Characterizing the signaling pathways that regulate Skp2 oncogenic function

表征调节 Skp2 致癌功能的信号通路

基本信息

批准号：
9172846
负责人：
Wenyi Wei
金额：
$ 39.57万
依托单位：
BETH ISRAEL DEACONESS MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-06-01 至 2021-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9172846
关键词：
Acetylation Affect Agreement Androgen Antagonists Androgens Antineoplastic Agents Automobile Driving Biochemical CCNE1 gene Cancer Patient Carcinoma Castration Cell Cycle Cell Cycle Progression Cell Line Cells Cellular Metabolic Process Citric Acid Cycle Clinical Cytoplasm Data Development Disease EP300 gene Ectopic Expression Engineering Enzymes Event Exhibits FOXO1A gene Glycolysis Growth Hormone Responsive Hormones Human In Vitro Knowledge LNCaP Lead Link Malignant Neoplasms Malignant neoplasm of prostate Mediating Metabolism Molecular Mus Neoplasm Metastasis Nude Mice Oncogenes Oncogenic Outcome Pharmacogenetics Phosphorylation Physiological Play Prostate Prostate Cancer therapy Prostate carcinoma Prostatic Neoplasms Proteins Regulation Reporting Resistance Role Signal Pathway Signal Transduction Substrate Specificity Testing Tetanus Helper Peptide Therapeutic Therapeutic Intervention Transgenic Mice Tumor Suppressor Proteins Ubiquitin Ubiquitination Withdrawal Work Xenograft Model Xenograft procedure abstracting base cancer type clinical application design in vivo inhibitor/antagonist insight mimetics mouse model mutant neoplastic cell novel novel strategies outcome forecast overexpression pre-clinical preclinical trial prostate cancer cell prostate cancer cell line prostate carcinogenesis response tumor tumor growth tumor metabolism tumor progression tumorigenesis tumorigenic ubiquitin-protein ligase

项目摘要

Abstract Skp2 is the substrate specificity factor of the SCFSkp2 E3 ligase involved in cell cycle progression through degradation of its ubiquitin targets such as p21, p27 and FOXO1. Since most of these substrates are tumor suppressor proteins, Skp2 functions as an oncogene and Skp2 overexpression is frequently observed in prostate carcinomas. However, the exact molecular mechanisms by which Skp2 induces prostate tumor growth and whether targeting Skp2 could be used as an efficient anti-prostate cancer therapy have not been fully elucidated. We recently reported that human Skp2 abundance and oncogenic functions are regulated by p300- mediated acetylation that could be antagonized by SIRT3. Moreover, expression of an acetylation-mimetic mutant of Skp2 promotes in vivo tumorigenesis in a xenograft model. We also obtained preliminary results showing that in multiple prostate cancer cell lines, Skp2 acetylation could be induced by androgen, and constitutive Skp2 acetylation might contribute to castration resistance while the underlying mechanism remains unclear. Furthermore, we identified IDH1 as a putative substrate of SCFSkp2, therefore revealing a novel role of Skp2 in cancer cell metabolism control that might underscore its oncogenic functions. Based on our preliminary data, we hypothesize that Skp2 oncogenic function is governed by acetylation, and aberrantly elevated Skp2 acetylation promotes prostate tumorigenesis and castration resistance in part by targeting downstream substrates such as IDH1 for degradation. Here, we intend to test our hypotheses by accomplishing three specific aims. In Aim #1, we will determine the molecular mechanisms by which the androgen/AR signaling pathway governs Skp2 oncogenic activity in the prostate cancer setting by regulating Skp2 acetylation. These studies will provide a novel mechanism on how androgen-induced acetylation of Skp2 regulates its oncogenic functions in the prostate cancer setting. It will also shed important insights into whether Skp2 acetylation could lead to the development of castration resistance. In Aim #2, we will examine whether acetylation of Skp2 could affect in vivo prostate cancer development using orthotopic and various engineered mouse models. These in vivo studies will significantly expand our knowledge of the regulation of Skp2 oncogenic functions by the p300/SIRT3 regulatory circuit. More importantly, we will carry out preclinical trials with MLN4924 and Skpin or compound #25 to examine if inhibiting Skp2 activity could efficiently retard in vivo prostate tumorigenesis and restore castration sensitivity. In Aim #3, we will determine the novel molecular mechanisms through which IDH1 stability is modulated by Skp2 in a Cdk2 and cell cycle dependent manner. Moreover, we will investigate whether inhibiting the Cdk2/Skp2 signaling axis could suppress prostate tumorigenesis in part by stabilizing IDH1. We believe that our proposed studies will not only provide a better molecular understanding of how Skp2 oncogenic activity is governed in vivo, but also provide direct evidence to evaluate if inactivating Skp2 could efficiently suppress prostate cancer development, leading to better treatment of this deadly disease.

抽象的 SKP2是参与细胞周期进程的SCFSKP2 E3连接酶的底物特异性因子其泛素靶标（例如P21，P27和FOXO1）的降解。由于这些底物大多数是肿瘤 SKP2抑制蛋白作为癌基因和SKP2过表达的作用，经常在前列腺癌。但是，SKP2诱导前列腺肿瘤生长的确切分子机制并且靶向SKP2是否可以用作有效的抗攻击癌疗法阐明。我们最近报道说，人类SKP2丰度和致癌功能受P300-的调节介导的乙酰化可以被SIRT3拮抗。此外，乙酰化模拟的表达 SKP2的突变体促进异种移植模型中的体内肿瘤发生。我们还获得了初步结果表明在多个前列腺癌细胞系中，SKP2乙酰化可以由雄激素诱导，并且本构SKP2乙酰化可能有助于cast割耐药性，而潜在的机制仍然存在不清楚。此外，我们将IDH1确定为SCFSKP2的推定底物，因此揭示了一种新颖的作用癌细胞代谢控制中的SKP2可能强调其致癌功能。基于我们的初步数据，我们假设SKP2致癌功能受乙酰化的控制，并且SKP2异常升高乙酰化通过靶向下游来促进前列腺肿瘤发生和castration耐药性诸如IDH1之类的底物降解。在这里，我们打算通过完成三个来检验我们的假设具体目标。在AIM＃1中，我们将确定雄激素/AR信号传导的分子机制途径通过调节SKP2乙酰化来控制前列腺癌设置中的SKP2致癌活性。这些研究将提供一种有关雄激素诱导的SKP2乙酰化如何调节其致癌的新机制在前列腺癌设置中的功能。它还将对SKP2乙酰化是否可以导致cast割抵抗的发展。在AIM＃2中，我们将检查SKP2的乙酰化是否可以使用原位和各种工程小鼠模型影响体内前列腺癌发展。这些体内研究将大大扩展我们对SKP2致癌功能调节的了解 P300/SIRT3监管电路。更重要的是，我们将使用MLN4924和SKPIN或SKPIN或 25化合物检查抑制SKP2活性是否可以有效地延迟体内前列腺肿瘤发生和恢复cast割灵敏度。在AIM＃3中，我们将确定新颖的分子机制 IDH1稳定性由SKP2以CDK2和细胞周期依赖性方式调节。而且，我们将调查抑制CDK2/SKP2信号轴是否可以通过稳定来抑制前列腺肿瘤发生 IDH1。我们认为，我们提出的研究不仅将对SKP2的方式提供更好的分子理解致癌活性是在体内控制的，但也提供了直接的证据来评估灭活SKP2是否可以有效抑制前列腺癌的发展，从而更好地治疗这种致命疾病。