Elucidating the molecular mechanisms that regulate stem cell numbers in vivo

阐明体内调节干细胞数量的分子机制

• 批准号: 8220768
• 负责人: Erika A Bach
• 金额: $ 35.39万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8220768
• 关键词: Ablation; Address; Biogenesis; Biological; Biological Process; Biology of Aging; Cancer Biology; Cancer Etiology; Cancer Patient; Cell Count; Cell Cycle; Cell Cycle Progression; Cells; Cyclin E; Data; Dissection; Drosophila genus; Embryo; Evolution; Eye; Family member; G1 Phase; Gene Targeting; Genes; Genetic; Genetic Epistasis; Growth; Health; Homeostasis; Homologous Gene; Human; Knowledge; Laboratory Research; Link; Maintenance; Mammals; Measures; Mediating; Metabolic; Methods; Mitosis; Molecular; Molecular Genetics; Mutation; Natural regeneration; Neoplasm Metastasis; Nuclear Protein; Organ; Organism; Pathway interactions; Pharmaceutical Preparations; Phase; Play; Process; Property; Protein Biosynthesis; Regenerative Medicine; Regulation; Role; Signal Transduction; Stem cells; System; Testis; Therapeutic Agents; Therapeutic Intervention; Tissues; c-myc Genes; cancer cell; cancer stem cell; cdc Genes; cell growth; cytokine; daughter cell; design; fly; in vivo; lymph nodes; nerve stem cell; novel; prevent; self-renewal; stem cell population; success; transcription factor; tumor; tumorigenesis; Ablation; Address; Biogenesis; Biological; Biological Process; Biology of Aging; Cancer Biology; Cancer Etiology; Cancer Patient; Cell Count; Cell Cycle; Cell Cycle Progression; Cells; Cyclin E; Data; Dissection; Drosophila genus; Embryo; Evolution; Eye; Family member; G1 Phase; Gene Targeting; Genes; Genetic; Genetic Epistasis; Growth; Health; Homeostasis; Homologous Gene; Human; Knowledge; Laboratory Research; Link; Maintenance; Mammals; Measures; Mediating; Metabolic; Methods; Mitosis; Molecular; Molecular Genetics; Mutation; Natural regeneration; Neoplasm Metastasis; Nuclear Protein; Organ; Organism; Pathway interactions; Pharmaceutical Preparations; Phase; Play; Process; Property; Protein Biosynthesis; Regenerative Medicine; Regulation; Role; Signal Transduction; Stem cells; System; Testis; Therapeutic Agents; Therapeutic Intervention; Tissues; c-myc Genes; cancer cell; cancer stem cell; cdc Genes; cell growth; cytokine; daughter cell; design; fly; in vivo; lymph nodes; nerve stem cell; novel; prevent; self-renewal; stem cell population; success; transcription factor; tumor; tumorigenesis

DESCRIPTION (provided by applicant): The molecular mechanisms controlling stem cell self-renewal versus differentiation hold great potential for advances in cancer biology, aging and regenerative medicine. Increasing the pool of stem cells provides a condition for oncogenesis; tumors have "cancer stem cells" that self-renew and establish metastases. A critical regulator of stem cell numbers in mammals is the JAK/STAT pathway. Inappropriate activation of mammalian JAKs and STATs cause cancer and inhibiting their activity blocks the growth of primary human cancer cells. These data suggests that developing drugs which specifically inhibit JAKs or STATs, could offer novel treatments for cancer patients. Despite these compelling observations, the mechanisms utilized by this pathway to regulate stem cell numbers in mammals have not yet been elucidated. Mammals have multiple jak and stat genes, making the analysis of their in vivo function difficult. Drosophila offers an ideal system to address this issue, as its control of stem cell numbers is conserved in several tissues, including the testis and eye. Drosophila has only one jak and one stat (called stat92E) and offers facile in vivo analysis. This application concerns the dissection of molecular mechanisms used by the JAK/STAT pathway to regulate stem cell number in Drosophila. Three distinct processes must occur in a coordinated manner for stem cell populations to be maintained: increase in cellular mass, mitosis and self-renewal. Since Stat92E is a transcription factor, discrete Stat92E target genes should mediate its effects on these processes. Three such genes with human homologs, cyclin E (cycE), dmyc and chinmo, appear to reside directly downstream of Stat92E. CycE is the rate-limiting regulator of the cell cycle and its expression is increased by Stat92E in a cell- autonomous manner. dMyc is the sole c-Myc family member in Drosophila and is a critical regulator of cellular growth. Stat92E increases protein synthesis and may act through dMyc to do so. chinmo encodes a novel nuclear protein and is regulated by Stat92E in a cell-autonomous manner. Like Stat92E, Chinmo is required within testis stem cells for their self-renewal. The identification of Stat92E-regulated targets with links to mitosis, cellular growth and self-renewal is a major advance in our understanding of the growth-regulatory properties of the JAK/STAT pathway. Aim 1 (Characterize the effects of JAK/STAT signaling on proliferation) employs molecular methods and FACS analysis to measure the effects of JAK/STAT signaling on proliferation rates, cell cycle phasing and expression of critical cell cycle factors. Aim 2 (Determine if Stat92E regulates cellular growth through dMyc) uses genetic approaches and FACS analysis to measure the effects of Stat92E on cellular growth and to determine if it regulates this process through dmyc. Aim 3 (Determine if Stat92E regulates self-renewal in through chinmo) uses genetic and molecular approaches to determine if Stat92E regulates self-renewal in testis stem cells through chinmo alone or through additional target genes. PUBLIC HEALTH RELEVANCE Due to evolution, JAK and STAT genes exist in very similar forms in other organisms, such as the fruit fly Drosophila. The fruit fly is an excellent genetic organism that has been used for many years in research laboratories and with great success to identify and characterize genes critical for basic biological processes. Our study is designed to eludicate how the JAK/STAT pathway regulates stem cell numbers in Drosophila.

描述（由申请人提供）：控制干细胞自我更新与分化的分子机制具有巨大的癌症生物学，衰老和再生医学的潜力。增加干细胞池为肿瘤发生提供了条件。肿瘤具有自我更新并建立转移酶的“癌干细胞”。哺乳动物中干细胞数的关键调节剂是JAK/STAT途径。哺乳动物JAKS和Stats的不当激活会导致癌症并抑制其活性，从而阻止了原发性人类癌细胞的生长。这些数据表明，开发专门抑制JAK或统计数据的药物可以为癌症患者提供新的治疗方法。尽管进行了这些引人注目的观察，但该途径使用的调节哺乳动物干细胞数的机制尚未阐明。哺乳动物具有多个JAK和STAT基因，使其体内功能的分析变得困难。果蝇提供了解决此问题的理想系统，因为其对干细胞数量的控制是在包括睾丸和眼睛在内的多个组织中保守的。果蝇只有一个JAK和一个Stat（称为STAT92E），并提供体内分析。该应用涉及JAK/STAT途径用于调节果蝇中干细胞数的分子机制的解剖。必须以协调的方式进行三种不同的过程才能维持干细胞种群：细胞质量，有丝分裂和自我更新的增加。由于STAT92E是转录因子，因此离散的STAT92E靶基因应介导其对这些过程的影响。三个具有人类同源物的基因，Cyclin E（Cyce），DMYC和Chinmo似乎直接驻留在STAT92E的下游。 Cyce是细胞周期的限速调节剂，其表达通过STAT92E以细胞自主的方式增加。 DMYC是果蝇中唯一的C-MYC家族成员，是细胞生长的关键调节剂。 STAT92E增加了蛋白质的合成，并可能通过DMYC起作用。 Chinmo编码一种新型的核蛋白质，并以细胞自动方式受到STAT92E的调节。像STAT92E一样，睾丸干细胞中需要Chinmo才能自我更新。通过与有丝分裂，细胞生长和自我更新联系的STAT92E调节靶标的鉴定是我们对JAK/STAT途径的生长调节特性的重大进步。 AIM 1（表征JAK/Stat信号对增殖的影响）采用分子方法和FACS分析来测量JAK/STAT信号对增殖速率，细胞周期相位和关键细胞周期因子的表达的影响。 AIM 2（确定STAT92E是否通过DMYC调节细胞生长）使用遗传方法和FACS分析来衡量Stat92E对细胞生长的影响，并确定它是否通过DMYC调节了这一过程。 AIM 3（确定STAT92E是否通过Chinmo调节自我更新）使用遗传和分子方法来确定STAT92E是否单独或通过其他靶基因来调节睾丸干细胞中的自我更新。 由于进化而引起的公共卫生相关性，JAK和Stat基因在其他生物（例如果蝇果蝇）中以非常相似的形式存在。果蝇是一种出色的遗传生物，在研究实验室中已经使用了多年，并取得了巨大的成功，以识别和表征对基本生物学过程至关重要的基因。我们的研究旨在避免JAK/STAT途径如何调节果蝇中的干细胞数量。