Stem Cell Selection & Expansion Via HOX Gene Activation

干细胞选择

• 批准号: 6321190
• 负责人: STEPHEN G EMERSON
• 金额: $ 29.6万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 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 2005-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6321190
• 关键词: SCID mouse; gene induction /repression; genetic promoter element; genetically modified animals; homeobox genes; stem cells; transcription factor

DESCRIPTION: (Applicant's Abstract) Stem cell therapies play a major and increasing role in cancer therapies. If we were able to isolate repopulating stem cells, expand them in vitro and genetically manipulate them prior to reinfusion, we would be able to explore many avenues of protective therapies, including expansion of stem cells for multi-cycle chemotherapy, protection of stem cells with chemotherapy resistance genes, and improvement in stem cell quality with DNA repair genes. Published studies indicate that the homeobox gene HOXB4 is expressed in primitive hematopoietic cells, and that its enforced expression induces stem cell symmetric cycling. Our preliminary data indicates that we have isolated the human HOXB4 gene and its promoter, and that we have isolated at least two transcription factors that activate this promoter in both leukemic cells and normal CD34+ cells. In addition, we have found that CD34+ cells activating a HOXB4 expression construct are substantially enriched in long term culture initiating cells (LTCIC). This proposal seeks to identify and stimulate the fraction of stem cells that are capable of self-renewal, as illustrated by their ability to transcribe the homeobox gene HOXB4. In particular, we propose to: 1) Test the Ability of the Activated HOXB4 Promoter to NOD/SCID Repopulating Cells following Xenotransplantation; 2) Identify the Transcription Factors Activating the HOXB4 Promoter at the HxRE-1 (NF-1) Site; and 3) Identify Additional More Distant Genetic Elements That Enhance the Activity of the HOXB4 Promoter In Vivo. Integrated together, these aims will define a new paradigm for the molecular identification and manipulation of stem cells for hematopoietic support and genetic modification. If successful, this model should be directly translatable to clinical practice in the future.

描述：（申请人的摘要）干细胞疗法发挥作用， 在癌症疗法中的作用增加。如果我们能够隔离再播种 干细胞在体外扩展，并在遗传上对其进行操纵 再灌注，我们将能够探索许多保护疗法的途径， 包括扩展干细胞进行多周期化疗，保护 具有化学疗法抗性基因的干细胞，干细胞的改善 DNA修复基因的质量。发表的研究表明，同源 基因HOXB4在原始造血细胞中表达，并强制执行 表达诱导干细胞对称循环。我们的初步数据指示 我们已经隔离了人类Hoxb4基因及其启动子，并且我们已经 隔离至少两个转录因子，这些因子激活了这两种启动子 白血病细胞和正常的CD34+细胞。此外，我们发现CD34+ 激活HOXB4表达构建体的细胞大大富含 长期培养引发细胞（LTCIC）。该建议旨在识别和 刺激能够自我更新的干细胞的比例 以其转录同源基因HOXB4的能力为例。在 特别是，我们建议：1）测试激活的HOXB4启动子的能力 在异种移植后点点头/scID重新流传细胞； 2）确定 在HXRE-1（NF-1）位点激活HOXB4启动子的转录因子； 3）确定更多更遥远的遗传元素，以增强 HOXB4启动子在体内的活性。整合在一起，这些目标将 定义用于分子鉴定和操纵茎的新范式 造血支持和遗传修饰的细胞。如果成功，这 将来，模型应直接转换为临床实践。