Telomerase Transport and Targeting

描述（由申请人提供）：人类端粒酶，维持染色体末端端粒的核糖核蛋白酶，在大多数正常体细胞中不存在，在几乎所有癌细胞中都存在。端粒酶的激活诱导细胞永生化，对肿瘤的发生和发展至关重要。因此，抑制端粒酶活性为治疗几乎所有癌症提供了一个有希望的方法。为了合理设计有效的抑制剂，需要更好地了解端粒酶。在人类中，端粒酶包括两个对功能至关重要的亚基：RNA亚基（人类端粒酶RNA）和蛋白质亚基（人类端粒酶逆转录酶）。酶复合物在癌细胞中的组装位置和机制（可能指示端粒酶在何处以及如何靶向）尚不清楚。此外，鉴定端粒酶的其他基本成分将提供额外的潜在抑制靶点。本课题的主要目的是对细胞中端粒酶的运输和组装进行详细的了解，并开发一类基于rna的端粒酶抑制剂，有效地限制或阻止癌细胞的生长。体内分析将在非洲爪蟾卵母细胞（由于该系统的许多技术优势）和培养的人类细胞（包括原代和癌细胞系）中进行。为了实现我们的目标，我们确定了以下三个具体目标：目标1：研究体内功能性端粒酶的生物发生途径；目标2：研究正常细胞和癌细胞中关键人类端粒酶成分的定位和运输；目标3：开发能够阻止癌细胞生长的有效抗端粒酶核酶。

DESCRIPTION (provided by applicant): Human telomerase, the ribonucleoprotein enzyme that maintains telomeres at chromosome termini, is absent in most normal somatic cells and is present in nearly all cancer cells. Activation of telomerase induces cellular immortalization and is critical for the development and progression of tumors. Thus, inhibition of telomerase activity offers a promising approach for treating nearly all cancers. A better understanding of telomerase is needed to allow rational design of effective inhibitors. In humans, telomerase includes two subunits essential for function: an RNA subunit (human telomerase RNA) and a protein subunit (human telomerase reverse transcriptase). The location and mechanism of assembly of the enzyme complex in cancer cells (which may indicate where and how to target telomerase) is not known. Furthermore, identification of additional essential components of telomerase would provide additional potential targets for inhibition. The major objectives of this proposal are to obtain a detailed understanding of the trafficking and assembly of telomerase in cells, and to develop a class of RNA-based telomerase inhibitors effective at limiting or preventing the growth of cancer cells. In vivo analysis will be performed both in Xenopus oocytes (due to the many technical advantages of the system) and cultured human cells (including primary and cancer cell lines). To address our objectives we have defined the following three specific aims: Aim 1: To investigate the pathway of biogenesis of functional telomerase in vivo Aim 2: To examine the localization and trafficking of key human telomerase components in normal and cancer cells Aim 3: To develop efficacious anti-telomerase ribozymes capable of preventing growth of cancer cells.