Autophagy, mTOR inhibitors and phenformin in hepatocellular carcinoma

肝细胞癌中的自噬、mTOR 抑制剂和苯乙双胍

基本信息

批准号：
8957211
负责人：
Carol Mercer
金额：
$ 22.17万
依托单位：
UNIVERSITY OF CINCINNATI
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：
2015-06-01 至 2017-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8957211
关键词：
5&apos -AMP-activated protein kinase Address Agreement Autophagocytosis BAY 54-9085 Biguanides Cancer Etiology Cancer Patient Cancer Prognosis Cell Proliferation Cell Survival Cells Cessation of life Clinical Complex Cultured Cells Data Diagnosis Disease Down-Regulation Drug Targeting Eating Epidemic Future Gap Junctions Genes Genetic Goals Growth Hepatitis Hormonal Human Implant Incidence Link Liver Liver neoplasms Malignant Neoplasms Malignant neoplasm of liver Measures Mediating Metformin Microarray Analysis Mitochondria Modeling Molecular Mus North America Nutrient Obesity Organoids Pathway interactions Patients Pharmaceutical Preparations Phenformin Phosphorylation Phosphotransferases Population Primary Neoplasm Primary carcinoma of the liver cells Process Proliferating Protein Kinase Regimen Reporting Role Signal Pathway Signal Transduction Sirolimus Site Societies Staging Testing Therapeutic Transplantation Tumor Suppressor Proteins advanced disease cancer cell cancer stem cell cancer therapy improved in vivo inhibition of autophagy inhibitor/antagonist killings mTOR protein mouse model neoplastic cell non-alcoholic nonalcoholic steatohepatitis outcome forecast pre-clinical prevent public health relevance response stem success tumor tumor growth tumorigenic

项目摘要

DESCRIPTION (provided by applicant): In 2012, liver cancer was the second most common cause of cancer deaths worldwide. The incidence of hepatocellular cancer (HCC) is increasing, particularly in western societies where it is linked to the growing epidemic of obesity. Despite recent advances with targeted drugs like sorafenib, the prognosis for HCC patients with advanced disease remains poor, highlighting the urgent need for new therapies. The mammalian target of rapamycin (mTOR) protein kinase is a promising target in HCC, as the mTOR pathway has been shown to be upregulated in ~50% of HCCs, and the mTOR allosteric inhibitor rapamycin has been shown to inhibit tumor growth. However, the clinical use of rapamycin in HCC has had limited success, in agreement with our preclinical data using the rapamycin RAD001 in a mouse model of HCC. In the same study we found that RAD001 in combination with the dual PI3K/mTOR inhibitor BEZ235 synergistically inhibited mTOR signaling and growth of HCC tumors, which correlated with increased mitophagy. This finding is consistent with genetic data showing that autophagy in liver may act as a tumor suppressor. However, it was recently reported that mTOR inhibitors promote the survival of CD133+ HCC stem-like cells (HSCs), presumably through increased autophagy. Despite this observation, the biguanides phenformin and metformin, which activate AMPK, an upstream regulator of unc-51 like kinase (ULK1) and autophagy, are reported to selectively suppress cancer stem cells. In preliminary studies, we set out to compare the extent of autophagy induction in cells treated with RAD001/BEZ235 to those treated with phenformin, and the effects of the two treatments on the survival of HSCs. Unexpectedly, we found that phenformin not only failed to induce autophagy on its own, but inhibited RAD001/BEZ235 induced autophagy. Consistent with earlier reports, RAD001/BEZ235 treatment promoted the survival of HSCs in organoids derived from liver tumors, which was reversed by phenformin. These findings have led us to hypothesize that treatment of HCC with combined allosteric and ATP-site competitive inhibitors (mTOR paired inhibitors) effectively prevents bulk tumor growth, but promotes the autophagic-dependent survival of HSCs, which are sensitive to phenformin through the inhibition of autophagy, which we will test in two aims. In Aim 1, we will determine the mechanism by which phenformin inhibits autophagy and the relationship between autophagy and cellular energy status. We will determine the step(s) of autophagy inhibited by phenformin and the role of AMPK in regulating this response. In Aim 2, we will determine the therapeutic advantage of combining phenformin with mTOR paired inhibitors in HCC, when given together or sequentially. We will treat human HSCs and mouse HSC derived multi-population organoids with mTOR paired inhibitors with or without phenformin to test their therapeutic responsiveness. The ex vivo results will be compared to treatment of HCC tumor-bearing mice, with the goal of utilizing human HCC-derived organoids for future therapeutic applications.

描述（由适用提供）：2012年，肝癌是全球癌症死亡的第二大最常见原因。肝细胞癌（HCC）的事件正在增加，特别是在西方社会与肥胖流行病有关的西方社会。尽管索拉非尼（Sorafenib）等有针对性的药物最近进展，但HCC患者的预后仍然很差，这突出了对新疗法的迫切需求。雷帕霉素（MTOR）蛋白激酶的哺乳动物靶标在HCC中是一个有前途的靶标，因为已显示MTOR途径在〜50％的HCC中进行了更新，并且已显示MTOR变构抑制剂雷帕霉素已被证明可抑制肿瘤的生长。然而，雷帕霉素在HCC中的临床使用取得了有限的成功，与我们使用雷帕霉素RAD001的临床前数据一致。在同一项研究中，我们发现RAD001与双PI3K/MTOR抑制剂BEZ235共同抑制了MTOR信号传导和HCC肿瘤的生长，这与线粒体的增加相关。这一发现与遗传数据一致，表明肝脏中的自噬可能充当肿瘤抑制因子。然而，最近有报道称，MTOR抑制剂促进了CD133+ HCC样细胞（HSC）的存活，大概是通过自噬增加的。尽管有这样的观察，但据报道，激活AMPK的Biguanides苯甲酸苯甲酸苯甲酸脂蛋白和二甲双胍是UNC-51的上游调节剂（例如激酶（ULK1）和自噬），可有选择地抑制癌症干细胞。在初步研究中，我们着手将用RAD001/BEZ235处理的细胞中的自噬诱导程度与接受苯甲酸苯甲酸苯甲酸苯甲呈蛋白治疗的细胞以及两种处理对HSC生存的影响。出乎意料的是，我们发现苯甲型不仅没有自行诱导自噬，而且抑制了RAD001/BEZ235诱导的自噬。与较早的报道一致，RAD001/BEZ235治疗促进了源自肝肿瘤的类器官中HSC的存活，该器官被苯甲甲蛋白逆转。这些发现使我们假设用组合的变构和ATP现场竞争抑制剂（MTOR配对抑制剂）有效地预防了HSC的HSC生存率，从而可以通过自动噬菌体的抑制作用，这将在两次攻击中测试，这是对苯有胺敏感的，从而促进了HSC的自动噬菌体生存。在AIM 1中，我们将确定苯甲酸苯甲甲型抑制自噬以及自噬和细胞能量状态之间的关系的机制。我们将确定由苯甲酸苯甲酸苯甲酸苯甲酸苯酚抑制的自噬的步骤以及AMPK在调节这种反应中的作用。在AIM 2中，我们将确定将苯甲酸苯甲甲型与HCC中MTOR配对抑制剂组合在一起时的治疗优势。我们将使用MTOR成对的抑制剂或不带有下甲呈蛋白的MTOR配对抑制剂来处理人类HSC和小鼠HSC衍生的多人种类器官，以测试其治疗性反应性。离体结果将与对HCC肿瘤小鼠的治疗进行比较，其目的是利用人类HCC衍生的类器官进行未来的治疗应用。