Role of Phapl in apoptosome regulation in ovarian cancer

Phapl 在卵巢癌凋亡体调节中的作用

• 批准号: 7108558
• 负责人: J REBECCA LIU
• 金额: $ 13.85万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-30 至 2009-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7108558
• 关键词: RNA interference; SDS polyacrylamide gel electrophoresis; apoptosis; autoradiography; biomarker; carcinoma; cell growth regulation; clinical research; cysteine endopeptidases; drug resistance; enzyme activity; enzyme induction /repression; human subject; immunocytochemistry; immunoprecipitation; molecular oncology; neoplastic growth; ovary neoplasms; posttranslational modifications; protein binding; protein structure function; tumor suppressor proteins; western blottings; women' s health

DESCRIPTION (provided by applicant): The long-term objective of this research is to define the molecular mechanism of dysfunctional apoptosome activation in epithelial ovarian carcinoma. This may lead to the identification of novel molecular targets for the treatment of ovarian cancer. This project is intended to contribute toward the long-term goal by testing the hypothesis that PHAPI, a tumor suppressor, plays a critical role in the regulation of apoptosome activation in ovarian cancer. The career development plan of this proposal is directed at promoting scientific independence of the candidate through interactions with established investigators in related fields. Alterations in the regulation of apoptosis may contribute to the pathogenesis of cancer and resistance of tumor cells to chemotherapy. In mammalian cells, non-receptor mediated apoptosis occurs predominantly via assembly of a cytochrome c dependent apoptosome complex containing caspase-9 and Apaf-1. We have shown that cytosolic extracts from human ovarian carcinoma cell lines and primary ovarian tumor samples are deficient in their ability to assemble and activate the apoptosome complex. Cell lines and tumor samples demonstrating dysfunctional apoptosome activation are associated with resistance to chemotherapy induced apoptosis. The molecular basis for apoptosome dysfunction in ovarian carcinoma appears to be due to an inability to recruit or retain caspase-9 in the apoptosome, and is associated with diminished Apaf-1/caspase-9 binding. PHAPI has been recently described as a facilitator of apoptosome-mediated caspase-9 activation. In an in vitro system, recombinant PHAPI stimulated caspase-3 activation, and induced increased amounts of caspase-9 to associate with the Apaf-1 oligomer. The regulatory role of PHAPI in apoptosis, and the clinical significance of this has not been clearly established. The Specific Aims of this project are to: 1) Correlate expression pattern of PHAPI with apoptosome function in a panel of ovarian carcinoma cell lines and primary ovarian tumor samples. 2) Determine if expression of PHAPI in chemoresistant ovarian carcinoma cell lines can restore apoptosome function. 3) Determine if PHAPI expression is required for apoptosome function in ovarian carcinoma.

描述（由申请人提供）：本研究的长期目标是确定上皮性卵巢癌中功能失调的凋亡体激活的分子机制。这可能会导致确定治疗卵巢癌的新分子靶点。该项目旨在通过检验肿瘤抑制因子 PHAPI 在卵巢癌凋亡体激活调节中发挥关键作用的假设，为实现长期目标做出贡献。该提案的职业发展计划旨在通过与相关领域的知名研究人员的互动来促进候选人的科学独立性。 细胞凋亡调节的改变可能有助于癌症的发病机制和肿瘤细胞对化疗的耐药性。在哺乳动物细胞中，非受体介导的细胞凋亡主要通过含有 caspase-9 和 Apaf-1 的细胞色素 c 依赖性凋亡体复合物的组装发生。我们已经证明，人卵巢癌细胞系和原发性卵巢肿瘤样品的胞质提取物缺乏组装和激活凋亡体复合物的能力。表现出功能失调的凋亡体激活的细胞系和肿瘤样本与对化疗诱导的细胞凋亡的抵抗相关。卵巢癌凋亡体功能障碍的分子基础似乎是由于凋亡体中无法募集或保留 caspase-9，并且与 Apaf-1/caspase-9 结合减少有关。 PHAPI 最近被描述为凋亡体介导的 caspase-9 激活的促进剂。在体外系统中，重组 PHAPI 刺激 caspase-3 激活，并诱导 caspase-9 数量增加，与 Apaf-1 寡聚物结合。 PHAPI 在细胞凋亡中的调节作用及其临床意义尚未明确。 该项目的具体目标是： 1) 将 PHAPI 的表达模式与一组卵巢癌细胞系和原发性卵巢肿瘤样本中的凋亡体功能相关联。 2)确定化疗耐药卵巢癌细胞系中PHAPI的表达是否可以恢复凋亡体功能。 3) 确定卵巢癌中凋亡体功能是否需要 PHAPI 表达。