Dynamics of cellular senescence in single human cells

描述（由申请人提供）：本提案的目标是研究单个人类细胞衰老的时间和控制。衰老是一种永久性的细胞周期停滞状态，是对肿瘤进展的内在防御。利用衰老来获得治疗效果将需要更好地理解基本的衰老生物学，新的实验工具来研究单细胞分辨率的表型，以及计算方法来理解细胞如何整合多种衰老信号。该提案为Jeremy Purvis博士提供了一个职业过渡计划，这将使他获得在单细胞分辨率下研究衰老所必需的额外培训，并为开发在应激反应有缺陷的细胞中诱导过早衰老的治疗方法奠定基础。在该奖项的指导阶段（K99），他将开发一种活细胞成像系统，用于实时监测DNA损伤诱导的衰老，并使用该系统确定肿瘤抑制因子p53的上游信号如何控制衰老标志物的表达（Aim 1）。这一关键阶段的培训将由Galit Lahav博士和Peter Sorger博士（哈佛医学院）共同监督，他们都是延时显微镜和细胞命运决定过程方面的专家。在向独立过渡（K99/R00）期间，他将确定启动关键衰老调控因子p16INK4a表达的转录调控因子，并表征这一过渡的动力学（Aim 2）。实现独立性（R00）的最后一步将涉及转移这些工具和概念来研究原代细胞系的衰老，特别关注如何整合多个信号以实现衰老决策（目标3）。这个三阶段过渡计划将阐明我们对细胞衰老的基本理解，并为识别诱导癌细胞过早衰老的疗法提供可扩展的计算/实验平台。这些目标与nims的主要目标高度一致，即支持促进人类疾病治疗和预防的基础发现。

DESCRIPTION (provided by applicant): The goal of this proposal is to investigate the timing and control of cellular senescence in single human cells. Senescence is a state of permanent cell cycle arrest and an inherent defense against tumor progression. Exploiting senescence for therapeutic gain will require a better understanding of basic senescence biology, novel experimental tools to study the phenotype at single-cell resolution, and computational approaches to understand how cells integrate multiple senescence signals. This proposal provides a career transition plan for Dr. Jeremy Purvis that will equip him with the additional training necessary to study senescence at single-cell resolution and form the foundation for developing treatments that induce premature senescence in cells with defective stress responses. During the mentored phase of the award (K99), he will develop a live-cell imaging system for monitoring DNA damage-induced senescence in real time and use this system to determine how upstream signaling of the tumor suppressor p53 control expression of senescence markers (Aim 1). This critical phase of training will be co-supervised by Dr. Galit Lahav and Dr. Peter Sorger (Harvard Medical School), who are both experts in time-lapse microscopy and cell fate decision processes. During the transition to independence (K99/R00), he will identify transcriptional regulators that initiate expression of the key senescence regulato p16INK4a and characterize the dynamics of this transition (Aim 2). The final step in achieving independence (R00) will involve transferring these tools and concepts to study senescence in primary cells lines, focusing specifically on how multiple signals are integrated to achieve a senescence decision (Aim 3). This three-phase transition plan will illuminate our basic understanding of cellular senescence and provide an extensible computational/experimental platform for identifying therapies that induce premature senescence in cancer cells. These aims are highly congruent with the NIGMS's primary goal of supporting basic discoveries that advance the treatment and prevention of human disease. PUBLIC HEALTH RELEVANCE: Cellular senescence is a natural biological process that prevents cells from dividing; in some cases, senescence stops the progression of cancer. The goal of this project is to understand how individual cells enter senescence by observing this transition in real time.