Targeting TAK1 in Neuroblastoma

描述（由申请人提供）：神经母细胞瘤（NB）仍然是儿童最常见的颅外实体瘤。大多数高风险NB患者对治疗显示出初始反应，但最终复发，这表明获得性耐药性或耐药细胞的选择与化疗治疗一起发生。这是治疗的一大障碍。了解介导化疗耐药性的分子机制并靶向该途径中的关键分子对于治愈这种疾病至关重要。 NF-？B活化在肿瘤细胞中经常遇到，并且被认为是癌症化疗抗性的机制之一。化疗药物和放射治疗可激活NF-？B。TAK 1是IKK和MAPK激活以及响应多种刺激的IL-6基因表达的关键激酶中间体。最近，肿瘤和炎症细胞之间的相互作用已被报道有助于临床转移性NB表型。已发现NB细胞中的半乳糖凝集素-3依赖性途径上调人NB微环境中的IL-6。基质细胞和巨噬细胞中的IL-6表达促进肿瘤微环境中的NB增殖。TAK 1介导NF-？B和MAPK激活对遗传毒性应激的反应。鉴于NF-？B和MAPK激活是两种主要的存活信号，我们推测抑制TAK 1激活可能破坏细胞死亡和细胞存活之间的平衡，并使细胞对化疗敏感，导致细胞死亡。此外，基质细胞和肿瘤相关巨噬细胞中的TAK 1抑制可以阻断肿瘤诱导的IL-6表达，并破坏它们与肿瘤微环境中NB细胞的功能性相互作用。 在我们的初步研究中，我们已经发现，TAK 1抑制剂的小分子抑制剂（5 Z-7-oxozeaenol）显着提高NB细胞化疗的敏感性在体外和体内。这项工作的中心假设是TAK 1通过介导NB肿瘤细胞与肿瘤微环境中的基质细胞和肿瘤相关巨噬细胞的相互作用在NB的化疗耐药性中起重要作用。本实验将通过原位和TH-MYCN转基因小鼠模型分析TAK 1抑制剂对肿瘤耐药性和肿瘤微环境的影响来验证这一假设。本申请的具体目的是：1）在NB的原位异种移植和TH-MYCN转基因小鼠模型中确定TAK 1抑制剂是否使NB细胞对化疗敏感; 2）确定TAK 1抑制对这些模型中NB细胞和肿瘤微环境相互作用的影响。 拟议的项目将确立TAK 1作为NB的治疗靶点。此外，这种TAK 1激酶的小分子抑制剂可作为治疗高危NB患者的潜在辅助药物。该提案的长期目标是确定和验证潜在的可药用酶靶点，用于治疗儿童这种毁灭性疾病。

DESCRIPTION (provided by applicant): Neuroblastoma (NB) continues to be the most common extracranial solid tumor in children. The majority of high-risk NB patients show an initial response to therapy but ultimately relapse, suggesting that acquired drug resistance or selection of therapy-resistant cells occurs with chemotherapy treatment. This presents a major obstacle for treatment. Understanding the molecular mechanisms that mediate resistance to chemotherapy and targeting key molecules in this pathway are pivotal for curing this disease. NF-?B activation is frequently encountered in tumor cells and it is believed to be one of the mechanisms of cancer chemotherapy resistance. Chemotherapeutic agents and radiation therapy can activate NF-?B. TAK1 is a pivotal kinase intermediate for IKK and MAPK activations, as well as IL-6 gene expression in response to multiple stimuli. Recently, interactions between tumor and inflammatory cells have been reported to contribute to the clinical metastatic NB phenotype. A galectin-3-dependent pathway in NB cells has been found to upregulate IL-6 in the microenvironment of human NB. IL-6 expression in stromal cells and macrophages promotes NB proliferation in tumor microenvironment. TAK1 mediates NF-?B and MAPK activations in response to genotoxic stresses. Given that NF-?B and MAPK activations are two major survival signals, we hypothesize that inhibition of TAK1 activation may disrupt the balance between cell-death and cell-survival, and sensitize cells to chemotherapy resulting in cell death. Furthermore, TAK1 inhibition in stromal cells and tumor-associated macrophages may block tumor-induced IL-6 expression and disrupt their functional interaction with NB cells in tumor microenvironment. In our preliminary studies, we have found that TAK1 inhibition by a small molecule inhibitor (5Z-7-oxozeaenol) significantly enhances the sensitivity of NB cells to chemotherapy in vitro and in vivo. The central hypothesis of this work is that TAK1 plays an important role in chemoresistance of NB by mediating the interaction of NB tumor cells with stromal cells and tumor-associated macrophages in the tumor microenvironment. The proposed experiments will test this hypothesis by using an orthotopic and TH-MYCN transgenic mouse models to analyze the effect of TAK1 inhibitor on tumor chemoresistance and tumor microenvironment. The specific aims for this application are: 1) to determine whether TAK1 inhibitor sensitizes NB cells to chemotherapy in both orthotopic xenograft and TH-MYCN transgenic mouse models of NB; 2) to determine the effect of TAK1 inhibition on the interaction of NB cells and tumor microenvironment in these models. The proposed project, will establish TAK1 as a therapeutic target in NB. Furthermore, this small molecule inhibitor of TAK1 kinase may serve as a potential adjunct in the treatment of high-risk NB patients. The long-term goal of this proposal is to identify and validate potential druggable enzymatic targets for therapeutic intervention of this devastating disease in children.