OVERCOMING CELLULAR SENESCENCE IN HUMAN EPITHELIAL CELLS

拟议项目的主要目标是研究人类是如何 上皮细胞变得永生。细胞永生是一件重要的事情 癌变的发展，以上皮细胞为主 人类癌症。需要检验的假设是，废除 视网膜母细胞瘤途径和端粒酶的激活是 上皮细胞克服衰老。通过使用独特的上皮细胞模型 在实验室开发的系统中，PI建议识别因素 在衰老过程中参与Rb通路的诱导，并确定如何 当细胞变得永生时，端粒酶被激活。终端的作用 Rb通路的激活和衰老的差异将被研究 通过几种途径，包括调控p16INK4a的表达，a CDK4/Cyclin D抑制剂，在特异性丢失的上皮细胞中 P16INK4a在hTERT永生化过程中的表达 端粒酶。参与p16INK4a上调的基因也将被发现。 通过使用逆转录病毒文库绕过Rb介导的阻断。因为 PI观察到，p16INK4a在人类癌症中通常缺失表达 这项工作可能会大大增加我们对 癌症发生的早期阶段。此前的研究表明，人类 乳头瘤病毒E6激活端粒酶。为了确定这一现象的机制 激活，将使用差异激活端粒酶的HPV E6突变体 在基因表达阵列分析和酵母双杂交筛选中鉴定 HPV E6激活端粒酶的相关因素。了解E6如何 激活端粒酶将有助于阐明端粒酶是如何激活的 总体而言。国际和平研究所注意到，这些研究有可能导致 预防、诊断和治疗艾滋病的新战略和创新战略 人类癌症。这项提案的总体目标是研究人类是如何 上皮细胞永生，这是发展中的一个关键事件 恶毒。这一提议的核心假设是，废除 视网膜母细胞瘤途径和端粒酶的激活是 上皮细胞克服衰老。通过使用独特的上皮细胞模型 在他的实验室开发的系统PI将追求以下具体 目的：(1)确定分化在Rb介导的细胞衰老中的作用。 人上皮细胞；(2)鉴定和鉴定上游基因 参与Rb介导的人上皮细胞衰老；以及 (3)探讨HPV16E6对上皮细胞端粒酶活性的影响。这些 研究应该具有导致新的和创新的战略的潜力 用于预防、诊断和治疗人类癌症。

The major goal of the proposed project is to study how human epithelial cells become immortal. Cellular immortalization is a key event in the development of malignancy, and epithelial cells give rise to the majority of human cancers. The hypothesis to be tested is that both the abrogation of the retinoblastoma pathway and activation of telomerase is necessary for epithelial cells to overcome senescence. By using unique epithelial cell model systems developed in the laboratory, the PI proposes to identify factors involved in the induction of the Rb pathway during senescence and determine how telomerase is activated as cells become immortal. The role of terminal differentiation in activation of the Rb pathway and senescence will be examined by several approaches, including regulated expression of p16INK4a, a cdk4/cyclin D inhibitor, in epithelial cells that have specifically lost p16INK4a expression upon immortalization with hTERT, the catalytic component of telomerase. Genes involved in upregulation of p16INK4a will also be identified by using cDNA retroviral libraries to bypass the Rb mediated block. Because expression of p16INK4a is commonly lost in human cancers, the PI observes that this work is likely to lead to a significant increase in our understanding of the early stages of carcinogenesis. Previous studies demonstrated that human pappiloma virus E6 activates telomerase. To determine the mechanism of this activation, HPV E6 mutants that differentially activate telomerase will be used in cDNA expression array analysis and yeast two-hybrid screens to identify factors involved in telomerase activation by HPV E6. Understanding how E6 activates telomerase will be useful in elucidating how telomerase is activated in general. The PI observes that these studies have the potential of leading to new and innovative strategies for the prevention, diagnosis and treatment of human cancer. The overall goal of this proposal is to study how human epithelial cells become immortal, which is a key event in the development of malignancy. The hypothesis central to this proposal is that both abrogation of the retinoblastoma pathway and activation of telomerase are necessary for epithelial cells to overcome senescence. By using unique epithelial cell model systems developed in his laboratory the PI will pursue the following specific aims: (1) to determine the role of differentiation in Rb-mediated senescence of human epithelial cells; (2) to identify and characterize upstream genes involved in induction of Rb-mediated senescence in human epithelial cells; and (3) to determine how HPV 16 E6 activates telomerase in epithelial cells. These studies should have the potential of leading to new and innovative strategies for the prevention, diagnosis and treatment of human cancer.