Molecular Mechanisms in the Treatment of Neuroblastoma

描述（申请人提供）：神经母细胞瘤（Neuroblastoma， NB）是儿童交感神经系统最常见的恶性肿瘤，起源于神经嵴。尽管目前积极的治疗策略采用自体骨髓移植强化清髓化疗，但大多数高风险（4期）NB患者死于疾病。为了改善这种疾病患者的预后，必须更好地了解治疗失败的基础以及NB细胞对化疗成功反应的机制。我们工作的主要目的是研究NB细胞死亡的调控。两个假设是我们调查的核心。首先，细胞凋亡缺陷是本病发病的关键。第二点是，治疗方法可以在了解NB的死亡机制如何有效参与的基础上开发。在目前的建议中，我们概述了一些研究，以扩大我们对NB细胞凋亡治疗调控的信号通路的理解。特别强调的是阿霉素（Dox）和依托泊苷（VP16）激活的信号。Dox和VP16目前用于NB的所有活性治疗方案。这项工作的方向是由最近的结果指导的，结果表明，NF-kappa:B激活是Dox杀死某些n型NB细胞所必需的，而在代表性的s型细胞系中，NF-KappaB激活是组成部分，支持细胞存活。拟议的实验将确定NF-kappa B活性的这些差异是否与S或n表型分化有根本联系。此外，我们将研究原发性NB肿瘤，以直接表征NF-KappaB在人类肿瘤组织中的活性。我们将定义介导Dox和vp16诱导的NF- kappaB反应的细胞机制，并使用异种移植模型验证NF- kb控制对Dox治疗反应的预测。这些目标的结果将导致理解如何根据NF-KappaB在患病细胞中的功能选择额外的药物来获得治疗优势（例如，更近距离靶向导致NFKappaB活性的途径的分子）。最后，我们将运用在上一个资助期内获得的关于NB细胞对含有促凋亡BH3蛋白的易感性的具体知识，进行原理验证实验，从而开发一种新的基于疾病选择性肽的治疗方法。

DESCRIPTION (provided by applicant): Neuroblastoma (NB), the most common malignant sympathetic nervous system tumor of childhood, arises from the neural crest. Despite current aggressive treatment strategies employing intensive myeloablative chemotherapy with autologous bone marrow transplantation, most patients with high risk (Stage 4) NB die of their disease. In order to improve the outcome for patients with this disease, the basis for treatment failures as well as mechanisms that underlie successful responses to chemotherapy in NB cells must be better understood. The primary objective of our work has been to study the regulation of cell death in NB. Two hypotheses are central to our investigation. The first is that defects in apoptosis are essential for the pathogenesis of this disease. The second is that treatments can be developed based on understanding how the death machinery in NB is effectively engaged. In the current proposal we outline studies to extend our understanding of the signaling pathways controlling the therapeutic regulation of apoptosis in NB. A particular emphasis is placed on signaling activated by Doxorubicin (Dox) and etoposide (VP16). Dox and VP16 are presently used in all active treatment protocols for NB. The direction for this work is guided by recent results showing both that NF-kappa:B activation is required for Dox to kill certain N-type NB cells while in representative S-type cell lines NF-KappaB activation is constitutive, supporting cell survival. Proposed experiments will determine whether these differences in NF-kappa B activity are fundamentally linked with S- or N-phenotypic differentiation. Moreover, we will study primary NB tumors to characterize NF-KappaB activity directly in human tumor tissue. We will define the cellular mechanisms that mediate the Dox and VP16-induced NF- kappaB response and verify the prediction that NF-KB governs the response to Dox therapy using xenograft models. The results from these objectives will lead to an understanding of how additional agents could be selected to gain therapeutic advantage (e.g. molecules that more proximally target the pathway causing NFKappaB activity) depending on NF-KappaB function in the diseased cells. Lastly, we will apply specific knowledge acquired during the last funding period pertaining to the susceptibility of NB cells to pro-apoptotic BH3 containing proteins in proof-of-principle experiments leading towards the development of a novel disease selective peptide-based treatment.