Determination of Musashi1/CD44v6 signaling in mesenchymal glioma stem cells

间充质胶质瘤干细胞中 Musashi1/CD44v6 信号传导的测定

• 批准号: 8785106
• 负责人: Ichiro Nakano
• 金额: $ 10.07万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8785106
• 关键词: Adult; Affect; Attenuated; Binding; Biological Process; Brain Neoplasms; CD44 gene; Cell Survival; Cell model; Cells; Clinical; Cytotoxic Chemotherapy; Data; Development; Disease; Employee Strikes; Exhibits; Exons; Frequencies; Genes; Genetic; Glioblastoma; Glioma; Goals; Growth; Health; Histopathology; In Vitro; Maintenance; Malignant Neoplasms; Mediating; Mesenchymal; Modeling; Molecular; Mus; Patients; Phenotype; Phosphotransferases; Play; Population; Pre-Clinical Model; Primary Brain Neoplasms; Proteins; RNA Splicing; RNA-Binding Proteins; Radiation; Radiation therapy; Radioresistance; Recurrence; Regulation; Relapse; Resistance; Role; Route; Signal Transduction; Small Interfering RNA; Stem cells; Testing; Transcript; Transgenic Organisms; Translations; cancer cell; cancer stem cell; cell growth; chemoradiation; chemotherapy; conventional therapy; effective therapy; in vivo; nerve stem cell; novel; novel therapeutics; outcome forecast; overexpression; palliative; pre-clinical; radioresistant; research study; self renewing cell; small hairpin RNA; stemness; targeted treatment; temozolomide; therapeutic target; therapy resistant; tumor; tumor growth

DESCRIPTION (provided by applicant): Glioblastoma (GBM) remains among the most formidable cancers to treat, and current therapies, including radiation and temozolomide chemotherapy, have only palliative effects. Tumor recurrence occurs in virtually all patients, and relapsed tumors are more resistant to current cytotoxic therapies. Recent robust transcriptional profiling has classified GBM into 4 subtypes with distinct clinical features. In particular, mesenchymal (MES) GBM appears to be the most common subtype with the poorest prognosis. Nonetheless, the mechanisms that regulate growth of MES GBM cells have not been clarified. Among the heterogeneous cells in tumors, glioma stem cells (GSCs) are one of the, if not the only, critical therapeutic targets; however, subtype-specific GSCs are poorly characterized. Our preliminary data suggest the following: a- mesenchymal, but not proneural, GSCs express CD44v6; b- siRNA for CD44v6 reduces in vitro growth of MES, but not PN GSCs; c- CD44v6(+) cells but not CD44v6 (-) cells in mesenchymal GSCs express the neural stem cell-associated gene MELK; d- siRNA for CD44v6 reduces MELK expression; e- CD44 locus exhibits multiple Musashi 1 (Msi1)-binding sequences; f- shRNA- mediated Msi1 depletion diminishes CD44 expression and negatively affects splicing of exon v6. To achieve the goals of this study, we established and characterized patient-derived GBM sphere cultures and created patient-derived mouse GBM tumor models that recapitulate the histopathology of the original tumors. With these pre-clinical models, we will test the hypothesis that the Msi1-CD44v6 signaling is required for the growth and survival of therapy-resistant mesenchymal glioblastoma. Specifically, in Aim 1, we will test the hypothesis that CD44v6 is functionally essential for the proliferation of MES GSCs through signal interaction with MELK. In Aim 2, we will determine whether CD44 transcripts are a direct target of the RNA-binding protein Msi1 in GBM and if Msi1 via the axis CD44v6-MELK plays a role in radio-resistance.

描述（由申请人提供）：胶质母细胞瘤（GBM）仍然是治疗最强大的癌症之一，当前的疗法（包括放射线和替莫唑胺化疗）仅具有姑息性作用。 肿瘤复发发生在几乎所有患者中，复发性肿瘤对当前的细胞毒性疗法具有更抗性。 最近的鲁棒转录分析已将GBM分为具有不同临床特征的4个亚型。 特别是，间充质（MES）GBM似乎是最常见的亚型，预后最差。 但是，尚未阐明调节MES GBM细胞生长的机制。 在肿瘤中的异质细胞中，神经胶质瘤干细胞（GSC）是关键的治疗靶标之一，即使不是唯一的靶标。但是，亚型特异性GSC的特征较差。 我们的初步数据提出了以下内容：a-间充质，但不是胸膜，GSCS表达CD44V6； b- siRNA用于CD44V6可降低MES的体外生长，而不是PN GSC； c-CD44V6（+）细胞，但不是间充质GSC中的CD44V6（ - ）细胞表达神经干细胞相关的基因MELK； D- siRNA用于CD44V6可降低MELK表达； e-CD44基因座表现出多个musashi 1（MSI1）结合序列； F- shRNA介导的MSI1耗竭会减少CD44的表达，并对外显子V6的剪接产生负面影响。 为了实现这项研究的目标，我们建立了并表征了患者衍生的GBM球体培养物，并创建了患者衍生的小鼠GBM肿瘤模型，以概括原始肿瘤的组织病理学。 通过这些临床前模型，我们将测试以下假设：MSI1-CD44V6信号对于耐药性间质胶质母细胞瘤的生长和存活需要必需。 具体而言，在AIM 1中，我们将测试以下假设：CD44V6通过与MELK的信号相互作用通过信号相互作用而在功能上至关重要。 在AIM 2中，我们将确定CD44转录本是否是GBM中RNA结合蛋白MSI1的直接靶标，以及是否通过Axis CD44V6-MELK MSI1在放射性抗性中起作用。