Telomerase Transport and Targeting

描述（由申请人提供）：人端粒酶是一种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，但在几乎所有癌细胞中存在。端粒酶的激活诱导细胞永生化，并且对肿瘤的发展和进展至关重要。因此，抑制端粒酶活性为治疗几乎所有癌症提供了一种有前途的方法。为了合理设计有效的抑制剂，需要对端粒酶有更好的了解。在人类中，端粒酶包括两个对功能至关重要的亚基：RNA亚基（人端粒酶RNA）和蛋白质亚基（人端粒酶逆转录酶）。癌细胞中酶复合物的组装位置和机制（这可能表明在何处以及如何靶向端粒酶）尚不清楚。此外，鉴定端粒酶的另外的必需组分将提供另外的潜在抑制靶标。该提案的主要目标是详细了解细胞中端粒酶的运输和组装，并开发一类有效限制或阻止癌细胞生长的基于RNA的端粒酶抑制剂。将在非洲爪蟾卵母细胞（由于该系统的许多技术优势）和培养的人细胞（包括原代细胞系和癌细胞系）中进行体内分析。为了解决我们的目标，我们定义了以下三个具体目标：目的1：研究体内功能性端粒酶的生物合成途径目的2：研究正常细胞和癌细胞中关键的人端粒酶组分的定位和运输目的3：开发能够阻止癌细胞生长的有效的抗端粒酶核酶。

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.