Stem cell manipulation via HOX gene regulation

通过 HOX 基因调控进行干细胞操作

• 批准号: 7669125
• 负责人: STEPHEN G EMERSON
• 金额: $ 28.08万
• 依托单位: HAVERFORD COLLEGE
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-16 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7669125
• 关键词: Acute leukemia; Biochemical Genetics; Biological Assay; Biology; Blast Cell; CD34 gene; Cell Count; Cell Cycle; Cell Lineage; Cells; Data; Elements; Equilibrium; Gene Expression Regulation; Gene Targeting; Gene Transfer; Genes; Genetic Transcription; Hematology; Hematopoietic stem cells; Homeobox; Homeobox Genes; Homeodomain Proteins; Human; In Vitro; Investigational Therapies; JUN gene; Malignant Neoplasms; Measures; Mouse Strains; Mus; NOD/SCID mouse; Play; Proteins; Role; Stem cell transplant; Stem cells; System; Testing; Tissues; Transplantation; base; cancer therapy; improved; in vivo; oncology; overexpression; paralogous gene; research study; self-renewal; stem cell differentiation; stem cell therapy; transcription factor

DESCRIPTION (provided by applicant): Stem cell therapies play a major and increasing role in cancer therapies. The ability to expand stem cell numbers would have broad application in hematology and oncology. In addition, the ability to enforce stem cell differentiation could improve the therapy of many cancers, notably acute leukemias. Biochemical and genetic experiments in many systems indicate that homeobox proteins regulate the balance between stem cells and lineage-specific cells, in many tissues. We have recently found that the trimeric transcription factor NF-Y, which had been previously shown to regulate c-jun, p27 and CD34 transcription, is the key regulated transcription factor controlling the expression of HOXB4, as well as the paralogs HOXC4 and HOXD4. Enforced overexpression of NF-Ya, the inducible element of the trimer, in stem cells by retroviral gene transfer increases the expression of HOXB4, HOXC4, HOXD4, as well as hTERT, LEF-1 and several stem cell markers. NF-Ya overexpression in stem cells also increases stem cell numbers as assayed by competitive repopulation following stem cell transplantation, while inhibition of NF-Y activity decreases stem cell numbers and promotes terminal differentiation. Based upon these data, we hypothesize that NF-Y functions as a master switch, controlling the expression of several genes critical for stem cell cycling and proliferation, including homeobox and other genes. To explore and test this hypothesis, we propose to: 1) Measure the consequences of NF-Ya over/ and underexpression in hematopoietic stem cells, both in normal mice and mouse strains deficient in each of several candidate downstream NF-Y target genes; 2) test the ability of soluble TAT-NF-Ya protein to biochemically and reversibly activate NF-Y target genes and increase HSCs, as measured by transplantation in vivo; and 3) Test the ability of DN-NF-Ya, and TAT-DN- NF-Ya protein to differentiate primary AML blasts in vitro, and on NOD/SCID mice with human AML in vivo. These experiments will describe in detail the role of NF-Y in the biology of hematopoietic stem cells, and will develop two experimental therapies based directly on the biology of NF-Y, for both HSC expansion and HSC differentiation.

描述（由申请人提供）：干细胞疗法在癌症治疗中发挥着重要且日益重要的作用。扩大干细胞数量的能力将在血液学和肿瘤学中具有广泛的应用。此外，加强干细胞分化的能力可以改善许多癌症的治疗，特别是急性白血病。许多系统中的生化和遗传实验表明，同源异型盒蛋白调节许多组织中干细胞和谱系特异性细胞之间的平衡。我们最近发现，三聚体转录因子NF-Y，这已经被证明是调节c-jun，p27和CD 34的转录，是关键的调节转录因子控制HOXB 4的表达，以及旁系同源HOXC 4和HOXD 4。通过逆转录病毒基因转移，在干细胞中NF-Ya（三聚体的诱导元件）的强制过表达增加了HOXB 4、HOXC 4、HOXD 4以及hTERT、LEF-1和几种干细胞标志物的表达。干细胞中的NF-Ya过表达也增加干细胞数量，如通过干细胞移植后的竞争性再增殖所测定的，而抑制NF-Y活性降低干细胞数量并促进终末分化。基于这些数据，我们假设NF-Y作为主开关发挥作用，控制对干细胞循环和增殖至关重要的几个基因的表达，包括同源框和其他基因。为了探索和检验这一假设，我们提出：1）在正常小鼠和几种候选下游NF-Y靶基因中的每一种都缺乏的小鼠品系中，测量造血干细胞中NF-Ya过/和低表达的后果; 2）如通过体内移植测量的，测试可溶性TAT-NF-Ya蛋白生化地和可逆地激活NF-Y靶基因并增加HSC的能力;和3）测试DN-NF-Ya和TAT-DN- NF-Ya蛋白在体外和在具有人AML的NOD/SCID小鼠体内分化原代AML母细胞的能力。这些实验将详细描述NF-Y在造血干细胞生物学中的作用，并将开发两种直接基于NF-Y生物学的实验疗法，用于HSC扩增和HSC分化。