Optimizing Pro-Apoptotic Therapeutics With Kinase Inhibition in Neuroblastoma

描述（由申请人提供）： 神经母细胞瘤（NB）是小儿常见的高致死性实体瘤。大多数患者存在高风险特征，并且由于肿瘤细胞凋亡途径的失能而死于化疗耐药疾病。Bcl 2同源结构域或BH蛋白（如Bcl 2、Mcl 1、巴克和Bax）通过介导线粒体对激活特异性促死亡BH 3蛋白的应激物的反应，在很大程度上控制细胞对化疗的反应。许多肿瘤类型依赖于改变BH蛋白相互作用的生存。我们的初步数据表明，NB异质性表达Mcl 1和Bcl 2，可能通过隔离活性BH 3死亡信号来防止细胞凋亡。此外，BH 3模拟肽模仿BHS-唯一的蛋白质的死亡结构域，在体外和体内都有效地诱导NB凋亡。稳定肽二级结构的新型化学修饰提高了血清的稳定性和效力。我们建议利用NB中失调的细胞凋亡途径的知识来设计合理的促死亡治疗策略，其目的如下：1）确定BH蛋白：导致NB中异常线粒体细胞凋亡的蛋白质相互作用; 2）评估化学修饰的BH 3结构域肽的功效和效力体外和体内针对NB细胞系;和3）证明当与靶向介导神经母细胞瘤中存活、增殖和化学反应的受体的酪氨酸激酶抑制剂组合时，BH 3肽在这些模型中的效力提高。 该提案提出了一个为期5年的研究和培训计划，将帮助主要研究者过渡到成为一名独立研究人员，最终目标是成为R 01资助的医生科学家。她的导师和顾问是细胞凋亡，神经母细胞瘤和实验治疗领域的领导者。她将利用费城儿童医院和宾夕法尼亚大学提供的充足资源来促进她的职业发展。 本案无关神经母细胞瘤是一种高度致命的肿瘤，复发后没有治愈性治疗。目前的治疗方法是无效的，新的治疗方法取决于靶向肿瘤特异性生物学的疗法的鉴定。BH 3肽，有效地杀死NB和其他癌细胞证明有希望作为翻译促死亡治疗剂，最近的新的化学修饰，以改善肽结构。将BH 3肽与临床上可用的激酶抑制剂组合证明，使用合理选择的药剂靶向存活信号传导和细胞凋亡两者将提供治疗对当前常规治疗方式具有抗性的癌症的新颖且有效的方法。

DESCRIPTION (provided by applicant): Neuroblastoma (NB) is a common pediatric solid tumor with high lethality. Most patients present with high-risk features and succumb to chemoresistant disease due to disabled tumor apoptosis pathways. Bcl2 homology-domain, or BH, proteins (such as Bcl2, Mcl1, Bak, and Bax) largely govern a cell's response to chemotherapy by mediating mitochondrial reaction to stressors that activate specific pro-death BH3 proteins. Many tumor types depend on altered BH protein interactions for survival. Our preliminary data shows that NB heterogeneously expresses Mcl1 and Bcl2 that may prevent apoptosis by sequestering active BH3 death signals. Further, BH3 mimetic peptides mimicking the death domain of BHS-only proteins potently induce NB apoptosis both in vitro and in vivo. Novel chemical modifications to stabilize peptide secondary structure improve serum stability and potency. We propose to exploit the knowledge of deregulated apoptotic pathways in NB to design rational pro-death therapeutic strategies with the following Aims: 1) Determine BH protein:protein interactions responsible for aberrant mitochondrial apoptosis in NB; 2) Assess the efficacy and potency of chemically modified BH3-domain peptides against NB cell lines both in vitro and in vivo; and 3) Demonstrate improved potency of BH3 peptides in these models when combined with tyrosine kinase inhibitors targeting receptors that mediate survival, proliferation and chemoresponse in neuroblastoma. This proposal lays out a 5-year research and training program that will help the principle investigator transition to become an independent researcher with the ultimate goal of becoming an R01-funded physician-scientist. Her mentors and advisors are leaders in the field of apoptosis, neuroblastoma, and experimental therapeutics. She will take advantage of the ample resources offered through the environments of both the Children's Hospital of Philadelphia and the University of Pennsylvania to foster her career development. Relevance. Neuroblastoma is a highly lethal tumor with no curative therapy following relapse. Current treatments are ineffective and new treatment depends on the identification of therapies that target tumor-specific biology. BH3 peptides that potently kill NB and other cancer cells prove promising as translational pro-death therapeutics given recent novel chemical modifications to improve peptide structure. Combining BH3 peptides with clinically available kinase inhibitors demonstrates that targeting both survival signaling and apoptosis using rationally chosen agents will provide a novel and effective approach to treating cancers resistant to current conventional treatment modalities.