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：
8490683
负责人：
Sally A Kornbluth
金额：
$ 23.19万
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/8490683
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.

描述（由申请人提供）：大多数化疗药物的功效依赖于有效诱导细胞凋亡。对于表达活化酪氨酸激酶的白血病（例如，表达 Bcr-Abl 的慢性粒细胞白血病、表达 Tel-PDGFR2 的慢性粒细胞白血病和表达活化 FLT3 的急性粒细胞白血病），传统化疗药物的效用受到以下事实的限制：活化酪氨酸激酶激酶是细胞凋亡的有效抑制剂。此外，目前的靶向激酶抑制剂受到获得性耐药问题的困扰，即使有效，它们也不能完全消除白血病细胞库，因此患者必须无限期地继续治疗。开发能够选择性地、强制地诱导表达活化酪氨酸激酶的白血病细胞死亡，同时不伤害正常细胞的治疗方法将是非常有利的。许多细胞信号传导途径影响细胞通过细胞凋亡而死亡的决定。然而，在各种不同的情况下，细胞死亡程序的执行是由称为半胱天冬酶的半胱氨酸蛋白酶家族执行的。尽管半胱天冬酶（如半胱天冬酶 8）可以通过细胞外“死亡配体”（如 Fas 和 TNF）的受体结合以相当直接的方式激活，但响应损伤剂（放射、化疗）的半胱天冬酶激活通常通过细胞的线粒体进行。通过一种尚不完全清楚的机制，凋亡刺激诱导呼吸链酶细胞色素c从线粒体的膜间隙转运至细胞质。细胞色素 c 与胞质蛋白 Apaf-1 结合，然后形成称为凋亡体的结构，其中 caspase 9 被 Apaf1/细胞色素 c 募集并激活。在之前的报告中，Bcr-Abl 已被证明可以抑制线粒体细胞色素 c 的释放，这种功能使细胞对化疗引起的细胞死亡具有显着的抵抗力。我们最近表明 Tel-PDGFR2 和 FLT3/D835Y 具有类似的耐药性。此外，即使存在胞质细胞色素 c，这些激活的酪氨酸激酶也会阻止凋亡体的激活。我们假设需要新的策略来诱导白血病细胞的选择性死亡，因为这些激活的酪氨酸激酶的抗凋亡活性可能会限制大多数化疗药物的效用。为此，我们制定了一种创新策略，通过独特的方式在表达活化酪氨酸激酶的细胞中促进选择性 caspase 活化。