Proteasome Inhibition and ER Stress

蛋白酶体抑制和内质网应激

• 批准号: 8008803
• 负责人: David J. McConkey
• 金额: $ 24.8万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-01 至 2013-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8008803
• 关键词: Ablation; Acetylation; Address; Affect; Animals; Apoptosis; Attenuated; Biochemical; Biological; Biological Assay; Biopsy; Bortezomib; Cancer cell line; Cell Death; Cell Line; Cells; Cellular Stress; Chemicals; Chromatin; Clinical Trials; Collaborations; Combination Drug Therapy; Combined Modality Therapy; Data; Defect; Development; Dominant-Negative Mutation; Drug Delivery Systems; Drug resistance; Drug-sensitive; Enrollment; Epithelial Cells; Exposure to; FDA approved; Gene Expression; Gene Silencing; Genes; Goals; Golgi Apparatus; Growth; HDAC6 gene; Health; Heat-Shock Proteins 70; Heterogeneity; Histone Deacetylase; Histone Deacetylase Inhibitor; Histone deacetylase inhibition; Histones; Human; Immunohistochemistry; In Vitro; Inflammation; Laboratories; Ligands; Link; MAPK8 gene; Malignant Neoplasms; Malignant neoplasm of pancreas; Measures; Mediating; Medicine; Methods; Molecular; Molecular Profiling; Mus; Noxae; Nuclear; Nutrient; Pancreas; Pathway interactions; Patients; Pattern; Peripheral Blood Mononuclear Cell; Pharmaceutical Preparations; Pharmacodynamics; Phase II Clinical Trials; Phenotype; Phosphorylation; Physiological; Play; Pre-Clinical Model; Process; Production; Proteasome Inhibition; Proteasome Inhibitor; Protein Biosynthesis; Protein Kinase; Proteins; Publishing; Regimen; Relative (related person); Research; Resistance; Role; Serum; Small Interfering RNA; Solid; Stress; Structure; TNFSF10 gene; Techniques; Testing; Therapeutic Intervention; Toxic effect; Translations; Transmission Electron Microscopy; Tubulin; Tumor Necrosis Factor-alpha; Tumor-Derived; Vorinostat; Work; Xenograft procedure; angiogenesis; arm; base; cancer cell; cancer therapy; carcinogenesis; cell killing; chronic pancreatitis; clinical application; cytotoxic; epithelial to mesenchymal transition; gemcitabine; human CASP4 protein; inhibitor/antagonist; interest; killings; mRNA Expression; multicatalytic endopeptidase complex; neoplastic cell; novel; pancreatic cancer cells; peripheral blood; pre-clinical; prevent; prospective; protein expression; protein misfolding; research study; response; synthetic protein; therapy resistant; transcription factor; tubacin; tumor; tumor progression; tumor xenograft

DESCRIPTION (provided by applicant): Proteasome inhibitor (PI)-based combination chemotherapy is currently being evaluated for the treatment of pancreatic cancer and other solid malignancies. Our hypothesis is that PIs cause endoplasmic reticular (ER) stress in cancer cells and this stress mediates cell killing. Furthermore, we have obtained preliminary evidence that the effects of PIs on cell death are highly heterogeneous and are linked to whether or not they induce phosphorylation of eIF21, a component of the unfolded protein response (UPR) that mediates suppression of global protein synthesis. Specifically, PIs promote strong phosphorylation of eIF21 phosphorylation in the cell lines that are relatively resistant to PI-induced apoptosis, but they fail to do so (or attenuate translation) in the cell lines that are most sensitive. Identifying the biochemical basis for this heterogeneity could enable the prospective identification of tumors that are most likely to respond to PI-based combination chemotherapy and should yield new targets for therapeutic intervention. We also wish to better define the molecular mechanisms involved in the apoptosis that is induced by one of the most promising PI-based combination regimens, namely, the combination of bortezomib plus histone deacetylase (HDAC) inhibitors. We have obtained good preliminary evidence that HDAC inhibitors promote proteasome inhibitor-mediated apoptosis by disrupting cytoprotective structures known as aggresomes that appear to function to alleviate ER stress. Gene silencing studies have demonstrated that the HDAC responsible for aggresome disruption is HDAC6, and it is possible that more selective HDAC6 inhibitors will yield comparable or better tumor cell killing than pan HDAC inhibitors (like SAHA) with less toxicity. To directly test our hypotheses we propose the following Specific Aims. (1) Define the molecular mechanisms that control bortezomib-induced phosphorylation of eIF21. We will test the hypothesis that PIs inhibit PERK activation by inducing the expression of a molecular chaparone (HSP70?) that blocks PERK homoaggregation in drug-sensitive cells; (2) Determine role of ER stress in PI-induced apoptosis. Here we will assess the contributions of ROS, Ca2+, JNK, Noxa, and caspase-4 ot PI-induced apoptosis; (3): Determine the toxicity and anti-tumor efficacy of combination therapy with PIs and HDAC inhibitors in xenografts. We will compare the effects of combination therapy with PIs plus SAHA (a pan HDAC inhibitor), tubacin (HDAC6-selective), or SNDX-275 (type I HDAC-specific) in vitro and in orthotopic tumors derived from sensitive and resistant cell lines. We will also investigate whether or not pharmacodynamic markers of drug-target interaction and biological response can be measured in the peripheral blood of these animals and apply these methods to measure the effects of therapy with bortezomib plus SAHA within the context of a Phase II clinical trial in patients with pancreatic cancer. PUBLIC HEALTH RELEVANCE: Clinical trials have demonstrated that the effects of conventional and investigational cancer therapies are remarkably heterogeneous, and efforts are currently underway to match therapies to the specific molecular features associated with responsiveness to them in an effort to better exploit their effects ("personalized medicine"). The overall goal of the research proposed here is to better understand the mechanisms involved in cell killing induced by two promising classes of investigational cancer therapies (proteasome inhibitors and histone deacetylase inhibitors) so that the promising effects of these drugs that have been noted in preclinical models can be best exploited in patients. We will be directly comparing the effects of two proteasome inhibitors and three HDAC inhibitors that are either already FDA-approved, being evaluated in clinical trials, or being developed for clinical application in humans, and in our third Specific Aim we will develop and apply pharmacodynamic assays to measure drug-target interactions and the biological consequences of effective drug targeting within the context of a Phase II clinical trial in patients.

描述（由申请人提供）：目前正在评估基于蛋白酶体抑制剂（PI）的联合化疗对胰腺癌和其他实体恶性肿瘤的治疗作用。我们的假设是，PI 会导致癌细胞内质网状 (ER) 应激，而这种应激会介导细胞死亡。此外，我们还获得了初步证据，表明 PI 对细胞死亡的影响具有高度异质性，并且与它们是否诱导 eIF21 磷酸化有关，eIF21 是未折叠蛋白反应 (UPR) 的一个组成部分，介导整体蛋白质合成的抑制。具体而言，PI 在对 PI 诱导的细胞凋亡相对抵抗的细胞系中促进 eIF21 磷酸化的强烈磷酸化，但在最敏感的细胞系中却无法做到这一点（或减弱翻译）。确定这种异质性的生化基础可以前瞻性地识别最有可能对基于 PI 的联合化疗产生反应的肿瘤，并应产生治疗干预的新目标。我们还希望更好地定义最有前途的基于 PI 的组合方案之一（即硼替佐米加组蛋白脱乙酰酶 (HDAC) 抑制剂的组合）诱导细胞凋亡的分子机制。我们已经获得了良好的初步证据，表明 HDAC 抑制剂通过破坏称为聚集体的细胞保护结构来促进蛋白酶体抑制剂介导的细胞凋亡，而聚集体似乎具有减轻 ER 应激的功能。基因沉默研究表明，负责破坏聚集体的 HDAC 是 HDAC6，并且选择性更强的 HDAC6 抑制剂可能会产生与全 HDAC 抑制剂（如 SAHA）相当或更好的肿瘤细胞杀伤效果，且毒性较小。为了直接检验我们的假设，我们提出以下具体目标。 (1) 定义控制硼替佐米诱导的 eIF21 磷酸化的分子机制。我们将测试以下假设：PI 通过诱导分子伴侣 (HSP70?) 的表达来抑制 PERK 激活，该分子伴侣可阻止药物敏感细胞中的 PERK 同聚集； (2)确定ER应激在PI诱导的细胞凋亡中的作用。在这里，我们将评估 ROS、Ca2+、JNK、Noxa 和 caspase-4 对 PI 诱导的细胞凋亡的贡献； (3)：确定PIs和HDAC抑制剂联合治疗在异种移植物中的毒性和抗肿瘤功效。我们将比较 PI 加 SAHA（一种泛 HDAC 抑制剂）、tubacin（HDAC6 选择性）或 SNDX-275（I 型 HDAC 特异性）的联合治疗在体外以及在敏感和耐药细胞系衍生的原位肿瘤中的效果。我们还将研究是否可以在这些动物的外周血中测量药物-靶点相互作用和生物反应的药效学标志物，并在胰腺癌患者的 II 期临床试验中应用这些方法来测量硼替佐米加 SAHA 的治疗效果。 公共健康相关性：临床试验已经证明，传统癌症疗法和研究性癌症疗法的效果存在显着差异，目前正在努力将疗法与与其反应相关的特定分子特征相匹配，以更好地利用其效果（“个性化医疗”）。这里提出的研究的总体目标是更好地了解两类有前途的研究性癌症疗法（蛋白酶体抑制剂和组蛋白脱乙酰酶抑制剂）诱导的细胞杀伤机制，以便可以在患者身上最好地利用这些在临床前模型中注意到的药物的有希望的作用。我们将直接比较两种蛋白酶体抑制剂和三种 HDAC 抑制剂的效果，这些抑制剂要么已经获得 FDA 批准，正在临床试验中进行评估，要么正在开发用于人体临床应用，在我们的第三个具体目标中，我们将开发和应用药效学测定来测量药物与靶标的相互作用以及在患者 II 期临床试验的背景下有效药物靶向的生物学后果。