Molecular mechanisms of chemoresistance in breast cancer

乳腺癌化疗耐药的分子机制

• 批准号: 7892805
• 负责人: Manabu Kurokawa
• 金额: $ 9.55万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7892805
• 关键词: Academic Medical Centers; Advisory Committees; Apoptosis; Apoptotic; Area; Award; Biochemical; Biological; Breast; Breast Cancer Cell; Cancer Patient; Caspase; Cell Cycle; Cell Cycle Progression; Cell Death; Cell Death Induction; Cell Death Signaling Process; Cell Line; Cells; Cessation of life; Clinical; Complex; Cysteine Protease; Cytoplasm; Defect; Development; Developmental Biology; Dissection; Down-Regulation; ERBB2 gene; Ensure; Environment; Exhibits; FDA approved; Funding; Goals; Heat-Shock Proteins 90; Homeostasis; Immersion Investigative Technique; K-Series Research Career Programs; Laboratories; MDM2 gene; Malignant Neoplasms; Mediating; Mentors; Mitochondria; Modeling; Molecular; Molecular Analysis; Molecular and Cellular Biology; Mus; Normal tissue morphology; Pathway interactions; Phosphorylation; Play; Positioning Attribute; Predisposition; Proteins; Receptor Protein-Tyrosine Kinases; Regulation; Research; Research Personnel; Resistance; Resistance development; Role; Senior Scientist; Signal Pathway; Signal Transduction; Stimulus; Structure; Testing; Time; Training; Universities; Up-Regulation; Work; Xenograft Model; aposome; base; cancer cell; career; career development; chemotherapeutic agent; cytochrome c; cytotoxic; inhibitor/antagonist; innovation; insight; knowledge base; lapatinib; malignant breast neoplasm; novel; novel therapeutics; outcome forecast; overexpression; protein degradation; public health relevance; response; skills; stressor; tool; tumor; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): Apoptosis is a form of programmed cell death that plays a crucial role in normal tissue homeostasis and development. In response to various genotoxic or cytotoxic stressors, apoptosis occurs by release of cytochrome c from the mitochondria, which promotes nucleation of a structure known as the apoptosome to activate cysteine proteases called caspases. In contrast to untransformed cells, cancer cells exhibit marked resistance to apoptosis by blocking mitochondrial cytochrome c release and/or by inhibiting apoptosome formation following cytochrome c release. Overexpression of the receptor tyrosine kinase ErbB2 is known to be associated with poor prognosis in breast cancer patients. Despite the availability of ErbB2-specific molecular inhibitors, the majority of ErbB2- overexpressing breast cancers eventually develop resistance to these inhibitors over a period of time (i.e., acquired resistance), suggesting the presence of currently uncharacterized mechanisms of chemoresistance. In this proposal, I investigate the molecular mechanisms contributing to apoptotic inhibition in breast cancers with acquired resistance to lapatinib, an FDA-approved ErbB2 inhibitor. It is my central hypothesis that inhibition of apoptosome formation plays a critical role in acquired lapatinib resistance in breast cancer. This hypothesis was formulated based on evidence from our laboratory as well as from others demonstrating that apoptosome inhibition can occur by two key independent pathways: HSP902 hypophosphorylation and CAS downregulation. Apoptosome inhibition by these mechanisms may override cell death signals caused by various pro-apoptotic stimuli. Towards this end, I will pursue the following two specific aims: 1) to determine the role of HSP902 hypophosphorylation in acquired lapatinib resistance, and 2) to elucidate the molecular mechanism of CAS downregulation. My primary career goal is to obtain a tenure-track position in an academic setting at a major U.S. university. My long-term goal is to build an independent research career as a molecular cancer biologist. To achieve these goals, I hope to both develop my intellectual knowledge base as well as increase my technical skill repertoire throughout the duration of the proposed study. This training should be readily attainable in the Kornbluth laboratory at Duke University Medical Center; our lab has considerable expertise in the biochemical analysis and molecular dissection of complex signaling pathways, both during apoptosis and cell cycle progression. In addition, I have obtained two outstanding collaborators, Drs. Neil Spector and Mark Dewhirst, who are established investigators in the fields of breast cancer and mouse xenograft models of cancer, respectively. Moreover, in order to promote and assure my progress during the Career Development Award period, I have organized an advisory committee consisting of well-established senior scientists with expertise in different areas relevant to my research and career goals. Collectively, the proposed studies will provide significant insight into mechanisms of chemoresistance and potential strategies for sensitizing cells to pro-apoptotic agents. Moreover, this work will provide me with the means to establish myself as an independent investigator. PUBLIC HEALTH RELEVANCE: Cancer cells are markedly resistant to apoptotic cell death. In this proposal, we focus on mechanisms of cell death dysregulation in breast cancers, particularly under conditions of acquired resistance to chemotherapeutic agents. This study should help to elucidate mechanisms of breast chemoresistance and aid in the development of novel therapeutic strategies to avoid such resistance.

描述（由申请人提供）：细胞凋亡是一种程序性细胞死亡形式，在正常组织稳态和发育中起关键作用。响应于各种遗传毒性或细胞毒性应激物，细胞凋亡通过从线粒体释放细胞色素c而发生，细胞色素c促进称为线粒体的结构成核以激活称为半胱氨酸天冬氨酸蛋白酶的半胱氨酸蛋白酶。与未转化的细胞相反，癌细胞通过阻断线粒体细胞色素c释放和/或通过抑制细胞色素c释放后的线粒体形成而表现出对凋亡的显著抗性。 已知受体酪氨酸激酶ErbB 2的过表达与乳腺癌患者的不良预后相关。尽管存在ErbB 2特异性分子抑制剂，但大多数ErbB 2过表达乳腺癌最终在一段时间内对这些抑制剂产生耐药性（即，获得性抗性），表明存在目前未表征的化学抗性机制。在这个建议中，我调查的分子机制，有助于乳腺癌细胞凋亡抑制与获得性耐药性拉帕替尼，FDA批准的ErbB 2抑制剂。这是我的中心假设，抑制乳腺癌中的拉帕替尼获得性耐药中起着至关重要的作用。这一假设是基于我们实验室以及其他实验室的证据制定的，这些证据表明，溶酶体抑制可以通过两个关键的独立途径发生：HSP 902磷酸化不足和CAS下调。通过这些机制的凋亡体抑制可以覆盖由各种促凋亡刺激引起的细胞死亡信号。为此，我将追求以下两个具体目标：1）确定HSP 902低磷酸化在获得性拉帕替尼耐药中的作用，2）阐明CAS下调的分子机制。我的主要职业目标是在美国主要大学的学术环境中获得终身职位。我的长期目标是建立一个独立的研究生涯作为一个分子癌症生物学家。为了实现这些目标，我希望在整个拟议的研究期间，既发展我的知识基础，又增加我的技术技能。这种培训应该很容易在杜克大学医学中心的Kornbluth实验室实现;我们的实验室在细胞凋亡和细胞周期进程中复杂信号通路的生化分析和分子解剖方面具有相当的专业知识。此外，我还获得了两位杰出的合作者，Neil Spector博士和Mark Dewhirst博士，他们分别是乳腺癌和小鼠异种移植癌症模型领域的研究人员。此外，为了促进和确保我在职业发展奖期间的进步，我组织了一个咨询委员会，由在与我的研究和职业目标相关的不同领域具有专业知识的资深科学家组成。总的来说，拟议的研究将提供显着的洞察机制的化疗耐药性和潜在的战略敏感细胞促凋亡剂。此外，这项工作将为我提供建立自己作为一个独立调查员的手段。 公共卫生相关性：癌细胞对凋亡性细胞死亡具有显著抵抗力。在这个建议中，我们专注于乳腺癌细胞死亡失调的机制，特别是在获得性耐药化疗药物的条件下。这项研究将有助于阐明乳腺癌耐药的机制，并有助于开发新的治疗策略以避免这种耐药。