RNA Binding Proteins in Cancer

癌症中的 RNA 结合蛋白

• 批准号: 8018162
• 负责人: Shrikant Anant
• 金额: $ 30.19万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2014-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8018162
• 关键词: 3' Untranslated Regions; Affinity; Anchorage-Independent Growth; Apoptosis; Behavior; Binding; Binding Sites; C-terminal; Cancer Model; Cause of Death; Cell Death; Cell Survival; Cells; Colon Carcinoma; Consensus; Deletion Mutation; Disease; Elements; Epidermal Growth Factor; Epithelial Cells; Gene Expression; Gene Expression Regulation; Genetic Translation; Glycine; Goals; Growth; Health; Interleukin-8; Intestines; Lead; Malignant Neoplasms; Manuscripts; Mediating; Messenger RNA; Methods; MicroRNAs; Mitosis; Mitotic; Modification; Mus; Mutagenesis; N-terminal; Normal Cell; Nude Mice; Pathway interactions; Phenotype; Phosphorylation; Post-Transcriptional Regulation; Process; Promoter Regions; Protein Binding; Protein Overexpression; Proteins; Proto-Oncogenes; Publishing; RNA Binding; RNA Recognition Motif; RNA Sequences; RNA Stability; RNA-Binding Proteins; Ribonucleoproteins; Ribosomes; Role; Serine; Signal Pathway; Site; Threonine; Transcript; Transcriptional Activation; Translations; Tyrosine Phosphorylation Site; Ubiquitination; United States; Vascular Endothelial Growth Factors; Work; Xenograft procedure; base; cancer cell; cyclooxygenase 2; deletion analysis; human FRAP1 protein; mRNA Decay; mRNA Stability; mTOR protein; mutant; neoplastic cell; notch protein; novel; overexpression; promoter; research study; tumor; tumor xenograft; tumorigenesis

DESCRIPTION (provided by applicant): The broad goal of the project is to understand the mechanisms by which RNA binding protein RBM3 regulates gene expression at the posttranscriptional level of mRNA stability and translation in cancer cells. We have identified that overexpression of the protein causes a normal cell to undergo a transformed phenotype resulting in the cells forming tumors in immunocompromized mice. On the other hand, knockdown of RBM3 expression results in cell death due to mitotic catastrophe. RBM3 interacts with HuR and hnRNP A1, and with AU-RNA sequences to enhance mRNA stability and translation of AU-rich transcripts such as COX-2, VEGF and IL-8. In addition, RBM3 overexpression increases the activation of the mammalian target of rapamycin protein in a Notch dependent mechanism. We have also identified microRNAs regulated upon RBM3 overexpression, including downregulating one that inhibits its own expression. Our studies also suggest that RBM3 is regulated at the posttranslational levels of phosphorylation, ubiquitination and SUMOylation. Based on these observations, we propose three specific aims. In Aim 1, we will determine the mechanism by which RNA binding protein RBM3 regulates gene expression. Here, we will identify the RNA sequences that interact with RBM3. In addition, we will determine the sequenced in COX-2 3'UTR that are required for RBM3-mediated COX-2 mRNA stability and translation. We will also identify the role of HuR and hnRNP-A1 in the process. In Aim 2, we will determine the residues in RBM3 that undergo phosphorylation, ubiquitination and SUMOylation by mutagenesis. We will also determine the effect of the mutants on mRNA stability and translation. In Aim 3, we propose to determine the mechanisms by which RBM3 induces tumorigenesis. We will use an xenograft cancer model to determine the role of mTOR and Notch pathway in RBM3 mediated tumorigenesis. Also, the role of microRNAs in the tumorigenesis will be determined. Completion of these experiments should give us a better understanding of how the RNA binding protein RBM3 functions in normal epithelial cells, and whether changes in the RBM3 expression that is observed in tumor cells is responsible for tumor behavior. PUBLIC HEALTH RELEVANCE: Cancer is the leading cause of death in the United States. Understanding how the normal cell progresses to a cancer will aid in our developing novel therapies for this dreaded disease. We have identified a protein, RBM3 whose expression is increased in cancer cells. Overexpressing RBM3 protein causes a normal cell to become transformed into a cancer cell. Our current proposal deals with identifying mechanisms by which RBM3 expression is regulated, and also how RBM3 induces tumorigenesis. We expect that the work will lead to a better understanding of the tumorigenesis process which should subsequently lead to novel methods to stop or slow down tumorigenesis.

描述（由申请人提供）：该项目的总体目标是了解 RNA 结合蛋白 RBM3 在转录后水平上调节癌细胞中 mRNA 稳定性和翻译的基因表达的机制。我们已经发现，该蛋白质的过度表达会导致正常细胞发生表型转变，从而导致细胞在免疫功能低下的小鼠中形成肿瘤。另一方面，RBM3 表达的敲低会导致细胞因有丝分裂灾难而死亡。 RBM3 与 HuR 和 hnRNP A1 以及 AU-RNA 序列相互作用，以增强 mRNA 稳定性以及富含 AU 转录物（如 COX-2、VEGF 和 IL-8）的翻译。此外，RBM3 过表达以 Notch 依赖性机制增加哺乳动物雷帕霉素靶蛋白的激活。我们还鉴定了受 RBM3 过度表达调节的 microRNA，包括下调一种抑制其自身表达的 microRNA。我们的研究还表明，RBM3 在磷酸化、泛素化和 SUMO 化的翻译后水平受到调节。基于这些观察，我们提出了三个具体目标。在目标 1 中，我们将确定 RNA 结合蛋白 RBM3 调节基因表达的机制。在这里，我们将鉴定与 RBM3 相互作用的 RNA 序列。此外，我们将确定 RBM3 介导的 COX-2 mRNA 稳定性和翻译所需的 COX-2 3'UTR 中的测序。我们还将确定 HuR 和 hnRNP-A1 在此过程中的作用。在目标 2 中，我们将确定 RBM3 中通过诱变进行磷酸化、泛素化和 SUMO 化的残基。我们还将确定突变体对 mRNA 稳定性和翻译的影响。在目标 3 中，我们建议确定 RBM3 诱导肿瘤发生的机制。我们将使用异种移植癌症模型来确定 mTOR 和 Notch 通路在 RBM3 介导的肿瘤发生中的作用。此外，microRNA 在肿瘤发生中的作用也将被确定。这些实验的完成应该让我们更好地了解RNA结合蛋白RBM3如何在正常上皮细胞中发挥作用，以及在肿瘤细胞中观察到的RBM3表达的变化是否与肿瘤行为有关。公共卫生相关性：癌症是美国的首要死因。了解正常细胞如何发展为癌症将有助于我们开发针对这种可怕疾病的新疗法。我们已经鉴定出一种蛋白质 RBM3，其在癌细胞中的表达增加。过度表达 RBM3 蛋白会导致正常细胞转化为癌细胞。我们目前的提案涉及确定 RBM3 表达的调节机制，以及 RBM3 如何诱导肿瘤发生。我们期望这项工作将有助于更好地理解肿瘤发生过程，从而随后产生阻止或减缓肿瘤发生的新方法。