active cell division. In this case, a suicide gene with direct lytic activity may be better. An example of this is diphtheria toxin A. Hence, the applicant will try both types of agents and assess which is most effective for prostate cancer gene therapy: the TK gene and the DTA gene, alone and in combination with TK. This proposed strategy will be tested in both cell culture and animal models. From in vitro experiments will determine the efficacy and selectivity of the chosen suicide gene. With this basic knowledge, we will then infect tumor- bearing SCID mice with our tissue-specific promoter-driven adenoviral vector to define in vivo selectivity and safety.

描述：（申请人的摘要）前列腺癌是领先的美国男人的肿瘤。二十万新案件将是 1994年诊断出38,000人死亡。到目前为止，没有有效已经针对患有晚期，尤其是的患者开发了治疗激素难治性，疾病。新型治疗的发展策略至关重要。自杀基因的使用选择性根除肿瘤细胞已显示出希望。由肿瘤组织特异性驱动启动子，这些基因可以在肿瘤中有选择地转录细胞并随后造成破坏。申请人表征了前列腺组织特异性启动子，源自人前列腺特异性抗原的5'侧翼序列（PSA）基因。该启动子元素在PSA中表现出很强的活性产生前列腺癌细胞，但不在非PSA产生的细胞中。由于绝大多数患者的肿瘤细胞前列腺疾病产生PSA，利用该PSA启动子驱动A 专门在前列腺组织中的治疗基因应减轻对全身毒性的担忧，同时非常有效。他有通过插入四到五倍的启动子活动巨细胞病毒（CMV）增强子上游。同时，他分析了不同的递送向量以最大化基因转移到前列腺肿瘤细胞中，发现腺病毒矢量由于其高感染力和基因表达。他现在将与 CMV-PSA启动子驱动的自杀效应子基因，希望这将有选择地根除前列腺肿瘤细胞。胸苷激酶基因（TK）已成功用于治疗几个人肿瘤。当用TK转染的肿瘤细胞暴露于 ganciclovir，DNA复制被破坏，细胞最终被被摧毁。不幸的是，前列腺癌细胞复制缓慢，并且可能不容易受到需要的治疗基因的作用主动细胞分裂。在这种情况下，具有直接裂解的自杀基因活动可能会更好。一个例子是白喉毒素A。因此，申请人将尝试两种类型的代理商，并评估哪个是对前列腺癌基因治疗最有效：TK基因和DTA 基因，单独并与TK结合。这个建议的策略将是在细胞培养和动物模型中进行了测试。来自体外实验将确定所选的疗效和选择性自杀基因。有了这些基本知识，我们将感染肿瘤与我们的组织特异性启动子驱动的腺病毒一起使用SCID小鼠定义体内选择性和安全性的向量。