Optimizing Pro-Apoptotic Therapeutics With Kinase Inhibition in Neuroblastoma

描述(申请人提供)：神经母细胞瘤(NB)是一种常见的儿童实体瘤，具有很高的致命性。大多数患者存在高危特征，并因肿瘤细胞凋亡途径障碍而死于化疗耐药疾病。BCL2同源结构域或BH蛋白(如BCL2、MCL1、Bak和Bax)主要通过介导线粒体对应激源的反应来激活特定的促死亡BH3蛋白，从而控制细胞对化疗的反应。许多肿瘤类型依赖于改变的BH蛋白相互作用来生存。我们的初步数据显示，NB异质性地表达MCL1和BCL2，这可能通过隔离活跃的BH3死亡信号来阻止细胞凋亡。此外，模拟BHS-Only蛋白死亡结构域的BH3模拟肽在体外和体内都能有效地诱导NB细胞凋亡。稳定多肽二级结构的新化学修饰提高了血清的稳定性和效价。我们建议利用对NB细胞凋亡途径的了解来设计合理的促死亡治疗策略，目标如下：1)确定BH蛋白：导致NB中线粒体异常凋亡的蛋白质相互作用；2)评估化学修饰的BH3-结构域多肽在体外和体内对NB细胞系的效力和效力；以及3)证明BH3多肽在这些模型中的效力得到提高，当与针对介导神经母细胞瘤存活、增殖和化学反应的受体的酪氨酸激酶抑制剂相结合时。 这项提案列出了一个为期5年的研究和培训计划，将帮助首席研究员转变为独立研究员，最终目标是成为一名R01资助的内科科学家。她的导师和顾问是细胞凋亡、神经母细胞瘤和实验治疗学领域的领导者。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。 关联性。神经母细胞瘤是一种高度致命的肿瘤，复发后无法治愈。目前的治疗方法是无效的，新的治疗方法取决于针对肿瘤特异性生物学的治疗方法的确定。BH3多肽可以有效地杀死NB和其他癌细胞，由于最近为了改善多肽结构而进行的新的化学修饰，因此被证明是有希望的翻译亲死亡治疗药物。BH3多肽与临床上可用的激酶抑制剂相结合表明，通过合理选择靶向生存信号和细胞凋亡的药物，将为治疗对当前常规治疗方式耐药的癌症提供一种新的有效途径。

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.