NEUROTROPHIN AND TRK EXPRESSION IN MEDULLOBLASTOMA AND NEUROBLASTOMA

神经营养因子和 TRK 在髓母细胞瘤和神经母细胞瘤中的表达

• 批准号: 6219178
• 负责人: GARRETT M BRODEUR
• 金额: $ 2.33万
• 依托单位: CHILDREN'S HOSP OF PHILADELPHIA
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-05-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6219178
• 关键词: biological signal transduction; growth factor receptors; human tissue; immunocytochemistry; medulloblastoma; molecular oncology; monoclonal antibody; neuroblastoma; neurotrophic factors; pediatric neoplasm /cancer; polymerase chain reaction; receptor expression; tissue /cell culture

Neuroblastomas are neural crest derived tumors that express tyrosine kinase receptors encoded by TrkA, TrkB, and TrkC during development. These receptors bind to the neurotrophins NGF, BDNF, and NT-3, respectively. We have shown that favorable neuroblastoma express TrkA and TrkC, while unfavorable, N-myc amplified neuroblastomas express TrkB. In medulloblastomas, high expression of TrkC is associated with more favorable outcome. These studies have lead to our hypothesis that activation of TrkA and/or TrkC induces differentiation leading to a favorable outcome, while activation of TrkB is critical to the survival or growth of unfavorable tumors. Supporting this concept are studies in neuroblastoma that show a distinct difference in response to neurotrophin addition--favorable primary tumors respond to NGF by differentiation while BDNF promotes growth/ survival in cell lines. An important question raise by our hypothesis is how do different members of the Trk family promote the opposite fates of differentiation and growth. The goals of this proposal are to understand the roles of TrkB and TrkC in neuroblastoma and medulloblastoma pathogenesis and to elucidate the mechanism by which similar receptors promote different outcomes. Specifically, we will determine the role of TrkB receptors in unfavorable neuroblastomas by examining the signal transduction pathways in cell lines expressing endogenous TrkB. We will determine the activation patterns of the signaling intermediates, SHC, PI3 kinase, and PLC-gamma1, and determine if pathways involved in differentiation in PC12 cells--prolonged activation of ERK and phosphorylation of SNT--are induced by BDNF. We will determine whether the overexpression of TrkB or TrkC (expressed primarily in favorable tumors), mediates differentiation or cell growth. We will examine the role of TrkC receptors in favorable neuroblastomas by determining the effect of neurotrophin addition and withdrawal on primary cultures of favorable neuroblastomas. Signal transduction pathways will be examined when sufficient tissue is available. We plan to conduct parallel studies in medulloblastoma cell lines. We will determine the effect of BDNF and NT-3 and we will develop monoclonal antibodies that can specifically recognize TrkA, TrkB and TrkC by immunohistochemistry. The successful completion of these studies may provide important insights into the selective effects of activating the different Trk family receptors. Furthermore, our results should provide important information about the role of TrkB and TrkC in different subsets of neuroblastomas and medulloblastomas and medulloblastomas by their pattern of Trk expression may help predict outcome and guide therapy for these patients.

神经母细胞瘤是神经嵴衍生的肿瘤，表达 酪氨酸激酶受体由 TrkA、TrkB 和 TrkC 编码 发展。这些受体与神经营养因子 NGF、BDNF 结合， 和NT-3，分别。 我们已经证明了有利的 神经母细胞瘤表达TrkA和TrkC，而不表达N-myc 扩增的神经母细胞瘤表达 TrkB。 在髓母细胞瘤中，高 TrkC 的表达与更有利的结果相关。 这些研究得出我们的假设：TrkA 的激活 和/或 TrkC 诱导分化，从而产生有利的 结果，而 TrkB 的激活对于生存或生存至关重要 不利肿瘤的生长。 支持这一概念的是研究 神经母细胞瘤的反应表现出明显的差异 添加神经营养素——有利的原发肿瘤对 NGF 的反应 BDNF 促进细胞分化，同时促进细胞生长/存活 线。 我们的假设提出的一个重要问题是如何 Trk家族的不同成员推动了相反的命运 分化和成长。 该提案的目标是 了解 TrkB 和 TrkC 在神经母细胞瘤中的作用 髓母细胞瘤的发病机制并阐明其机制 相似的受体会促进不同的结果。 具体来说， 我们将确定 TrkB 受体在不利的情况下的作用 通过检查神经母细胞瘤的信号转导途径 表达内源性 TrkB 的细胞系。 我们将确定 信号中间体、SHC、PI3 的激活模式 激酶和 PLC-gamma1，并确定是否涉及通路 PC12细胞的分化——ERK和ERK的延长激活 SNT 的磷酸化--由 BDNF 诱导。 我们将确定 TrkB 或 TrkC 是否过度表达（主要表达于 有利的肿瘤），介导分化或细胞生长。 我们 将检查 TrkC 受体在有利的作用 通过确定神经营养蛋白添加的效果来检测神经母细胞瘤 并撤回有利神经母细胞瘤的原代培养物。 当足够时，将检查信号转导途径 组织是可用的。 我们计划开展平行研究 髓母细胞瘤细胞系。 我们将确定 BDNF 的效果 和 NT-3，我们将开发单克隆抗体 通过以下方式专门识别 TrkA、TrkB 和 TrkC： 免疫组织化学。 这些研究的顺利完成 可能为了解选择性效应提供重要见解 激活不同的 Trk 家族受体。 此外，我们的 结果应提供有关作用的重要信息 神经母细胞瘤不同亚型中的 TrkB 和 TrkC 髓母细胞瘤和髓母细胞瘤的 Trk 模式 表达可能有助于预测结果并指导这些疾病的治疗 患者。