Stem Cell Derivation from Germ Cells

生殖细胞的干细胞衍生

• 批准号: 7055269
• 负责人: PETER John DONOVAN
• 金额: $ 24.94万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7055269
• 关键词: cell differentiation; cell growth regulation; cellular oncology; developmental genetics; fibroblast growth factor; gene expression; genetic regulation; genetically modified animals; germ cell neoplasms; germ cells; laboratory mouse; pluripotent stem cells; subtraction hybridization; tissue /cell culture

DESCRIPTION (provided by applicant): Correct development of Primordial Germ Cells (PGCs), the embryonic precursors of the gametes, is a prerequisite for adult fertility. Failure of PGCs to survive, proliferate or differentiate correctly in the embryo and fetus can result in sterility in the adult animal. In some cases normal PGC differentiation is perturbed and PGCs form pluripotent stem cells, termed Embryonal Carcinoma (EC) cells. These in turn form testicular tumors, teratomas or teratocarcinomas, which are the most common form of cancer in young men. Little is known about the molecular mechanisms responsible for guiding normal PGC differentiation and which are perturbed during testicular carcinogenesis. In vitro, PGCs cultured in the presence of Kit ligand (KL) and leukemia inhibitory factor (LIF) proliferate as long as they would in vivo. But when basic Fibroblast growth factor (bFGF or FGF2) is added, PGCs continue to proliferate and give rise to pluripotent stem cells termed Embryonic Germ (EG) cells. This process mimics the formation of testicular tumors in vivo in which PGCs give rise to pluripotent EC cells. Although EC and EG cells are pluripotent, our preliminary data show that PGCs cannot form any other cell type and are therefore considered nullipotent. Thus the conversion of a PGC into an EC or EG cell represents a conversion from a nullipotent to a pluripotent state. The ability to manipulate PGC potency in vitro with bFGF provides a unique system with which to study the control of developmental potency in mammals. We designed a novel retroviral gene transfer system to dissect and manipulate the signaling pathways activated in PGCs by KL, LIF and bFGF to determine the relative importance of these pathways in stem cell development. Understanding the molecular mechanisms controlling the conversion of a PGC into a pluripotent stem cell will fill gaps in our knowledge of developmental potency regulation, testicular tumor formation and germline development as well as generating general information about stem cell physiology. The Specific Aims of the proposal are: i) To determine the role of bFGF in altering developmental potential of PGCs, ii) To define the mode of action of bFGF in stem cell development, iii) To define the role of bFGF in pluripotent stem cell formation in vivo and iv) To identify genes up-regulated in PGCs following exposure to bFGF.

描述（由申请人提供）：配子的胚胎前体的原始生殖细胞（PGC）的正确发育是成人生育能力的先决条件。 PGC无法在胚胎和胎儿中正确地生存，增殖或分化，可能导致成年动物的不育。在某些情况下，正常的PGC分化会受到干扰，PGC形成多能干细胞，称为胚胎癌（EC）细胞。这些反过来又形成了睾丸肿瘤，畸胎瘤或畸胎瘤，这是年轻男性最常见的癌症形式。关于负责指导正常PGC分化并在睾丸癌发生过程中受到干扰的分子机制知之甚少。在体外，PGC在具有试剂配体（KL）和白血病抑制因子（LIF）存在下培养的PGC在体内增殖。但是，当添加基本成纤维细胞生长因子（BFGF或FGF2）时，PGC继续增殖并引起多能的干细胞，称为胚胎细胞（EG）细胞。该过程模仿体内睾丸肿瘤的形成，其中PGC会引起多能EC细胞。尽管EC和EG细胞是多能细胞的，但我们的初步数据表明，PGC不能形成任何其他细胞类型，因此被认为是无效的。因此，PGC转化为EC或EG细胞代表了从零叶剂到多能状态的转化。用BFGF在体外操纵PGC效力的能力提供了一个独特的系统，可以通过该系统研究哺乳动物中发育效力的控制。我们设计了一种新型的逆转录病毒基因转移系统，以剖析和操纵KL，LIF和BFGF在PGC中激活的信号通路，以确定这些途径在干细胞发育中的相对重要性。了解控制PGC转化为多能干细胞的分子机制将填补我们对发育效力调节，睾丸肿瘤形成和种系发育的了解，并生成有关干细胞生理学的一般信息。该提案的具体目的是：i）确定BFGF在改变PGCS的发育潜力中的作用，ii）定义BFGF在干细胞发育中的作用方式，iii）定义BFGF在VIVO中的多能干细胞形成中的作用，并在pGC中识别BFF的基因上调节的基因，以确定基因上调的基因。