Proteasome Inhibition and ER Stress

蛋白酶体抑制和内质网应激

• 批准号: 8204790
• 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/8204790
• 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 Expression Profile; Gene Silencing; Genes; Goals; Golgi Apparatus; Growth; HDAC6 gene; 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; 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

PROJECT SUMMARY 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 eIF2¿, a component of the unfolded protein response (UPR) that mediates suppression of global protein synthesis. Specifically, PIs promote strong phosphorylation of eIF2¿ 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 eIF2¿. 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.

项目摘要 目前正在评估基于蛋白酶体抑制剂（PI）的联合化疗用于治疗 胰腺癌和其他实体恶性肿瘤。我们的假设是PI引起内质网（ER） 癌细胞中的压力，这种压力介导细胞杀伤。此外，我们已经获得初步证据 PI对细胞死亡的影响是高度异质性的，并且与它们是否诱导细胞死亡有关。 eIF2是未折叠蛋白反应（UPR）的一个组成部分，介导抑制 全球蛋白质合成具体来说，PI促进eIF2磷酸化的强烈磷酸化， 对PI诱导的细胞凋亡具有相对抗性的细胞系，但它们不能这样做（或减弱PI诱导的细胞凋亡）， 翻译）在最敏感的细胞系中。确定这种异质性的生化基础 能够前瞻性识别最有可能对基于PI的联合治疗产生反应的肿瘤 化疗，并应产生新的治疗干预的目标。我们还希望更好地界定 细胞凋亡的分子机制，这是由一个最有前途的PI为基础的， 组合方案，即硼替佐米加组蛋白脱乙酰酶（HDAC）抑制剂的组合。 我们已经获得了很好的初步证据，HDAC抑制剂促进蛋白酶体介导的 通过破坏细胞保护结构（称为侵袭体，其功能似乎是减轻ER）来诱导细胞凋亡 应力基因沉默研究表明，负责攻击基因组破坏的HDAC是 HDAC6抑制剂，并且更有选择性的HDAC6抑制剂可能会产生相当或更好的肿瘤细胞杀伤 比泛HDAC抑制剂（如SAHA）毒性更小。为了直接验证我们的假设，我们提出了 遵循具体目标。(1)定义控制硼替佐米诱导的 eIF2的磷酸化。我们将检验PI通过诱导PERK激活来抑制PERK激活的假设。 表达的分子伴侣（HSP 70？）阻断药物敏感细胞中的PERK同质聚集;（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诱导的细胞凋亡的影响;（3）：确定JNK、Noxa和caspase-4对PI诱导的细胞凋亡的毒性和抗肿瘤功效。 在异种移植物中使用PI和HDAC抑制剂的组合疗法。我们将比较 PI联合SAHA（泛HDAC抑制剂）、tubacin（HDAC 6选择性）或SNDX-275治疗 (type I HDAC特异性）在体外和来源于敏感性和抗性细胞系的原位肿瘤中。我们将 还研究药物-靶点相互作用和生物学反应的药效学标志物是否 可以在这些动物的外周血中测量，并应用这些方法测量 在胰腺癌患者中进行的II期临床试验背景下， 癌