Ecdysoneless, A Novel Regulator of Androgen Receptor

Ecdysoneless，一种新型雄激素受体调节剂

基本信息

批准号：
9809834
负责人：
VIMLA BAND
金额：
$ 20.69万
依托单位：
UNIVERSITY OF NEBRASKA MEDICAL CENTER
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-07-01 至 2021-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9809834
关键词：
Alternative Splicing Anchorage-Independent Growth Androgen Antagonists Androgen Receptor Area Binding Binding Proteins Biochemical Biogenesis Biological Process Cancer Burden Cancer Etiology Cancer Patient Castration Cell Line Cell Proliferation Cell Survival Cells Cessation of life Client Clinic Complex DNA Sequence Rearrangement Defect Diagnosis Drug Targeting Future Generations Genetic Transcription Glucocorticoid Receptor Homologous Gene Hormones Hyperplasia Malignant Neoplasms Malignant neoplasm of prostate Mediating Messenger RNA Molecular Molecular Chaperones Mutate New Agents Nuclear Hormone Receptors Oncogenic Outcome Pathway interactions Patients Pharmaceutical Preparations Play Prostate Prostate Cancer therapy Prostatic Intraepithelial Neoplasias Proteins RNA RNA Helicase RNA Processing RNA Splicing Receptor Gene Relapse Research Resistance Role SHFM1 gene Survival Analysis Therapeutic Tissues Translating Up-Regulation V1 Receptors Variant Xenograft procedure abiraterone androgen deprivation therapy androgen sensitive antitumor agent base castration resistant prostate cancer fly gene product hormone resistance inhibitor/antagonist insight knock-down mRNA Export mRNA Precursor men migration next generation novel overexpression paralogous gene programs prostate cancer cell prostate cancer cell line prostate cancer progression protein complex receptor upregulation recruit targeted treatment therapy resistant tumor tumor xenograft tumorigenesis

项目摘要

PROJECT SUMMARY/ABSTRACT Prostate Cancer (PCa) is the most frequently diagnosed non-cutaneous cancer in men in the US and the second most common cause of cancer deaths in men. Androgen receptor (AR) is well known driver of PCa, and androgen deprivation therapy is the initial management, but essentially all patients eventually become castration-resistant. Such patients are treated with next generation AR synthesis inhibitors (such as abiraterone) or AR antagonists (such as enzalutamide) but emergence of resistance to these agents eventually limits therapeutic choices. One of the mechanisms for such resistance is defect in AR mRNA splicing. Expression of two splice variants AR-V1, and AR-V7 is 20-fold higher in hormone resistant PCa. The proposed mechanisms include genomic rearrangement of the AR gene or upregulation of specific splicing factors. Two splicing factors, pre-mRNA processing factor 8 (PRPF8) and RNA helicase DDX39B and its paralog DDX39A seem to be involved in export and splicing of AR mRNA. Taken together a large body of evidence suggests a role of AR processing may contribute to more aggressive PCa that is hormone resistant. Therefore, identifying novel mechanisms those regulate AR processing is an important area of research to identify potential future therapy targets in PCa patients. This R21 proposal focuses on a protein ECD, a conserved homolog of the fly Ecdysoneless gene product, which we show is overexpressed in most PCa cell lines, and in Prostatic intraepithelial neoplasia (PIN) and PCa tissues, and its overexpression predicts shorter survival in patients. ECD knockdown in AR+ PCa cells reduced AR mRNA and protein levels, cell proliferation, invasion, migration and anchorage independent growth. Mechanistically, ECD interacts with components of the R2TP co-chaperone complex that plays a key role in the assembly of large protein or protein–RNA complexes. Importantly, the R2TP client complexes are involved in RNA processing. We show ECD binds to PRPF8, and DDX39A and DDX39B, proteins known to regulate mRNA export and splicing. Based on these novel findings, we hypothesize that a ternary complex of ECD, R2TP and mRNA processing proteins (PRPF8 and DDX39) promotes AR export and splicing in PCa to increase cell proliferation, cell survival and oncogenesis. Targeting this pathway can provide a potential PCa therapy strategy. Here, we will first define the composition of the ECD-containing mRNA processing machinery complexes in PCa cells using biochemical and co-localization approaches. Then we will assess the role of ECD in recruiting the mRNA processing machinery to regulate AR mRNA export and splicing in PCa cells. Finally, we will assess the potential of targeting AR mRNA processing by ECD knockdown or by use of CK2 inhibitor with or without enzalutamide. Thus, our studies will establish a new mechanistic paradigm of how PCa hyper-proliferation, cell survival and hormone resistance is driven by a novel mechanism and targeting this pathway synergizes with anti-androgen receptor agents for anti-tumor activity.

项目概要/摘要前列腺癌 (PCa) 是美国男性中最常诊断出的非皮肤癌众所周知，雄激素受体 (AR) 是导致男性癌症死亡的第二大原因。雄激素剥夺疗法是最初的治疗方法，但基本上所有患者最终都会变得此类患者接受下一代 AR 合成抑制剂（例如阿比特龙）或 AR 拮抗剂（例如恩杂鲁胺），但最终会出现对这些药物的耐药性限制治疗选择的机制之一是 AR mRNA 剪接缺陷。两种剪接变体 AR-V1 和 AR-V7 在激素抵抗性 PCa 中的表达高出 20 倍。机制包括 AR 基因的基因组重排或特定剪接因子的上调两个。剪接因子、前 mRNA 加工因子 8 (PRPF8) 和 RNA 解旋酶 DDX39B 及其旁系同源物 DDX39A 大量证据表明，AR mRNA 似乎参与了输出和剪接。 AR 处理的作用可能会导致更具侵袭性的前列腺癌，从而产生激素抵抗。调节 AR 处理的新机制是确定潜在未来的一个重要研究领域 PCa 患者的治疗目标。该 R21 提案重点关注蛋白质 ECD，它是果蝇 Ecdysoneless 基因的保守同源物我们发现该产品在大多数 PCa 细胞系和前列腺上皮内瘤变 (PIN) 中过度表达和 PCa 组织，其过度表达预示着 AR+ PCa 患者 ECD 敲低的生存期较短。细胞减少 AR mRNA 和蛋白水平，细胞增殖、侵袭、迁移和锚定无关从机制上讲，ECD 与 R2TP 共伴侣复合物的成分相互作用，发挥着关键作用。重要的是，R2TP 客户端复合物在大蛋白质或蛋白质-RNA 复合物的组装中发挥作用。我们发现 ECD 与 PRPF8、DDX39A 和 DDX39B（已知的蛋白质）结合。基于这些新的发现，我们寻求一种三元复合物。 ECD、R2TP 和 mRNA 加工蛋白（PRPF8 和 DDX39）促进 PCa 中的 AR 输出和剪接增加细胞增殖、细胞存活和肿瘤发生可以提供潜在的 PCa。在这里，我们首先定义包含 ECD 的 mRNA 加工机制的组成。然后我们将使用生化和共定位方法评估 PCa 细胞中的复合物的作用。 ECD 招募 mRNA 加工机制来调节 PCa 细胞中 AR mRNA 的输出和剪接。最后，我们将评估通过 ECD 敲低或使用 CK2 靶向 AR mRNA 加工的潜力因此，我们的研究将建立一个新的 PCa 机制范例。过度增殖、细胞存活和激素抵抗是由一种新机制驱动的，并针对这一点该途径与抗雄激素受体药物协同发挥抗肿瘤活性。