Targeting Endoplasmic Reticulum Stress Response for Cancer Therapy

靶向内质网应激反应进行癌症治疗

• 批准号: 8685183
• 负责人: BERTAL H. AKTAS
• 金额: $ 34.47万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2016-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8685183
• 关键词: Acute; Affect; Animals; Bilateral; Binding Proteins; Biogenesis; Blood; Blood Chemical Analysis; Blood Vessels; Boxing; Cancer cell line; Carrier Proteins; Cell Line; Cell Proliferation; Cells; Cellular Stress; Chemical Agents; Chemicals; Chemistry; Code; Computer software; Cytostatics; Dose; Drug Kinetics; Endoplasmic Reticulum; Eukaryotic Initiation Factors; Failure; Funding; Genes; Genetic Engineering; Genetic Transcription; Goals; Histopathology; Homeostasis; Human; Hypoxia; In Vitro; Injection of therapeutic agent; Inositol; Introns; Lead; Malignant - descriptor; Malignant Neoplasms; Measures; Messenger RNA; Metabolism; Molecular Chaperones; Molecular Weight; Mus; Neoplasm Metastasis; Nutrient; Open Reading Frames; Oxygen; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Plasma; Positioning Attribute; Prokaryotic Initiation Factor-2; Protein Biosynthesis; Protein S; Proteins; RNA Splicing; Recombinants; Recruitment Activity; Resistance; Side; Solid Neoplasm; Specificity; Surface; Testing; Thiourea; Time; Toxic effect; Transgenic Organisms; Translation Initiation; Work; activating transcription factor; arm; base; biological adaptation to stress; cancer cell; cancer therapy; chemical genetics; cytotoxic; drug development; efficacy testing; endoplasmic reticulum stress; food consumption; indexing; inhibitor/antagonist; killings; malignant breast neoplasm; mutant; neoplastic cell; novel; oxindole; programs; prostate cancer cell; protein degradation; protein kinase R; protein transport; tool; transcription factor; tumor; tumor growth

DESCRIPTION (provided by applicant): The overall goal of this proposal is to test the hypothesis that IERSR can be pharmacologically targeted for cancer therapy. Solid tumors are poorly vascularized and therefore cannot receive sufficient oxygen and nutrients particularly in the least vascularized regions. This causes accumulation of unfolded proteins in endoplasmic reticulum (ER), termed ER-stress. Activation of integrated ER-stress response (IERSR) critically contributes to tumor growth and survival. The IERSR involves inhibiting translation initiation to reduce the demand on the folding capacity of the ER and activating a transcription program to enlarge the size and the folding capacity of the ER. Translation initiation is inhibited through activation of protein kinase R (PKR)-like ER resident kinase PERK and phosphorylation of eukaryotic translation initiation factor 2 aplha (eIF2a). The transcription program to increase the size and the folding capacity of the ER is accomplished by activating key transcription factors such as X box binding protein-1 Xbp-1 that control expression of ER-chaperons, ER biogenesis and ER-associated retrograde protein transport and degradation genes. However, IERSR must be regulated in a spatial and temporal manner because either the failure to activate IERSR or sustained activation of IERSR will reduce survival of stressed cells. We hypothesize that tumor cells utilize IERSR in a spatially and temporally regulated manner to survive ER-stress or avoid the cytostatic and cytotoxic effects of prolonged IERSR. We further hypothesize that limiting the ability of tumors to activate IERSR or causing sustained and exaggerated IERSR will cause selective demise of tumors. We have developed chemical modulators of the IERSR and genetically engineered human cancer cells lines resistant to these agents. If this proposal is funded, we will utilize our transgenic cell lines and chemical modulators of IERSR to test our hypothesis and to determine conclusively if the IERSR can be pharmacologically targeted for cancer therapy. 1) We will test the hypothesis that N,N'-diarylurea induced sustained eIF2a phosphorylation will inhibit tumor growth. We will study the pharmacokinetic profile and acute toxicity of selected/optimized N,N'-diarylureas. We will determine their efficacy and mechanism specificity by treating mice carrying bilateral tumors expressing eIF2a-WT on one side and non-phosphorylatable mutant, eIF2a-S51A on the other side (Specific Aim 1). 2) We will test the hypothesis that inhibition of Xbp-1 splicing by diaryl-oxindoles inhibit tumor growth by studying the pharmacokinetic profile and acute toxicity of selected/optimized diaryl-oxindole. We will determine their efficacy and mechanism specificity by treating mice carrying bilateral tumors expressing only endogenous Xbp-1 on one side and already spliced Xbp-1 on the other side (Specific Aim 2), and 3) We will test the hypothesis that inhibition of Xbp-1 splicing and induction of eIF2a phosphorylation will synergistically inhibit tumor growth and metastasis (Specific Aim 3).

描述（由申请人提供）：该提案的总体目标是检验 IERSR 可以作为癌症治疗的药理学靶向的假设。实体瘤的血管化程度较差，因此无法获得足够的氧气和营养，特别是在血管化最少的区域。这会导致未折叠蛋白在内质网 (ER) 中积累，称为 ER 应激。整合内质网应激反应 (IERSR) 的激活对于肿瘤的生长和存活至关重要。 IERSR 涉及抑制翻译起始以减少对 ER 折叠能力的需求，并激活转录程序以扩大 ER 的大小和折叠能力。通过激活蛋白激酶 R (PKR) 样 ER 驻留激酶 PERK 和磷酸化真核翻译起始因子 2 aplha (eIF2a) 来抑制翻译起始。增加 ER 大小和折叠能力的转录程序是通过激活关键转录因子来完成的，例如控制 ER 伴侣表达、ER 生物合成和 ER 相关逆行蛋白转运的 X box 结合蛋白-1 Xbp-1，以及降解基因。然而，IERSR 必须以空间和时间的方式进行调节，因为 IERSR 未能激活或 IERSR 持续激活都会降低应激细胞的存活率。我们假设肿瘤细胞以空间和时间调节的方式利用 IERSR 来抵抗 ER 应激或避免长期 IERSR 的细胞抑制和细胞毒性作用。我们进一步假设限制肿瘤激活 IERSR 的能力或引起持续和夸大的 IERSR 将导致肿瘤选择性死亡。我们开发了 IERSR 的化学调节剂和对这些药物具有抗性的基因工程人类癌细胞系。如果这项提案获得资助，我们将利用我们的转基因细胞系和 IERSR 的化学调节剂来测试我们的假设，并最终确定 IERSR 是否可以作为癌症治疗的药理学目标。 1) 我们将检验 N,N'-二芳基脲诱导的持续 eIF2a 磷酸化将抑制肿瘤生长的假设。我们将研究选定/优化的 N,N'-二芳基脲的药代动力学特征和急性毒性。我们将通过治疗一侧表达 eIF2a-WT 且另一侧表达非磷酸化突变体 eIF2a-S51A 的双侧肿瘤小鼠来确定其功效和机制特异性（具体目标 1）。 2) 我们将通过研究选定/优化的二芳基-羟吲哚的药代动力学特征和急性毒性来测试二芳基-羟吲哚抑制Xbp-1剪接抑制肿瘤生长的假设。我们将通过治疗携带一侧仅表达内源性 Xbp-1 且另一侧已剪接 Xbp-1 的双侧肿瘤的小鼠来确定其功效和机制特异性（具体目标 2）和 3）我们将测试抑制Xbp-1 剪接和诱导 eIF2a 磷酸化将协同抑制肿瘤生长和转移（具体目标 3）。