Modeling E2F3 isoform specificity in prostate cancer

前列腺癌中 E2F3 异构体特异性建模

• 批准号: 8045264
• 负责人: MARIA MUDRYJ
• 金额: --
• 依托单位: VA NORTHERN CALIFORNIA HEALTH CARE SYS
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-10-01 至 2014-09-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8045264
• 关键词: Ablation; Adhesions; Age; Androgens; Apoptosis; Benign; Biological Assay; Blood specimen; Cancer Etiology; Cancer Model; Castration; Cell Adhesion; Cell Line; Cell physiology; Cell-Cell Adhesion; Cells; Clinical; Data; Development; Diagnosis; Disease; Disease Progression; E2F3 protein; Etiology; Family member; Genes; Genetically Engineered Mouse; Gleason Grade for Prostate Cancer; Healthcare; Hormonal; Human; Hypertrophy; Immunoblot Analysis; In Situ Hybridization; In Vitro; Laboratories; Link; Malignant neoplasm of prostate; Mediating; Methodology; MicroRNAs; Modeling; Monitor; Morbidity - disease rate; Multivariate Analysis; Mus; Outcome; PSA level; Pathway interactions; Patients; Phenotype; Play; Process; Prostate; Prostatic Neoplasms; Protein Isoforms; Proteins; Publishing; Radical Prostatectomy; Regulation; Relapse; Reporter; Reporting; Resistance; Reverse Transcriptase Polymerase Chain Reaction; Role; SV40 T Antigens; Sampling; Signal Pathway; Small Interfering RNA; Specificity; Staging; Survival Rate; Therapeutic; Tissues; Tumor Suppressor Proteins; Tumor Tissue; Tumor-Derived; Veterans; Western Blotting; agent orange; base; c-myc Genes; cancer cell; cancer diagnosis; cell motility; cell transformation; chromatin immunoprecipitation; defined contribution; human DICER1 protein; immortalized cell; improved; male; mortality; mouse model; new therapeutic target; nuclease; overexpression; prevent; promoter; response; therapeutic target; tumor; tumor progression; tumorigenesis

DESCRIPTION (provided by applicant): Prostate cancer is a major cause of cancer morbidity and mortality of older VA patients. Androgen ablation therapy is initially successful, but relapses occur due to the development of castration resistant prostate cancer (CRPC). Currently treatment options for CRPC are limited, indicating a need for the identification of new therapeutic targets. Studies indicate that the E2F3 transcription factor is overexpressed in prostate cancers, and overexpression correlates with a poor clinical outcome. The E2F3 locus encodes two isoforms, E2F3a and E2F3b, but, due to technical reasons, previously reported studies only examined E2F3a expression. Preliminary data from our laboratory indicates that prostate tumor derived cell lines express higher levels of E2F3a and E2F3b than non-transformed prostate cells. A comparison of human prostate tumors and control benign prostate hypertrophy samples indicates some tumors have elevated E2F3a and b. siRNA mediated decrease of E2F3b in tumor derived cells has a more severe effect on cell physiology than a decrease of E2F3a, indicating that E2F3b has a unique role in tumorigenesis. Additionally we found that E2F3b regulates the expression of the microRNA processing nuclease Dicer. Previous studies reported that Dicer expression is elevated in advanced and metastatic prostate tumors. Our studies link the E2F/RB signaling pathway to the miRNA machinery. We hypothesize that E2F3b promotes prostate tumorigenesis by increasing proliferation, and altering adhesion and motility. The proposed studies have three specific aims. In Specific Aim 1 we will define the role of E2F3b in proliferation, cell adhesion and motility using prostate tumor-derived cell culture lines. Additionally, the role of E2F3b in the regulation of the endogenous Dicer gene will be characterized, and lastly, the role of E2F3 isoforms in regulating miRNA clusters will be examined. Studies proposed in Specific Aim 2 will focus on genetically engineered mouse models. The expression of the E2F3 isoforms and of Dicer will be studied in three models of prostate cancer: 1) SV40 T-Antigen, 2) high levels of c-myc, and 3) Nkx3.1 and Pten tumor suppressor hemizygosity. These models mimic pathway alteration identified in human tumors. The studies in Specific Aim 3 will characterize E2F3 isoform expression in human tumor samples, in surrounding tissue and BPH control samples using immunohistochemical, Western immunoblot, and quantitative RT-PCR analysis of micro-dissected tumor tissue. Complementary studies will characterize the expression of Dicer in tumor and non-tumor tissue. Lastly, the expression of the E2F3 isoforms and Dicer will be correlated with disease progression and response to therapy. The studies will determine if E2F3b or E2F3b targets are potential therapeutic targets to halt prostate tumor progression. PUBLIC HEALTH RELEVANCE: Prostate cancer, the most common cancer diagnosed in the VA healthcare has few treatment options and currently it is difficult to predict which treatments will be effective. Recent studies indicate that veterans that were exposed to Agent Orange have 48% higher rates of prostate cancer, an earlier age of diagnosis and accelerated the disease process. The studies proposed will analyze the E2F3a and b proteins, which our studies indicate are important in tumor development.

描述（由申请人提供）： 前列腺癌是老年VA患者癌症发病率和死亡率的主要原因。雄激素消融治疗最初是成功的，但由于去势抵抗性前列腺癌（CRPC）的发展而复发。目前CRPC的治疗选择有限，表明需要确定新的治疗靶点。研究表明，E2 F3转录因子在前列腺癌中过表达，并且过表达与不良临床结果相关。E2 F3基因座编码两种亚型E2 F3 a和E2 F3 b，但由于技术原因，先前报道的研究仅检测了E2 F3 a的表达。来自我们实验室的初步数据表明，前列腺肿瘤衍生的细胞系比非转化的前列腺细胞表达更高水平的E2 F3 a和E2 F3 b。人前列腺肿瘤和对照良性前列腺肥大样品的比较表明一些肿瘤具有升高的E2 F3 a和B。siRNA介导的肿瘤衍生细胞中E2 F3 b的减少对细胞生理学的影响比E2 F3 a的减少更严重，表明E2 F3 b在肿瘤发生中具有独特的作用。此外，我们发现E2 F3 b调节microRNA加工核酸酶Dicer的表达。先前的研究报道，Dicer表达在晚期和转移性前列腺肿瘤中升高。我们的研究将E2 F/RB信号通路与miRNA机制联系起来。我们推测E2 F3 b通过增加增殖、改变粘附和运动性来促进前列腺肿瘤发生。拟议的研究有三个具体目标。在具体目标1中，我们将使用前列腺肿瘤衍生的细胞培养系来定义E2 F3 b在增殖、细胞粘附和运动中的作用。此外，E2 F3 b在调节内源性Dicer基因中的作用将被表征，最后，E2 F3同种型在调节miRNA簇中的作用将被检查。具体目标2中提出的研究将集中在基因工程小鼠模型上。将在三种前列腺癌模型中研究E2 F3亚型和Dicer的表达：1）SV 40 T抗原，2）高水平的c-myc，和3）Nkx3.1和Pten肿瘤抑制因子半合子。这些模型模拟在人类肿瘤中鉴定的途径改变。Specific Aim 3中的研究将使用显微切割肿瘤组织的免疫组化、Western免疫印迹和定量RT-PCR分析来表征人肿瘤样本、周围组织和BPH对照样本中的E2 F3亚型表达。补充研究将表征Dicer在肿瘤和非肿瘤组织中的表达。最后，E2 F3亚型和Dicer的表达将与疾病进展和对治疗的反应相关。这些研究将确定E2 F3 b或E2 F3 b靶标是否是阻止前列腺肿瘤进展的潜在治疗靶标。 公共卫生相关性： 前列腺癌是VA医疗保健中诊断出的最常见的癌症，治疗选择很少，目前很难预测哪种治疗方法有效。最近的研究表明，暴露于橙子剂的退伍军人患前列腺癌的几率高出48%，诊断年龄更早，并加速了疾病的进程。本研究将分析E2 F3 a和B蛋白，我们的研究表明这两种蛋白在肿瘤发展中很重要。