Tyrosine Kinases and Thrombosis

项目摘要 酪氨酸激酶抑制剂(TKIs)是治疗多种癌症的重要药物。但是，任何 毒剂在疗效和靶上或靶外的有害影响之间进行权衡。这个概念在以下方面变得明显 强效广谱抑制性酪氨酸激酶治疗慢性粒细胞白血病 抑制剂，波纳替尼(Iclusig，Ariad PharmPharmticals，现在的武田)被认为有31%的发病率 心血管事件(CV)，其中21%为严重不良事件(SAE)。在第二阶段试验中 (佩斯)4岁。动脉闭塞事件的发生率为26%(心肌梗死14%，卒中11%， 和肢体缺血11%-一些患者有一个以上的器官事件)。Ponatinib(Poni)是5个TKI之一 批准用于治疗慢性粒细胞白血病 我们已经建立了一个小鼠模型来检测TKIs对凝血、血管和血小板的影响 功能。在稳态条件下接受各种TKI治疗的老年小鼠中，与伊马替尼不同的是， 显示动脉和静脉血栓形成的风险增加。PONI治疗导致动脉减少 闭塞时间、较大的静脉凝块和产生过度活跃的血小板--这些特征有助于 血栓形成加重。我们的实验室已经确定了血栓前病变的关键机制 马尾松的表型。首先，用PINI治疗的小鼠血管壁活性氧(ROS)增加， 细胞凋亡和炎性血管淋巴细胞浸润，表达凝血因子V和VIII。 其次，用青春痘治疗的小鼠的血小板对胶原蛋白反应过度。此外，我们还有 PPAR激动剂吡格列酮(Pio)与PIPI一起给药可使血管壁正常化 炎症和血小板亢进纠正小鼠血栓形成风险 这一应用的总体假设是脑桥相关血栓形成是免疫细胞血管的结果。 炎症表达血栓前基因，改变血小板信号，导致血小板高反应性。 PONI治疗发现了一种新的血栓前血管功能障碍的机制，通过这种机制，血管 浸润性淋巴细胞表达凝血酶Fv和FVIII，可能与血栓形成有关。在… 人的治疗性剂量，PINI抑制激活的GPVI的负调节因子p-LynY507，在未刺激的情况下 而活化的血小板对p-LynY396和p-SykY352几乎没有影响，这表明这些血小板可能是 更多的反应。事实上，用PINI治疗的小鼠有对较低浓度的CRP产生反应的血小板。这些 Pio的基因组和非基因组的PPAR激动剂可以从基因和功能上纠正缺陷。这个 该建议的具体目标如下： 该提案的具体目的如下：1)确定波纳替尼和其他TKI的机制- 诱导血管炎症2)明确PINI诱导的血小板过度激活的机制。 这些研究将确定PINI和其他TKI对血管壁和血小板的作用机制 会导致心血管事件。他们提出了青春痘相关血栓形成和矫正的临床前模型。 使用PPAR激动剂Pio。最后，它们将作为对TKI进行心血管疾病评估的范例。

Project Summary Tyrosine kinase inhibitors (TKIs) are important therapeutic agents to treat various cancers. However, any agent has a tradeoff between efficacy and on or off target deleterious effects. This notion became evident in the treatment of chronic myelogenous leukemia (CML) when a potent and broadly inhibitory tyrosine kinase inhibitor, ponatinib (Iclusig, Ariad Pharmaceuticals, now Takeda) was recognized to have a 31% incidence of cardiovascular (CV) events of which 21% overall were significant adverse events (SAEs). In a Phase II trial (PACE) at 4 yrs. the incidence of arterial occlusive events was 26% (myocardial infarction 14%, stroke 11%, and limb ischemia 11% - some patients have more than 1 organ event). Ponatinib (poni) is one of 5 TKIs approved for the treatment of CML We have created a murine model to examine the effects of TKIs on blood coagulation, vascular, and platelet function. In aged mice treated with the various TKIs under steady-state conditions, ponatinib, unlike imatinib, demonstrated an increased risk of arterial and venous thrombosis. Poni treatment leads to decreased arterial occlusion times, larger venous clots and generates hyperactive platelets - features that contribute to heightened thrombosis. Our laboratory has identified key mechanisms underlying the prothrombotic phenotype of poni. First, poni-treated mice have increased vessel wall reactive oxygen species (ROS), apoptosis, and inflammatory vascular lymphocyte infiltrates that expresses coagulation factors V and VIII. Second, platelets from poni-treated mice are hyperactive to in response to collagen. Additionally, we have determined that pioglitazone (pio), a PPAR agonist, when given with poni normalizes the vessel wall inflammation and platelet hyperactivity to correct murine thrombosis risk The overall hypothesis of this application is that poni-associated thrombosis results from immune cell vascular inflammation expressing prothrombotic genes and altered platelet signaling resulting in platelet hyperreactivity. Poni treatment has identified a novel mechanism of prothrombotic vascular dysfunction by which vascular infiltrating lymphocytes express coagulation enzymes FV and FVIII potentially to contribute to thrombosis. At therapeutic dosing in man, poni inhibits p-LynY507, a negative regulator of activated GPVI, in both unstimulated and activated platelets with little effect on p-LynY396 and p-SykY352, suggesting that these platelets may be more reactive. In fact, poni-treated mice have platelets that react to lower concentrations of CRP. These defects are genetically and functionally corrected by pio’s genomic and non-genomic PPAR agonism. The specific aims of the proposal are as follows: The specific aims of the proposal are as follows: 1) Determine the mechanism of ponatinib- and other TKI- induced vascular inflammation 2) Identify the mechanisms of poni-induced platelet hyperactivation. These studies will determine the mechanisms of poni and other TKI effects on vessel wall and platelets that lead to cardiovascular events. They present a pre-clinical model for poni-associated thrombosis and correction with pio, a PPAR agonist. Last, they will serve as a paradigm for CVD assessment for TKIs in general.