REPLICATIVE SHORTENING OF TELOMERES IN HUMAN CELLS

染色体末端是专门的核蛋白结构，称为 端粒，这是稳定的染色体维护所必需的。损失 端粒重复，观察到在大多数正常体细胞研究， 日期，已被提出作为其复制的限制因素 寿命在肿瘤来源的细胞系中，端粒由端粒的转录因子维持。 核糖核蛋白酶端粒酶或其他，了解甚少 机制等建议调查个人的作用 端粒和端粒酶在复制性衰老和 使用新的方法使人成纤维细胞和淋巴细胞永生化 定量荧光原位杂交（FISH）程序 由申请人开发。此外，修改后的FISH程序将 以衡量复制的历史和潜力， 流式细胞术检测淋巴细胞。为此，淋巴细胞 来自正常个体、骨髓移植后患者的（亚）群体 移植和感染艾滋病毒的患者将进行分析， 和体外扩增后。该项目的具体目标是： 1.为了研究端粒长度在个体染色体上的变化， 人成纤维细胞和淋巴细胞克隆的增殖和衰老。 2.为了研究染色体上的端粒， 与端粒酶表达的关系。3.制定和完善方法， 测量细胞和染色体中的端粒重复序列。总的来说， 拟议中的研究将描述单个端粒在 人类细胞的复制衰老和永生化， 探索使用端粒长度测量作为评估 细胞的复制历史和潜力。

Chromosome ends are specialized nucleoprotein structures called telomeres, which are essential for stable chromosome maintenance. Loss of telomere repeats, observed in most normal somatic cells studied to date, has been proposed as the limiting factor in their replicative life-span. In tumor-derived cell lines, telomeres are maintained by the ribonucleoprotein enzyme telomerase or by other, poorly understood mechanisms. It is proposed to investigate the role of individual telomeres and telomerase in both the replicative senescence and immortalization of human fibroblasts and lymphocytes using novel quantitative fluorescence in situ hybridization (FISH) procedures developed by the applicant. In addition, modified FISH procedures will be explored to measure the replicative history and potential of lymphocytes by flow cytometry. For this purpose, lymphocyte (sub)populations from normal individuals, patients after bone marrow transplantation and patients infected with HIV will be analyzed before and after in vitro expansion. The specific aims of this project are: 1. To study the telomere length on individual chromosomes during propagation and senescence of human fibroblasts and lymphocyte clones. 2. To study telomeres on individual chromosomes in immortal cells in relation to telomerase expression. 3. To develop and refine methods to measure telomere repeats in cells and chromosomes. Taken together, the proposed research will delineate the role of individual telomeres in the replicative senescence and immortalization of human cells and explore the use of telomere length measurements as a tool to assess the replicative history and potential of cells.