Dual Targeting of the p53 pathway for development of anti-cancer therapy

双重靶向 p53 通路以开发抗癌疗法

基本信息

批准号：
9102015
负责人：
Hua Lu
金额：
$ 31.27万
依托单位：
TULANE UNIVERSITY OF LOUISIANA
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-09-26 至 2018-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9102015
关键词：
A549 Acetylation Address Adult Adverse effects Affect Animals Antineoplastic Agents Apoptosis Autophagocytosis Binding Biochemical Biological Models Cancer Patient Cell Cycle Cell Survival Cells Cessation of life Colon Carcinoma Colonic Neoplasms Complex Country Deacetylase Deacetylation Development Disease Down-Regulation Doxorubicin Enzyme Inhibition Feedback Foundations Gene Mutation Gene Targeting Genes Growth Guanosine Triphosphate H1299 HCT116 Cells Histone Deacetylase Human Implant Inosine Monophosphate Inosine Monophosphate Dehydrogenase Inhibitor Laboratories Light Lung Neoplasms MCF7 cell MDM2 gene Malignant Neoplasms Malignant neoplasm of lung Mediating MicroRNAs Modeling Molecular Mus Mutate Names Oxidoreductase Pathway interactions Patients Process Protein p53 Proteins Public Health Publishing Radiation therapy Regulation Reporting Ribosomal Proteins Ribosomal RNA Role Solid Stress Survival Rate TP53 gene Testing Tumor Suppression Tumor Suppressor Proteins Tumor-Derived Ubiquitin Ubiquitination Work Wound Healing Xenograft procedure analog cancer cell cancer imaging cancer therapy cell growth cellular targeting chemotherapy drug candidate improved interest irradiation member novel overexpression research study response senescence small molecule success targeted treatment tumor tumor growth

项目摘要

DESCRIPTION (provided by applicant): Cancer has been the leading cause of disease-related deaths in human beings, yet, its major non-surgery treatments have been chemotherapy and radiotherapy, both of which are quite toxic and cause severe side effects. Also, the survival rates of cancer patients have had little improvement. Thus, it still remains remarkably important, though challenging, to develop more potent and specific molecule-targeted therapies. The inactivation of the most important tumor suppressor p53 is one highly cancer-related molecular alteration, as its gene is mutated in ~50% of all types of human cancers while its activity or leve is often markedly reduced in the remaining 50% of cancers that harbor wild type TP53. The p53 deactivation is primarily due to the negative feedback regulation by its two chief suppressors, MDM2 and MDMX, which are over expressed in cancers and form a complex that mediates p53 ubiquitination and degradation as well as inhibits p53 activity directly. This negative regulation s further facilitated by SIRT1, which is highly expressed in some cancers, as the deacetylation of p53 by this deacetylase favors MDM2/MDMX-mediated ubiquitination of this protein. Thus, re-activation of p53 in cancers by targeting SIRT1 can be utilized to screen small molecules for the development of an anti-cancer therapy. Indeed, our recent work has identified a small molecule named Inauhzin (INZ) that inhibits the activity of SIRT1 and induces p53 acetylation, level and activity, leading to p53-dependent apoptosis and senescence in p53-containing human lung and colon cancer cells and suppressing the growth of xenograft lung and colon tumors. Our further studying INZ surprisingly reveals another target, IMPDH2, which is also highly expressed in human cancers. Our previous study shows that inhibition of this enzyme causes ribosomal stress by reducing the level of nucleostemin (NS), which is essential for rRNA processing. Consistent with this, INZ also binds to IMPDH2 and reduces NS levels, leading to the activation of the ribosomal stress-p53 pathway. In light of these interesting findings, I hypothesize that INZ can activate p53 by simultaneously targeting SIRT1 and IMPDH2 and thus eliminate cancer cells via a p53-dependent mechanism. We will test this hypothesis by addressing two specific aims. 1. To determine if INZ induces ribosomal stress and activates p53 by inhibiting IMPDH2 and downregulating NS. Since we have recently reported that INZ inhibits SIRT1 activity, here in this aim we will determine if INZ targets IMPDH2 by verifying INZ as a specific inhibitor of IMPDH2, consolidating if inhibition of IMPDH2 by INZ reduces NS levels and induces consequent ribosomal stress, and determining if RPL11 and RPL5 are critical for INZ-induced p53 activation. 2. To determine the role of INZ-14, a more potent INZ analog, in p53 activation and tumor suppression. In this aim, we will test our newly synthesized INZ derivatives, particularly potent INZ-14, by further modifying it, characterizing it in our established biochemical, cellular and animal tumor model systems, and testing the cooperative effect of INZ-14 with doxorubicin or �-irradiation in xenograft and orthotopic tumor model systems.

描述（由适用提供）：癌症一直是人类与疾病相关的死亡的主要原因，但是，其主要的非手术治疗方法是化学疗法和放疗，这两种疗法都非常有毒，并且会引起严重的副作用。而且，癌症患者的存活率几乎没有改善。这仍然非常重要，尽管挑战是开发更多的潜在和特定的靶向分子疗法。最重要的肿瘤抑制p53的失活是一种高度癌症相关的分子改变，因为其基因在所有类型的人类癌症的约50％中被突变，而其活性或水平通常在其余50％的携带TP53的癌症中显着降低。 p53停用主要是由于其两种主要补充剂MDM2和MDMX的负反馈调节，它们在癌症中过度表达，并形成一种复合物，该复合物介导了p53泛素化和降解以及直接抑制p53活性。 SIRT1进一步制备了这种负调节，在某些癌症中高度表达，因为该脱乙酰基酶对p53的脱乙酰化偏爱MDM2/MDMX介导的该蛋白的泛素化。这是通过靶向SIRT1在癌症中重新激活p53，可用于筛选小分子以开发抗癌疗法。实际上，我们最近的工作已经确定了一个名为Inauhzin（INZ）的小分子，该分子抑制了SIRT1的活性并影响p53乙酰化，水平和活性，从而导致p53依赖性凋亡和p53含有p53的人类肺癌和结肠癌细胞的感受，并抑制盐诺夫妇和结肠瘤的生长。我们进一步的研究INZ令人惊讶地揭示了另一个目标，即在人类癌症中也高度表达。我们先前的研究表明，对这种酶的抑制会通过降低核系统蛋白（NS）的水平来引起核糖体应激，这对于RRNA处理至关重要。与此相一致，INZ还与IMPDH2结合并降低了NS水平，从而导致核糖体应力P53途径的激活。鉴于这些有趣的发现，我假设Inz 可以通过简单地靶向SIRT1和IMPDH2来激活p53，从而通过p53依赖机制消除癌细胞。我们将通过解决两个具体目标来检验这一假设。 1。确定INZ是否通过抑制IMPDH2和下调NS来影响核糖体应激并激活p53。 Since we have recently reported that INZ inhibits SIRT1 activity, here in this aim we will determine if INZ targets IMPDH2 by verifying INZ as a specific inhibitor of IMPDH2, consolidating if inhibition of IMPDH2 by INZ reduces NS levels and induces consequent ribosomal stress, and determining if RPL11 and RPL5 are critical for INZ-induced p53 activation. 2。为了确定INZ-14的作用，INZ-14的作用是p53激活和抑制肿瘤中的潜在INZ类似物。为此，我们将通过进一步修改它来测试我们新合成的INZ衍生物，尤其是潜在的INZ-14，并在我们已建立的生化，细胞和动物肿瘤模型系统中表征它，并测试INZ-14与阿霉素或纽也摩raft虫抗逆转录型和植物植物和外生型tumor模型系统的合作效应。