Engineering tyrosine kinase-activated caspases for selective cancer cell killing

改造酪氨酸激酶激活的半胱天冬酶以选择性杀死癌细胞

基本信息

批准号：
8118973
负责人：
Sally A Kornbluth
金额：
$ 24.69万
依托单位：
DUKE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-08-01 至 2014-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8118973
关键词：
Acute Myelocytic Leukemia Animal Model Apoptosis Apoptotic Biological Caspase Cell Death Cells Cessation of life Chronic Chronic Myeloid Leukemia Cysteine Protease Cytochrome c1 Cytoplasm Engineering Enzymes FLT3 gene Family Future Goals Leukemic Cell Ligands Literature Mitochondria Molecular Normal Cell Oncogenic PDGFRA gene Patients Plague Protein Tyrosine Kinase Radiation Recruitment Activity Reporting Resistance Respiratory Chain Signal Pathway Stimulus Structure TNF gene Testing Validation apoptotic protease-activating factor 1 cancer cell caspase-8 caspase-9 cell killing chemotherapeutic agent chemotherapy clinical application cytochrome c drug discovery extracellular in vivo inhibitor/antagonist innovation kinase inhibitor leukemia mitochondrion intermembrane space novel novel strategies prevent public health relevance receptor binding response

项目摘要

DESCRIPTION (provided by applicant): The efficacy of most chemotherapeutic agents relies upon the efficient induction of apoptotic cell death. In the case of leukemias expressing activated tyrosine kinases (e.g., chronic myelogenous leukemias expressing Bcr-Abl, chronic myelomoncytic leukemias expressing Tel-PDGFR2, and acute myeloid leukemias expressing activated FLT3), the utility of conventional chemotherapeutics is limited by the fact that activated tyrosine kinases are potent inhibitors of apoptotic cell death. In addition, current targeted kinase inhibitors are plagued by problems of acquired resistance and, even when efficacious, they don't entirely eliminate the reservoir of leukemic cells and thus patients must remain on therapy indefinitely. It would be highly advantageous to develop treatments that could selectively and forcibly induce the death of leukemic cells expressing activated tyrosine kinases, while sparing normal cells. Many cellular signaling pathways impinge upon the cellular decision to die by apoptosis. However, under a variety of different circumstances, execution of the cell death program is carried out by a family of cysteine proteases known as caspases. Although caspases (such as caspase 8) can be activated in a fairly direct manner by receptor binding of extracellular "death ligands" such as Fas and TNF, caspase activation in response to damaging agents (radiation, chemotherapeutics) typically proceeds through the cell's mitochondria. By a mechanism that is still not entirely clear, apoptotic stimuli induce transit of the respiratory chain enzyme cytochrome c from the intermembrane space of the mitochondria to the cytoplasm. Engagement of a cytosolic protein, Apaf-1, by cytochrome c then nucleates the formation of a structure known as the apoptosome, in which caspase 9 is recruited to and activated by Apaf1/cytochrome c. In previous reports, Bcr-Abl has been shown to inhibit mitochondrial cytochrome c release, a function that renders cells remarkably resistant to chemotherapy-induced cell death. We have recently shown that Tel-PDGFR2 and FLT3/D835Y are similarly resistant. Moreover, even in the presence of cytosolic cytochrome c, these activated tyrosine kinases prevent activation of the apoptosome. We hypothesize that novel strategies are required to induce selective death of leukemic cells as the anti-apoptotic activity of these activated tyrosine kinases are likely to limit the utility of most chemotherapeutic agents. Towards this end, we have formulated an innovative strategy to promote selective caspase activation by a unique means in cells expressing activated tyrosine kinases. PUBLIC HEALTH RELEVANCE: We propose to engineer and test novel activators of cell death-promoting enzymes (caspases) that are activated by oncogenic tyrosine kinases with the goal of eliminating leukemic cells.

描述（由申请人提供）：大多数化学治疗剂的功效取决于有效诱导凋亡细胞死亡。在表达活化酪氨酸激酶的白血病中（例如表达BCR-ABL的慢性粒细胞性白血病，表达tel-PDGFR2的慢性脊髓念珠菌白血病和急性髓样白血病和表达活性FLT3的急性髓样白血病），受到传统化学疗法的限制性的tyrosication the kin kin kin kinthe kin kin kin kin kin the kin kin kin kin kin kin kin kin kin kin kin kin kin kin kin 死亡。此外，当前的靶向激酶抑制剂会受到获得性耐药性问题的困扰，即使有效，它们也不会完全消除白血病细胞的储层，因此患者必须无限期地进行治疗。开发可以选择性和强行诱导表达活化酪氨酸激酶的白血病细胞死亡的治疗方法是非常有利的，同时保留正常细胞。许多细胞信号通路会影响细胞凋亡死亡的细胞决定。但是，在各种不同的情况下，细胞死亡程序的执行是由一个称为caspase的半胱氨酸蛋白酶家族进行的。尽管caspase（例如caspase 8）可以通过相当直接的方式激活细胞外“死亡配体”（例如FAS和TNF），但通常会通过细胞细胞的线粒体来响应损害剂（辐射，化学治疗剂）而激活caspase激活。通过仍然尚不完全清楚的机制，凋亡刺激诱导呼吸链酶细胞色素C从线粒体的膜间空间到细胞质。然后，细胞色素c的胞质蛋白APAF-1参与成核形成了称为圆顶体的结构，其中caspase 9被APAF1/细胞色素c募集并激活。在先前的报告中，BCR-ABL已显示可抑制线粒体细胞色素C的释放，该功能使细胞对化学疗法诱导的细胞死亡具有明显抗性。我们最近表明，Tel-PDGFR2和FLT3/D835Y同样具有抗性。此外，即使在存在胞质细胞色素C的情况下，这些活化的酪氨酸激酶也会阻止凋亡组激活。我们假设需要新的策略来诱导白血病细胞的选择性死亡，因为这些活化的酪氨酸激酶的抗凋亡活性可能会限制大多数化学治疗剂的效用。为此，我们制定了一种创新的策略，以通过表达活性酪氨酸激酶的细胞中的独特手段促进选择性caspase激活。公共卫生相关性：我们建议设计和测试由致癌酪氨酸激酶激活的细胞死亡促进酶（caspase）的新型活化剂，目的是消除白血病细胞。