The Role of Ceramidases in Cancer Chemotherapy

神经酰胺酶在癌症化疗中的作用

基本信息

批准号：
8510601
负责人：
CUNGUI MAO
金额：
$ 30.72万
依托单位：
STATE UNIVERSITY NEW YORK STONY BROOK
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-07-13 至 2017-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8510601
关键词：
Animal Model Apoptosis Attenuated Breast Cancer Cell Cancer cell line Cell Cycle Arrest Cell Cycle Progression Cell membrane Cells Ceramidase Ceramides Chemotherapy-Oncologic Procedure Cisplatin Data Development Doxorubicin Drug resistance Endoplasmic Reticulum Enzymes Etoposide Future Generations Goals Golgi Apparatus Hela Cells Human Hydrolysis In Vitro Inhibition of Apoptosis Lipids MDA MB 231 Malignant Neoplasms Mammalian Cell Mediating Mediator of activation protein Mitotic Pathway interactions Pharmaceutical Preparations Phase Proteins Publishing Role Sphingolipids Sphingomyelinase Sphingosine TNF gene Testing Therapeutic United States base cancer cell cancer prevention cancer therapy chemotherapeutic agent chemotherapy cytokine cytotoxicity galactosylgalactosylglucosylceramidase gemcitabine insight killings knock-down neoplastic cell novel novel strategies response senescence

项目摘要

DESCRIPTION (provided by applicant): Our long-term goal is to define the mechanisms by which anti-cancer chemotherapeutic agents (ACCAs) induce anti-proliferative responses (proliferation inhibition and programmed cell death) in tumor cells by focusing on human alkaline ceramidase 2 (ACER2) and its lipid substrate (ceramide) and product (sphingosine). Many ACCAs induce the generation of the bioactive sphingolipid ceramide in tumor cells, and blocking ceramide generation inhibits anti-proliferative effects of the drugs, suggesting that ceramide is an important mediator of ACCAs in this anti-proliferative response. Ceramide can be hydrolyzed into sphingosine by ceramidases in human cells and, like ceramide, SPH can potently induce anti-proliferative effects in tumor cells both in vitro and in animal models. Increasing expression of neutral ceramidase ASAH2 on the plasma membrane also attenuates cell apoptosis induced by TNF-1, a known ceramide-generating cytokine. In contrast, our preliminary studies show that increasing the conversion of ceramide to SPH by the Golgi alkaline ceramidase 2 (ACER2) markedly enhances the cytotoxicity of doxorubicin, a known ceramide-inducing ACCA, in HeLa cells, whereas knocking down ACER2 has the opposite effect. This exciting finding led us to the hypotheses that ACCAs exert anti-proliferative responses in cancer cells through the ceramide/ACER2/SPH pathway and that activation of this pathway will augment chemotherapy action in cancer treatment. To test this hypothesis, we will establish that the ceramide/ACER2/SPH pathway is an important mediator of the anti- proliferative responses of ACCAs in cancer cells by determining 1) if ACCAs induce the anti-proliferative responses in cancer cells by activating the ceramide/ACER2/SPH pathway; 2) if ACER2-inducing agents enhance whereas ACER2-inhibiting agents attenuate the ACCA-induced anti-proliferative effects in cancer cells (Aim 1). In Aim 2, we will test the hypothesis that its Golgi localization is required for ACER2 to mediate the ACCA-induced anti-proliferative responses in cancer cells by investigating 1) if targeting ACER2 to the endoplasmic reticulum (ER) abolishes its ability to mediate the ACCA-induced anti-proliferative effects in tumor cells; and 2) if targeting ASAH2 to the Golgi complex confers the ability to mediate ACCA-induced anti- proliferative effects in tumor cells. For Aim 3, we will test the hypothesis that the activation of the ACER2/SPH pathway enhances anti-proliferative responses of ACCAs in tumor cells through Golgi fragmentation. We will determine 1) if ACCAs induces Golgi fragmentation by activating the ceramide/ACER2/SPH pathway; 2) if SPH induces Golgi fragmentation and inhibits Golgi reassembly in vitro; 3) if activating the ceramide/ACER2/SPH inhibits Golgi assembly by inhibiting the stacking function of GRASP65 (Golgi reassembly stacking protein of 65 kD) and GRASP55; and 4) if activation of the ceramide/ACER2/SPH pathway induces mitotic arrest and apoptosis through Golgi fragmentation. These studies will provide insights into the role and mechanism of action of ACER2 and its product SPH in mediating anti-proliferative responses in cancer cells.

描述（由申请人提供）：我们的长期目标是定义抗癌化学治疗剂（ACCAS）诱导抗增殖反应（增殖抑制和程序性细胞死亡）的机制。（ACER2）及其脂质底物（神经酰胺）和产物（鞘氨酸）。许多ACSA诱导肿瘤细胞中生物活性鞘脂神经酰胺的产生，并且阻断神经酰胺的产生抑制了药物的抗增殖作用，这表明神经酰胺是这种抗增殖反应中ACCAS的重要介体。神经酰胺可以通过人类细胞中的神经酶水解为鞘氨醇，例如神经酰胺，SPH可以在体外和动物模型中有效诱导肿瘤细胞中的抗增殖作用。中性神经酰胺酶ASAH2在质膜上的表达增加也减弱了TNF-1诱导的细胞凋亡，TNF-1是一种已知的神经酰胺生成的细胞因子。相比之下，我们的初步研究表明，高尔基碱神经酰胺酶2（ACER2）将神经酰胺转化为SPH，显着增强了阿霉素的细胞毒素，一种已知的神经酰胺诱导的ACCA，而在Hela中具有相反的ACER2，使ACER2撞倒ACER2。。这一令人兴奋的发现使我们提出了通过神经酰胺/ACER2/SPH途径在癌细胞中发挥抗增殖反应的假设，并且该途径的激活将增加癌症治疗中的化学疗法作用。为了检验这一假设，我们将确定神经酰胺/ACER2/SPH途径是癌细胞中ACCAS抗增殖反应的重要介体，通过确定1）如果ACCA通过激活ceramide诱导癌细胞中的抗增殖反应。 /acer2/sph途径； 2）如果诱导ACER2诱导剂增强，而ACER2抑制剂会减弱ACCA诱导的癌细胞抗增殖作用（AIM 1）。在AIM 2中，我们将检验以下假设：ACER2需要介导癌细胞中ACCA诱导的抗增殖反应需要的假说，通过研究ACER2将ACER2靶向于内质网（ER），可以消除其介导其介导其介导的能力。 ACCA诱导的抗增殖作用在肿瘤细胞中； 2）如果将ASAH2靶向高尔基体络合物，则赋予介导ACCA诱导的抗增殖作用的能力。对于AIM 3，我们将检验以下假设：ACER2/SPH途径的激活通过高尔基体碎片来增强肿瘤细胞中ACCAS的抗增殖反应。我们将确定1）ACCAS是否通过激活神经酰胺/ACER2/SPH途径诱导高尔基体碎片； 2）如果SPH诱导高尔基体碎裂并抑制高尔基体在体外重新组装； 3）如果激活神经酰胺/ACER2/SPH，通过抑制Grasp65（Golgi重新组装堆叠蛋白为65 kd）和Grasp55的堆叠功能来抑制高尔基体组装； 4）如果激活神经酰胺/ACER2/SPH途径会通过高尔基体碎片诱导有丝分裂停滞和凋亡。这些研究将提供有关ACER2及其产物SPH在介导癌细胞中抗增殖反应中的作用的作用和机理的见解。