The Role of PDGFR in Medulloblastoma Progression

PDGFR 在髓母细胞瘤进展中的作用

• 批准号: 7227904
• 负责人: TOBEY J. MACDONALD
• 金额: $ 25.75万
• 依托单位: CHILDREN'S RESEARCH INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2011-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7227904
• 关键词: Adhesions; Affect; Apoptosis; Biological Process; Blocking Antibodies; Brain; Cell Line; Cell Proliferation Regulation; Cell Surface Receptors; Cells; Child; Clinical; Commit; Computer Simulation; Cranial Irradiation; Data; Data Set; Development; Disease; Dose; Environment; Gene Expression; Genes; Goals; Growth; Growth Factor; Human; In Vitro; Infant; Malignant - descriptor; Malignant neoplasm of brain; Mediating; Mitogen-Activated Protein Kinases; Molecular; Morbidity - disease rate; Multipotent Stem Cells; Neoplasm Metastasis; Neural Crest; Neuraxis; Neurologic; Neurons; Numbers; Outcome; PDGFRA gene; PDGFRB gene; Pathogenesis; Pathway interactions; Patients; Pattern; Phenotype; Phosphorylation; Platelet Inhibitors; Platelet-Derived Growth Factor; Platelet-Derived Growth Factor Receptor; Play; Population; Protein Overexpression; Protein Tyrosine Kinase; Proteins; RNA; RNA Interference; Regulation; Reporting; Research; Research Personnel; Role; Signal Transduction; Signal Transduction Pathway; Small Interfering RNA; Stimulus; Structure; Survival Rate; Survivors; Testing; Therapeutic; Therapeutic Intervention; Thinking; Transfection; Tumor Biology; autocrine; base; cell growth; cell motility; design; experience; human PDGFA protein; in vivo; inhibitor/antagonist; mRNA Expression; medulloblastoma; migration; neoplastic cell; novel; novel therapeutics; outcome forecast; paracrine; precursor cell; prevent; protein activation; protein expression; receptor; response; tumor

DESCRIPTION (provided by applicant): Medulloblastoma is the most common malignant brain tumor in children. To approach the problem of effective therapy, the progression of human medulloblastoma must first be understood. We hypothesize that platelet-derived growth factor (PDGFR)-mediated signal transduction enhances tumor cell responses that promote the growth and metastatic spread of medulloblastoma, and have shown that (i) PDGFR is significantly overexpressed by metastatic medulloblastomas, (ii) inhibitors of medulloblastoma cell PDGFR activity decrease phosphorylation of the downstream signaling target, MAPK, alter gene expression, and decrease cell migration and survival and (iii) in silico analysis of 135 known pro-metastatic genes within independent datasets of microarray gene expression of medulloblastomas, only three genes, including DDGFR, demonstrated detectable mRNA expression in at least one third of all tumors analyzed and significant overexpression by metastatic tumors in each dataset. These data, combined with the preliminary data showing that both alpha (PDGFRA) and beta (PDGFRB) subtypes of the receptor are 1) expressed on the RNA and protein level by medulloblastoma tumors and cells, 2) sparsely expressed by normal brain, 3) activated in an autocrine and paracrine fashion in medulloblastoma cells, and 4) capable of inducing apoptosis of medulloblastoma cells in a dose-dependent manner following treatment with a selective inhibitor of PDGFR tyrosine kinase activity, suggest a mechanism by which PDGFR may be vital for medulloblastoma growth and progression. Thus, PDGFR is a potential novel target for therapeutic intervention. To test this hypothesis we will employ human medulloblastoma cell lines. We will (i) conduct comprehensive in vitro studies to determine the PDGFR signaling cascade and its effects on survival, proliferation, adhesion, migration and invasion, (ii) determine the key gene expression changes induced by PDGFR signaling in these cells, (iii) develop medulloblastoma cells with deficient PDGFR expression by inducible siRNA transfection specific for each PDGFR and determine the effect of inhibited expression and activity on survival, proliferation and migration in vitro and growth and metastasis in vivo, and (iv) determine the expression pattern of phosphorylated PDGFR protein and its correlation with metastasis and outcome in human medulloblastomas as a way to assess the potential clinical utility of PDGFR inhibitors for this disease

描述（由申请人提供）：髓母细胞瘤是儿童中最常见的恶性脑肿瘤。为了解决有效治疗的问题，必须首先了解人髓母细胞瘤的进展。我们假设血小板衍生生长因子（PDGFR）介导的信号转导增强了肿瘤细胞的反应，从而促进了髓母细胞瘤的生长和转移扩散，并且已经表明（i）PDGFR在转移性髓母细胞瘤中显著过表达，（ii）髓母细胞瘤细胞PDGFR活性的抑制剂降低了下游信号靶点MAPK的磷酸化，改变了基因表达，和减少细胞迁移和存活，和（iii）在成神经管细胞瘤的微阵列基因表达的独立数据集中的135个已知的促转移基因的计算机分析中，只有三个基因，包括DDGFR，在所有分析的肿瘤中的至少三分之一中证实了可检测的mRNA表达，并且在每个数据集中转移性肿瘤的显著过表达。这些数据与初步数据相结合，表明受体的α（PDGFRA）和β（PDGFRB）亚型1）由成神经管细胞瘤肿瘤和细胞在RNA和蛋白质水平上表达，2）由正常脑稀疏表达，3）在成神经管细胞瘤细胞中以自分泌和旁分泌方式激活，和4）在用PDGFR酪氨酸激酶活性的选择性抑制剂处理后能够以剂量依赖性方式诱导成神经管细胞瘤细胞凋亡，提示PDGFR可能对髓母细胞瘤生长和进展至关重要机制。因此，PDGFR是治疗干预的潜在新靶点。为了验证这一假设，我们将使用人髓母细胞瘤细胞系。我们将（i）进行全面的体外研究，以确定PDGFR信号级联及其对存活、增殖、粘附、迁移和侵袭的影响，（ii）确定这些细胞中PDGFR信号传导诱导的关键基因表达变化，（三）通过对每种PDGFR特异性的可诱导siRNA转染，开发PDGFR表达缺陷的髓母细胞瘤细胞，体外存活、增殖和迁移以及体内生长和转移，以及（iv）确定磷酸化PDGFR蛋白的表达模式及其与人髓母细胞瘤中转移和结果的相关性，作为评估PDGFR抑制剂对这种疾病的潜在临床效用的方法