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(PQ5) Relevance of VDAC2 heterogeneity for hepatic tumor growth and targeting

(PQ5) VDAC2 异质性与肝肿瘤生长和靶向的相关性

基本信息

批准号：
10395472
负责人：
Gyorgy Hajnoczky
金额：
$ 38.03万
依托单位：
THOMAS JEFFERSON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2018
资助国家：
美国
起止时间：
2018-05-22 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10395472
关键词：
Address Affect Anabolism Apoptosis Apoptotic BCL2 gene BH3 peptide Biochemical CRISPR/Cas technology Cancer Etiology Cell Culture Techniques Cell Death Cell Line Cell Survival Cells Cessation of life Chimeric Proteins Cytosol Databases Dependence Frequencies Functional Imaging Genetic Growth HepG2 Hepatic Hepatocyte Heterogeneity Human Hydrocarbons Immunofluorescence Immunologic Impairment Individual Injections Knock-out Knowledge Liver Liver neoplasms Luciferases MCL1 gene Malignant Epithelial Cell Malignant Neoplasms Malignant neoplasm of liver Mediating Medical Mitochondria Molecular Profiling Mus Normal Cell Outer Mitochondrial Membrane Pathway interactions Peptides Permeability Pharmaceutical Preparations Primary carcinoma of the liver cells Protein Family Proteins Proteomics Reporter Rodent Role Scheme Signal Transduction Surface Testing Therapeutic Tumor Cell Line Tumor-Derived Up-Regulation VDAC1 gene VDAC2 gene Voltage-Dependent Anion Channel bak protein cell type cytochrome c hepatoma cell imaging approach in vivo inhibitor inhibitor therapy microscopic imaging mimetics mutant neoplastic cell novel novel strategies overexpression patient derived xenograft model recruit tumor tumor growth tumor progression tumorigenesis voltage-dependent anion channel 2

项目摘要

PROJECT SUMMARY/ABSTRACT Liver cancers with increasing frequency in the world have become the second cause of cancer related death; however an important gap in current knowledge remains the molecular fingerprint and organization of hepatocarcinoma/hepatoma cells which might allow their specific targeting. We found that the expression level of two proteins, VDAC2 and Bak, that are central to a mitochondrial apoptosis pathway, is low in normal hepatocytes and is increased during hepatic tumor progression. Furthermore, we also found that the pro- apoptotic BH3-only Bcl-2 family protein, Bid induces mitochondrial apoptosis more efficiently in hepatocarcinoma than in normal liver. This difference can be eliminated by VDAC2 silencing in hepatocarcinoma cells, and by VDAC2 expression in normal hepatocytes but only if Bak isn’t knocked out. The potential medical significance of the VDAC2-Bak heterogeneity is supported by human databases that show upregulation of VDAC2 and Bak proteins in liver cancer. We have also documented both subcellular and cell- to-cell differences in the tBid-Bak pathway. Finally, we have shown at least in cell culture, that hepatocarcinoma cells can be selectively killed through the tBid-Bak pathway (using its activators and suppressors of its inhibitor, Mcl-1 while normal hepatocytes are spared. We here, postulate that the heterogeneity in VDAC2 and/or Bak abundance in the liver are important for hepatoma/ hepatocarcinoma (1) growth and (2) targeting by the combination of an Mcl-1 inhibitor drug and a cell permeable hydrocarbon stapled Bid BH3 peptide. Heterogeneity is considered (1) within the cells among individual mitochondria, (2) in each cell type among single cells, and (3) among the different cell types. To test our hypothesis we have established a combination of genetic targeting, tumorigenesis in mouse, and biochemical and microscopic imaging approaches. In the study we will focus on (1) assessing heterogeneity of VDAC2, Bak and Bak-mediated OMM permeabilization in hepatocarcinoma cells and normal hepatocytes and their dependence on VDAC2 expression and mitochondrial fusion; (2) determining whether increased expression of VDAC2 through upregulation of Bak affects hepatoma/hepatocarcinoma progression; (3) testing if activation of Bak by treatment with Mcl-1 inhibitor (S-63845) and a cell permeable hydrocarbon stapled Bid peptide can be used to kill hepatocyte-derived tumors without damaging normal hepatocytes; and (4) determining additional VDAC2-dependent proteins in hepatic tumor cells and to evaluate their heterogeneity in the liver and their relevance for hepatoma/hepatocarcinoma growth. By addressing these points, our study will provide clues to the contribution of mitochondrial heterogeneity to hepatic tumorigenesis and test a novel tumor-selective targeting approach.

项目总结/摘要肝癌在世界范围内的发病率不断上升，已成为癌症相关死亡的第二位原因; 然而，目前知识的一个重要空白仍然是分子指纹和组织，肝癌/肝癌细胞，这可能允许其特异性靶向。我们发现，两种蛋白质，VDAC 2和巴克，是核心的线粒体凋亡途径，是低的正常在肝肿瘤进展期间增加。此外，我们还发现，亲凋亡的BH 3-only Bcl-2家族蛋白，Bid诱导线粒体凋亡的效率更高，肝癌组高于正常组。这种差异可以通过VDAC 2沉默来消除，肝癌细胞中，以及正常肝细胞中VDAC 2的表达，但只有当巴克没有被敲除。的人类数据库支持VDAC 2-巴克异质性的潜在医学意义，肝癌中VDAC 2和巴克蛋白的上调。我们还记录了亚细胞和细胞- tBid-Bak途径中的细胞差异。最后，我们至少在细胞培养中证明，肝癌细胞可以通过tBid-Bak途径（使用其激活剂和其抑制剂Mcl-1的抑制剂，而正常肝细胞幸免。我们在这里，假设肝脏中VDAC 2和/或巴克丰度的异质性对于肝细胞瘤/ 通过Mcl-1抑制剂药物和细胞的组合抑制肝癌（1）生长和（2）靶向可渗透的烃钉合Bid BH 3肽。异源性被认为（1）在细胞内，单个线粒体中，（2）单个细胞中的每种细胞类型中，以及（3）不同细胞类型中。测试我们的假设是，我们已经建立了遗传靶向、小鼠肿瘤发生和生物化学和显微成像方法。在这项研究中，我们将重点放在（1）评估异质性，肝癌细胞和正常肝细胞中VDAC 2、巴克和巴克介导的OMM透化，它们对VDAC 2表达和线粒体融合的依赖性;（2）确定是否增加通过上调巴克表达VDAC 2影响肝癌/肝癌进展;（3）检测如果通过用Mcl-1抑制剂（S-63845）和细胞可渗透烃钉合Bid处理活化巴克肽可用于杀死肝细胞来源的肿瘤而不损伤正常肝细胞;和（4）确定肝肿瘤细胞中其他VDAC 2依赖性蛋白，并评价其在肝脏及其与肝癌/肝癌生长的相关性。通过解决这些问题，我们的研究将为线粒体异质性对肝肿瘤发生的贡献提供线索，并测试一种新的肿瘤选择性靶向方法。