A Myc-centered network in embryonic stem cells and somatic cell reprogramming

描述（由申请人提供）：我的长期职业目标是成为一名独立的干细胞研究人员，进一步了解控制胚胎干细胞（ES）和诱导多能干细胞（iPS）自我更新和分化的转录调控机制。“独立之路奖（K99/R 00）”将极大地支持我成为一个完全独立的调查员，不仅提供资金，而且还提供额外的培训机会。我的近期职业目标在指导阶段的指导下博士。Orkin首先扩展了我的技能和知识，以设计和执行解决干细胞研究中关键问题的实验，其次，通过与其他研究人员的交流扩大了我在该领域的兴趣。波士顿儿童医院和哈佛医学院除了提供独特的研究环境外，还提供各种培训课程。这些机构的优秀资源将帮助我实现我提出的研究目标，并让我在指导阶段得到适当的培训。Myc是用于产生iPS细胞的四种转录因子（Oct 4、Sox 2、Klf 4和Myc）之一，并且由于其在重编程过程中的双重作用而成为感兴趣的蛋白质; Myc的再活化在由iPS细胞产生的嵌合动物中显示出增加的致瘤性，但是在Myc不存在的情况下，IPS细胞产生的效率降低了几百倍。这些观察结果清楚地表明Myc在促进直接重编程中的关键作用，然而Myc在此过程中的分子机制尚未得到解决。我们的初步研究表明，Myc在ES细胞中有许多相互作用的蛋白质，包括组蛋白修饰酶。我们认为Myc通过与其相互作用的蛋白质促进重编程效率的提高。为了了解Myc及其相互作用蛋白的分子机制，我提出了以下具体的建议：1）在小鼠ES细胞中鉴定以Myc为中心的调控网络。2)鉴定参与Myc中心网络功能的表观遗传特征。3)测试Myc为中心的调控网络中每个因子的体细胞重编程潜力。该提案的目标是了解以Myc为中心的网络的分子机制，并开发在没有致癌Myc的情况下有效生成IPS细胞的替代方法。 相关性：从拟议的研究中获得的知识将扩大我们对Myc为中心的机制控制ES细胞的多能性和体细胞重编程过程的理解。这些信息将有助于通过使用ES细胞和/或IPS细胞开发患者特异性干细胞疗法。此外，这项研究产生的数据将是了解Myc在其他研究领域（如癌症和成体干细胞）中作用的宝贵资源。

DESCRIPTION (provided by applicant): My long-term career goal is to become an independent stem cell researcher pursuing further understanding of transcriptional regulatory mechanisms controlling self-renewal and differentiation in embryonic stem (ES) cells as well as induced pluripotent stem (iPS) cells. The 'Pathway to Independence Award (K99/R00)' will greatly support me to become a fully independent investigator by providing not only funding but also additional training opportunities. My immediate career goals during the mentored phase under the guidance of Dr. Stuart H. Orkin are first to expand my skills and knowledge to design and perform experiments addressing critical questions in stem cell research, and second, to broaden my interests in the field by communication with other researchers. The Children's Hospital Boston and Harvard Medical School provide a variety of training programs in addition to a unique research environment. The outstanding resources of these institutions will help me to accomplish my proposed research aims and allow me to have proper training during the mentored phase. Myc is one of the four transcription factors (Oct4, Sox2, Klf4, and Myc) used in generation of iPS cells and Is a protein of interest due to its dual roles In the reprogramming process; reactivation of Myc In the chimeric animals generated by iPS cells showed Increased tumorigenicity, but in the absence of Myc the efficiency of IPS cell generation was reduced by several hundred fold. These observations clearly imply the critical roles of Myc in facilitating direct reprogramming, however the molecular mechanisms of Myc In this process have not been addressed. Our preliminary studies suggest that Myc has many interacting partner proteins In ES cells including histone modifying enzymes. We propose that Myc promotes increased efficiency of reprogramming through the proteins with which it interacts. To understand molecular mechanisms of Myc and its interacting partner proteins, I propose the following Specific Alms: 1) Identification of the Myc-centered regulatory network in mouse ES cells. 2) Identification of epigenetic signatures involved in the function of the Myc-centered network. 3) Testing somatic cell reprogramming potential of each factor In Myc-centered regulatory network. The goals of this proposal are to understand the molecular mechanisms of the Myc-centered network and to develop alternative ways of efficient generation of IPS cells without oncogenic Myc. Relevance: The knowledge acquired from the proposed research will expand our understanding of a Myc-centered mechanism controlling pluripotency in ES cells, and somatic cell reprogramming process. This Information will facilitate development of patient-specific stem cell therapy by using ES cells and/or IPS cells. In addition, the data generated from this research will be a valuable resource for the understanding of roles of Myc in the other research areas, such as cancer, and adult stem cells.