Targeting GRP78 for p53 activation as anti-cancer therapy

靶向 GRP78 激活 p53 作为抗癌疗法

基本信息

批准号：
9008031
负责人：
Hua Lu
金额：
$ 16.37万
依托单位：
TULANE UNIVERSITY OF LOUISIANA
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-03-01 至 2018-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9008031
关键词：
Address Affinity Chromatography Antineoplastic Agents Apoptosis Apoptotic Area Binding Biochemical Biological Assay Biotin Bortezomib Cancer Cell Growth Cancer Model Cell Cycle Arrest Cell Nucleus Cell Survival Cell surface Cells Clinic Colon Combined Modality Therapy Coupled DNA Repair Deacetylase Defect Development Disease Endoplasmic Reticulum Flow Cytometry Fluorescence Microscopy Future GRP78 gene Genome Stability Goals Growth Health Homeostasis Human In Vitro Investigation Investments Label Lung Maintenance Malignant Neoplasms Malignant neoplasm of lung Mass Spectrum Analysis Measures Mediating Molecular Chaperones Mutation Names Nelfinavir Neoplasm Metastasis Normal Cell Nuclear Translocation Pathway interactions Pharmacologic Substance Play Prevention Process Production Protein p53 Proteins Quality Control Role Signal Transduction Stress TP53 gene Testing Transcriptional Activation Tumor Angiogenesis Tumor Suppression Tumor Suppressor Proteins Xenograft procedure anticancer activity anticancer research biophysical techniques cancer cell cancer therapy celecoxib drug discovery endoplasmic reticulum stress glucose-regulated proteins improved insight mortality mouse model neoplastic cell novel p53 Signaling Pathway protein folding research and development response senescence small molecule therapy development therapy resistant tool tumor tumor growth tumor progression uptake

项目摘要

DESCRIPTION (provided by applicant): Despite numerous major scientific breakthroughs and tremendous R&D investments in the pharmaceutical sector over the past 3 decades, cancer still is the leading cause of disease-related mortality and awaits further advances toward improved therapy. Intensive effort has been focusing on the tumor suppressor p53 pathway because nearly all cancers show defects in this pathway, over 50% of which have mutations in the TP53 gene itself. We recently discovered Inauhzin (INZ) as a novel non-genotoxic p53 activator. INZ activates p53 by targeting SIRT1 and consequently suppresses tumor growth. In our ongoing studies to explore other possible targets of this compound, we identified a 78-kDa glucose-regulated protein (GRP78, also called BiP) as one of the top INZ target candidates. GRP78 is traditionally regarded as a major endoplasmic reticulum (ER) chaperone and a master regulator of the unfolded protein response (UPR) facilitating protein folding and assembly, protein quality control and regulating ER stress (ERS) signaling. Recent advances using mouse models and cellular approaches have revealed that GRP78 also functions beyond the ER. This discovery is not only critical for better understanding the unique and essential role of GRP78 in cancer development and prevention, but also offers an opportunity for cancer-specific targeting. Interestingly and surprisingly, we have also found that INZ can trigger the nuclear translocation of GRP78 that co-localized with accumulated p53 in the nucleus of cancer cells. Our finding suggests that INZ may regulate GRP78 through mechanisms distinct from the ERS-UPR pathway. Hence, the objectives of this application are to validate GRP78 as another bona fide target of INZ and to elucidate the mechanism underlying the role of GRP78 in INZ-induced p53 activation and anticancer activities. Our central hypothesis is that GRP78 is the direct tumor-specific target for INZ, leading to ER-independent activation of the p53 signaling pathway in cancer, but not normal, cells, and the combination of clinically used ERS/UPR-associated modulators with the p53 activator INZ may be a successful approach for overcoming chemoresistance and eliminating tumors. We will test this hypothesis by addressing the following Specific Aims: (1) to biochemically and biophysically characterize the specific binding of INZ to GRP78 in vitro and in cells; (2) to determine the role of cell-surface GRP78 in INZ uptake and specific cancer targeting, to determine how GRP78 is imported from ER to the nucleus by INZ to mediate p53 activation, and to evaluate the synergistic effect of INZ with clinically used ERS/UPR-associated modulators. Should our exploratory studies demonstrate GRP78 as a cancer specific target for INZ through an ER-independent p53 activation, this would not only provide proof-of-concept evidence for targeting both of the ER Stress/UPR related and p53 signaling pathways for cancer therapy, but would also offer new insights into the role of GRP78 in cancer development and therapy and have a strong impact on the area of molecule-specific anti- cancer drug discovery, particularly in the field of translational cancer research.

描述（由申请人提供）：尽管过去三十年制药领域取得了许多重大科学突破和巨大的研发投资，但癌症仍然是疾病相关死亡的主要原因，并且有待进一步改进治疗方法。人们一直在集中精力研究肿瘤抑制因子 p53 通路，因为几乎所有癌症都显示出该通路的缺陷，其中超过 50% 的癌症在 TP53 基因本身中存在突变。我们最近发现 Inauhzin (INZ) 作为一种新型非基因毒性 p53 激活剂。 INZ 通过靶向 SIRT1 激活 p53，从而抑制肿瘤生长。在我们正在进行的探索该化合物其他可能靶点的研究中，我们确定了 78-kDa 葡萄糖调节蛋白（GRP78，也称为 BiP）作为 INZ 的顶级候选靶点之一。 GRP78 传统上被认为是主要的内质网 (ER) 伴侣和未折叠蛋白反应 (UPR) 的主要调节因子，促进蛋白质折叠和组装、蛋白质质量控制和调节 ER 应激 (ERS) 信号传导。使用小鼠模型和细胞方法的最新进展表明，GRP78 的功能也超出了 ER。这一发现不仅对于更好地了解 GRP78 在癌症发展和预防中的独特而重要的作用至关重要，而且还为癌症特异性靶向提供了机会。有趣且令人惊讶的是，我们还发现INZ可以触发GRP78的核转位，GRP78与癌细胞核中积累的p53共定位。我们的研究结果表明，INZ 可能通过不同于 ERS-UPR 途径的机制来调节 GRP78。因此，本申请的目的是验证 GRP78 作为 INZ 的另一个真正靶标，并阐明 GRP78 在 INZ 诱导的 p53 激活和抗癌活性中的作用机制。我们的中心假设是 GRP78 是 INZ 的直接肿瘤特异性靶标，导致癌症细胞（而非正常细胞）中 p53 信号通路的 ER 依赖性激活，以及临床使用的 ERS/UPR 相关调节剂与p53 激活剂 INZ 可能是克服化疗耐药性和消除肿瘤的成功方法。我们将通过解决以下具体目标来检验这一假设：（1）在体外和细胞中从生化和生物物理角度表征 INZ 与 GRP78 的特异性结合；（2）确定细胞表面GRP78在INZ摄取和特异性癌症靶向中的作用，确定INZ如何将GRP78从ER导入细胞核介导p53激活，并评估INZ与临床使用的ERS的协同作用/UPR 相关调节剂。如果我们的探索性研究证明 GRP78 通过独立于 ER 的 p53 激活而成为 INZ 的癌症特异性靶标，那么这不仅可以为癌症治疗的靶向 ER 应激/UPR 相关信号通路和 p53 信号通路提供概念验证证据，但也将为 GRP78 在癌症发展和治疗中的作用提供新的见解，并对分子特异性抗癌药物发现领域产生重大影响，特别是在转化癌症研究领域。