Splicing factors as therapeutic targets for the treatment of ovarian cancer

剪接因子作为卵巢癌治疗靶点

• 批准号: 7634178
• 负责人: WILLIAM T BECK
• 金额: $ 31.41万
• 依托单位: UNIVERSITY OF ILLINOIS AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2013-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7634178
• 关键词: Agar; Alternative Splicing; American; Apoptosis; Bioinformatics; CD44 gene; Cancer Etiology; Categories; Cell Cycle; Cell physiology; Cells; DNA; Defect; Diagnosis; Disease; Elements; Employee Strikes; Epithelial; Epithelial ovarian cancer; Epithelium; Eukaryota; Eukaryotic Cell; Event; Exhibits; Exons; Expressed Sequence Tags; FDA approved; Generations; Genes; Genomics; Goals; Homologous Gene; Human; In Vitro; Lead; MEKs; Malignant - descriptor; Malignant Neoplasms; Malignant neoplasm of ovary; Messenger RNA; Molecular; Monitor; Mus; Mutation; Neoplasm Metastasis; Neoplastic Cell Transformation; Normal tissue morphology; Oncogenes; Outcome; Ovarian; Pattern; Pharmaceutical Preparations; Play; Polypyrimidine Tract-Binding Protein; Production; Property; Protein Isoforms; Proteomics; Public Health; RNA Splicing; RNA-Binding Proteins; Ras/Raf; Reporter; Reporting; Research; Role; Signal Pathway; Small Interfering RNA; Source; Staging; Suppressor Genes; System; Testing; Therapeutic; Trans-Activators; Tumor Cell Invasion; Tumor Suppressor Genes; Validation; Variant; Woman; Work; Xenograft procedure; base; cancer therapy; cell growth; chemical synthesis; environmental change; genome wide association study; genome-wide analysis; high throughput screening; human disease; in vivo; inhibitor/antagonist; knock-down; mRNA Precursor; malignant breast neoplasm; mouse model; neoplastic cell; new therapeutic target; novel; novel therapeutic intervention; ovarian neoplasm; overexpression; public health relevance; small molecule; small molecule libraries; therapeutic target; tumor; tumor growth; tumor progression; tumorigenesis

DESCRIPTION (provided by applicant): Epithelial ovarian cancer (EOC) strikes more than 25,000 American women annually, and >50% of these women will die from their disease, especially if diagnosed, as is common, with late-stage disease. To develop new therapies for this disease, it will be necessary to better understand the molecular events that are associated with the neoplastic transformation. Alternative splicing (AS), by allowing production of multiple protein isoforms from a single gene, plays a major role in expanding proteomic complexity in metazoans and adaptations to internal and external environmental changes. In general, more genes in tumors, especially those associated with tumorigenesis, exhibit alternative splice forms compared to normal tissues. There is mounting evidence that AS is associated with and possibly involved in tumor progression and/or metastasis. At present, the mechanisms leading to splicing alterations in cancer are poorly understood, but they are likely due either to mutations in cis-elements or, more likely, changes in trans-acting factors, such as splicing factors. Indeed, several splicing factors, including PTB and SRp20, are overexpressed in tumors and one, SF2/ASF, was shown to be an oncogene. PTB and SRp20 are overexpressed in human ovarian tumors, compared to normal ovarian epithelium, where PTB is either not expressed or expressed at very low levels, and expression of these SFs is associated with malignancy of these tumors. Knockdown of PTB in ovarian tumor cells in vitro by siRNA substantially suppressed tumor cell growth, colony formation, and invasiveness and led to slower tumor growth in mice bearing ovarian tumors. Our results provide proof-of-principle that splicing factors may be a class of novel and unexplored therapeutic targets for cancer treatment, at least PTB in EOC, a disease that has a dismal outcome and for which there are no good therapeutic options, especially for advanced-stage disease. In this proposal, we focus on one splicing factor, PTB, and one tumor type, EOC, and hypothesize that PTB is a druggable therapeutic target in this disease. To test our hypothesis, we propose to develop a cell- based high-throughput screen of small molecule libraries to identify small molecules that interfere with PTB activity and then study whether these identified small molecules are able to inhibit ovarian tumor growth. To this end, we offer three specific aims: (1) Develop and optimize a proprietary cell-based reporter system to monitor the activity of PTB in the cell; (2) Develop and optimize a high throughput screen (HTS) of small molecule libraries, including those containing FDA-approved small molecules as well as extracts from natural sources or compounds generated by chemical synthesis to identify PTB inhibitors; and (3) Validation of effective small molecules on ovarian tumor cell growth in vitro and in vivo. If successful, our approach will validate PTB as a novel therapeutic target and will identify a novel class of small molecule drugs based on the manipulation of alternative splicing for the treatment of ovarian cancer, and possibly other epithelial cancers. PUBLIC HEALTH RELEVANCE: Epithelial ovarian cancer (EOC) strikes more than 25,000 American women annually, and >50% of these women will die from their disease, especially if diagnosed, as is common, with late-stage disease. If successful, the research proposed here will validate targeting of splicing factors and alternative splicing as a novel therapeutic approach to the treatment of ovarian and other cancers. At the end of the project period we would have identified small molecules leading to new drugs for the treatment of these cancers, and this will clearly have a positive impact on public health.

描述（由申请人提供）：每年有超过 25,000 名美国女性罹患上皮性卵巢癌 (EOC)，其中超过 50% 的女性将死于该病，尤其是在诊断为晚期疾病时（这很常见）。为了开发针对这种疾病的新疗法，有必要更好地了解与肿瘤转化相关的分子事件。选择性剪接（AS）允许从单个基因产生多种蛋白质亚型，在扩展后生动物蛋白质组复杂性以及适应内部和外部环境变化方面发挥着重要作用。一般来说，与正常组织相比，肿瘤中更多的基因，尤其是与肿瘤发生相关的基因，表现出选择性剪接形式。越来越多的证据表明 AS 与肿瘤进展和/或转移相关并可能参与其中。目前，导致癌症剪接改变的机制尚不清楚，但它们可能是由于顺式元件的突变，或更可能是由于剪接因子等反式作用因子的变化。事实上，包括 PTB 和 SRp20 在内的几种剪接因子在肿瘤中过度表达，其中一个 SF2/ASF 被证明是一种癌基因。与正常卵巢上皮相比，PTB 和 SRp20 在人类卵巢肿瘤中过度表达，而正常卵巢上皮中 PTB 不表达或表达水平非常低，并且这些 SF 的表达与这些肿瘤的恶性相关。体外通过 siRNA 敲低卵巢肿瘤细胞中的 PTB 显着抑制了肿瘤细胞的生长、集落形成和侵袭性，并导致荷有卵巢肿瘤的小鼠的肿瘤生长减慢。我们的结果提供了原理证明，即剪接因子可能是一类新颖且未经探索的癌症治疗靶点，至少是 EOC 中的 PTB，这种疾病的结果令人沮丧，并且没有良好的治疗选择，特别是对于晚期疾病。在本提案中，我们重点关注一种剪接因子 PTB 和一种肿瘤类型 EOC，并假设 PTB 是该疾病的药物治疗靶点。为了检验我们的假设，我们建议开发一种基于细胞的小分子库高通量筛选，以识别干扰 PTB 活性的小分子，然后研究这些识别的小分子是否能够抑制卵巢肿瘤的生长。为此，我们提出了三个具体目标：（1）开发和优化专有的基于细胞的报告系统来监测细胞中PTB的活性； (2) 开发和优化小分子库的高通量筛选（HTS），包括那些含有 FDA 批准的小分子的库以及天然来源的提取物或化学合成产生的化合物，以鉴定 PTB 抑制剂； (3)体外和体内验证小分子对卵巢肿瘤细胞生长的有效作用。如果成功，我们的方法将验证 PTB 作为一种新的治疗靶点，并将基于选择性剪接的操作确定一类新型小分子药物，用于治疗卵巢癌，可能还有其他上皮癌。公共卫生相关性：每年有超过 25,000 名美国女性罹患上皮性卵巢癌 (EOC)，其中超过 50% 的女性将死于该病，尤其是如果诊断为晚期疾病（这很常见）。如果成功，这里提出的研究将验证剪接因子和选择性剪接的靶向作为治疗卵巢癌和其他癌症的新型治疗方法。在项目期结束时，我们将鉴定出用于治疗这些癌症的新药的小分子，这显然将对公共健康产生积极影响。