(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.

项目摘要/摘要世界上频率越来越多的肝癌已成为癌症相关死亡的第二个原因。但是，当前知识的重要差距仍然是分子指纹和组织肝癌/肝癌细胞可能允许其特定靶向。我们发现表达水平在正常情况下，两种蛋白质VDAC2和BAK是线粒体凋亡途径的核心肝细胞并在肝肿瘤进展过程中增加。此外，我们还发现仅凋亡BH3-仅BCl-2家族蛋白，出价诱导的线粒体细胞凋亡在肝癌比正常肝脏中。 VDAC2沉默可以消除这种差异肝癌细胞，以及通过正常肝细胞中的VDAC2表达，但前提是没有被淘汰。这人类数据库支持VDAC2-BAK异质性的潜在医学意义肝癌中VDAC2和BAK蛋白的上调。我们还记录了亚细胞和细胞 TBID-BAK途径的待办事项差异。最后，我们至少在细胞培养中表明了可以通过TBID-BAK途径选择性地杀死肝癌细胞（使用其激活剂和其抑制剂的倡导者MCL-1虽然遗憾正常的肝细胞。我们在这里，假设 VDAC2和/或BAK抽象中的异质性对于肝瘤/ 肝癌（1）生长和（2）通过MCL-1抑制剂和细胞组合靶向靶向可渗透的碳氢化合物分期出价BH3 Pepperide。在细胞中考虑（1）的异质性单个细胞中每种细胞类型中的单个线粒体，（2），（3）在不同的细胞类型中。测试我们的假设我们已经建立了遗传靶向，小鼠肿瘤发生的结合，生化和微观成像方法。在研究中，我们将重点介绍（1）评估异质性 VDAC2，BAK和BAK介导的肝癌细胞和正常肝细胞中的OMM通透性它们对VDAC2表达和线粒体融合的依赖；（2）确定是否增加 VDAC2通过上调的表达会影响肝癌/肝癌的进展。（3）测试如果用Mcl-1抑制剂（S-63845）和可渗透碳氢化合物分阶段的BID激活BAK 肽可用于杀死肝细胞衍生的肿瘤，而不会损害正常的肝细胞。（4）确定肝肿瘤细胞中的其他VDAC2依赖性蛋白质，并评估其异质性肝脏及其与肝癌/肝癌生长的相关性。通过解决这些观点，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肿瘤选择性靶向方法。