TARGET SPECIFIC GENE THERAPY OF PROSTATE CANCER

描述：(应聘者摘要)前列腺癌是首位 美国男性中的肿瘤。二十万个新病例将是 1994年确诊，导致38,000人死亡。到目前为止，还没有有效的 已经为晚期患者开发了治疗方法，尤其是 激素难治，疾病。新型治疗药物的发展 战略是最重要的。利用自杀基因选择性地 根除肿瘤细胞已经显示出希望。由肿瘤组织特异性驱动 启动子，这些基因可以在肿瘤中选择性转录 细胞，并随后造成它们的破坏。 申请人已经表征了一种前列腺组织特异性启动子， 来源于人类前列腺特异性抗原的5‘侧翼序列 (PSA)基因。这个启动子元件在PSA-中表现出很强的活性- 产生前列腺癌细胞，但不是在不产生PSA的细胞中。 由于绝大多数晚期患者的肿瘤细胞 前列腺癌产生PSA，利用PSA启动子驱动 仅在前列腺组织中的治疗性基因应该会减轻 对全身毒性的担忧，同时也非常有效。他有 将启动子活性提高四到五倍 巨细胞病毒(CMV)增强子上游。 同时，他分析了不同的传递载体，以最大限度地 基因转移到前列腺肿瘤细胞中，发现腺病毒 媒介具有显著的优势，因为它具有高度的传染性和 基因表达。他现在将创建一种腺病毒结构，它具有 自杀效应基因由CMV-PSA启动子驱动，希望 这将选择性地根除前列腺癌细胞。胸腺嘧啶核苷 激酶基因(TK)已经成功地用于治疗几个人 肿瘤。当转导TK的肿瘤细胞暴露于 更昔洛韦，DNA复制被破坏，细胞最终 被毁了。不幸的是，前列腺癌细胞复制缓慢， 可能对治疗性基因的作用不敏感，这种基因需要 活跃的细胞分裂。在这种情况下，一个直接裂解的自杀基因 活动可能会更好。白喉毒素A就是一个例子。 因此，申请人将尝试这两种类型的代理，并评估 前列腺癌最有效的基因治疗：TK基因和DTA 基因，单独或与TK联合使用。这一拟议的战略将是 在细胞培养和动物模型中都进行了测试。来自体外 实验将决定所选药物的有效性和选择性。 自杀基因。有了这些基础知识，我们就会感染肿瘤- 用我们的组织特异性启动子驱动的腺病毒携带SCID小鼠 载体来定义体内的选择性和安全性。

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.