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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）前列腺癌是前列腺癌的主要病因。美国男性的肿瘤将有20万新病例 1994年确诊，导致38,000人死亡。到目前为止，没有有效的已经开发了用于晚期患者的治疗，特别是激素抵抗性疾病新型治疗药物的开发战略至关重要。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细胞中选择性地转录。细胞，并随后导致其破坏。申请人已经表征了前列腺组织特异性启动子，衍生自人前列腺特异性抗原的5'侧翼序列 (PSA)基因该启动子元件在PSA中显示出强活性。产生前列腺癌细胞，但不产生PSA的细胞。由于绝大多数晚期乳腺癌患者的肿瘤细胞前列腺疾病产生PSA，利用这种PSA促进剂来驱动前列腺组织中的治疗性基因可以减轻对全身毒性的担忧，同时非常有效。他将启动子活性提高了四到五倍，巨细胞病毒（CMV）增强子上游。同时，他分析了不同的交付载体，基因转移到前列腺肿瘤细胞，并发现腺病毒载体由于其高感染性而提供了显著的优势，基因表达。他现在将创建一个腺病毒结构，由CMV-PSA启动子驱动的自杀效应基因，希望这将选择性地根除前列腺肿瘤细胞。胸苷激酶基因（TK）已成功地用于治疗几种人类肿瘤。当用TK转染的肿瘤细胞暴露于更昔洛韦，DNA复制被破坏，细胞最终摧毁. 不幸的是，前列腺癌细胞复制缓慢，可能不容易受到治疗基因的作用，活跃的细胞分裂在这种情况下，一个自杀基因与直接裂解活动可能会更好。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人，并评估哪一种是最有效的前列腺癌基因治疗：TK基因和DTA 基因，单独和与TK组合。这一战略将是在细胞培养和动物模型中进行了测试。从体外实验将确定所选择的药物的功效和选择性，自杀基因有了这些基本知识，我们就能感染肿瘤- 携带我们的组织特异性启动子驱动的腺病毒的SCID小鼠载体来定义体内选择性和安全性。