Mechanistic Role of miRNAs and Their Targets in Prostate Cancer Aggressiveness

miRNA 及其靶标在前列腺癌侵袭性中的机制作用

• 批准号: 8890800
• 负责人: FAZLUL H. SARKAR
• 金额: $ 31.54万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-01 至 2016-01-27
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8890800
• 关键词: Advanced Development; African American; Algorithms; Androgens; Animal Model; Attenuated; Binding Sites; Biological; Biological Availability; Biological Markers; Cancer Etiology; Cancer Patient; Cause of Death; Cell Proliferation; Cells; Cessation of life; Characteristics; Clinical Research; Complex; Curcumin; D Cells; Disease; Dose; Down-Regulation; EZH2 gene; Family; Formalin; Gene Targeting; Growth; Human; In Vitro; Institution; Investigation; LNCaP; Malignant Neoplasms; Malignant neoplasm of prostate; Mediating; MicroRNAs; Molecular Profiling; Neoplasm Metastasis; Normal tissue morphology; PC3 cell line; Paraffin Embedding; Patients; Phenotype; Platelet-Derived Growth Factor; Play; Point Mutation; Polycomb; Procedures; Process; Prostate; Publications; Race; Research; Resistance; Reverse Transcriptase Polymerase Chain Reaction; Role; Specimen; Stem cells; Testing; Therapeutic; Time; Tissue Microarray; Tissues; United States; analog; base; caucasian American; cell growth; cellular engineering; clinically relevant; deprivation; design; differential expression; epithelial to mesenchymal transition; genetic approach; in vivo; in vivo Model; insight; men; migration; mutant; neoplastic cell; novel; novel strategies; pre-clinical; pre-miRNA; prostate cancer cell; protein expression; self-renewal; stem; stemness; targeted treatment; tumor

DESCRIPTION (provided by applicant): Prostate cancer (PCa)-related deaths are caused by the emergence of castrate-resistant prostate cancer (CRPC) and subsequent metastasis, suggesting the need for better mechanistic understanding of tumor aggressiveness in order to advance the development of novel therapies. Emerging evidence suggests that acquisition of the epithelial-to-mesenchymal transition (EMT), a process that resembles the genesis of cancer stem-like cells, contributes to tumor aggressiveness and is mediated by deregulated expression of microRNAs (miRNAs), such as miR-200 and let-7 family. Loss of miR-200 expression results in the over-expression of Lin28B, which is prevalent in human PCa. Lin28B is also known to block the processing of another miRNA (pre-let-7 and pri-let-7), resulting in decreased mature let-7, thereby leads to increased Suz12 and EZH2 expression, which are important components of the polycomb repressive complex 2 (PRC2). Thus, over- expression of Lin28B and loss of miR-200 and let-7 appear to be responsible for PCa aggressiveness. We found over-expression of Lin28B in PDGF-D-over-expressing PCa cells with the EMT phenotype (PC3 PDGF- D cells) concomitant with decreased expression of miR-200 and let-7 family and increased expression of Suz12 and EZH2, which is consistent with findings obtained from human PCa tissue specimens. Moreover, we found differential expression of these markers between African-American and Caucasian-American patients. We also found that the re-expression of miR-200b, miR-200c, and let-7 either by a genetic approach or by treating cells with our newly developed agent (3,4-difluorobenzo-curcumin or CDF) down-regulated the expression of Lin28B and EZH2. Based on our preliminary results, we hypothesize that over-expression of Lin28B leads to the acquisition of invasive and metastatic characteristics in PCa cells (EMT-phenotype cells) via down-regulation of miR-200b and miR-200c, resulting in increased expression of Suz12, ZEB1, and ZEB2. We also hypothesize that over-expression of Lin28B represses the maturation of let-7 family, leading to increased expression of EZH2, and these processes can be attenuated by treatment of cells with CDF. We will test our hypotheses by three specific aims. Aim-1: Establish the mechanism(s) by which Lin28B regulates miRNAs and causes tumor cell aggressiveness (i.e., increased cell proliferation, migration, invasion, clonogenic growth, and self-renewal capacity). Aim 2: Determine whether CDF-mediated inhibition of tumor cell growth is due to deregulation of Lin28B, miR-200, let-7, Suz12, and EZH2 expression both in vitro and in an animal model in vivo. Aim-3: Assess the relevance of Lin28B, EZH2, miR-200, and let-7 expression for characterizing tumor aggressiveness in human PCa tissue specimens in African-American compared to Caucasian-American patients. Our pre-clinical mechanistic and PCa-tissue-based research will provide insights into the roles of miRNAs and their targets in characterizing PCa aggressiveness, and will also provide a novel approach (i.e., use of CDF) toward designing targeted therapy for PCa patients.

描述（由申请人提供）：前列腺癌（PCa）相关死亡是由去势抵抗性前列腺癌（CRPC）的出现和随后的转移引起的，这表明需要更好地了解肿瘤侵袭性的机制，以促进癌症的发展新疗法。新的证据表明，上皮-间质转化 (EMT) 的获得（这一过程类似于癌症干细胞样细胞的发生）有助于肿瘤的侵袭性，并且是由 microRNA (miRNA) 的表达失调介导的，例如 miR- 200和let-7家庭。 miR-200 表达缺失会导致 Lin28B 过度表达，而 Lin28B 在人类 PCa 中普遍存在。 Lin28B 还可以阻断另一种 miRNA（pre-let-7 和 pri-let-7）的加工，导致成熟 let-7 减少，从而导致 Suz12 和 EZH2 表达增加，这是多梳抑制的重要组成部分复合物 2 (PRC2)。因此，Lin28B 的过度表达以及 miR-200 和 let-7 的缺失似乎是 PCa 侵袭性的原因。我们发现，在具有 EMT 表型的 PDGF-D 过表达 PCa 细胞（PC3 PDGF-D 细胞）中，Lin28B 过表达，同时伴随 miR-200 和 let-7 家族表达降低以及 Suz12 和 EZH2 表达增加，这与从人类 PCa 组织标本中获得的结果一致。此外，我们发现这些标记物在非裔美国人和白人美国患者之间存在差异表达。我们还发现，通过遗传方法或用我们新开发的药物（3,4-二氟苯并姜黄素或 CDF）处理细胞，miR-200b、miR-200c 和 let-7 的重新表达下调了Lin28B 和 EZH2 的表达。根据我们的初步结果，我们假设 Lin28B 的过度表达通过 miR-200b 和 miR-200c 的下调导致 PCa 细胞（EMT 表型细胞）获得侵袭和转移特征，从而导致 miR-200b 和 miR-200c 的表达增加。 Suz12、ZEB1 和 ZEB2。我们还假设 Lin28B 的过度表达会抑制 let-7 家族的成熟，导致 EZH2 表达增加，并且这些过程可以通过用 CDF 处理细胞来减弱。我们将通过三个具体目标来检验我们的假设。 Aim-1：建立 Lin28B 调节 miRNA 并引起肿瘤细胞侵袭性的机制（即增加细胞增殖、迁移、侵袭、克隆生长和自我更新能力）。目标 2：确定 CDF 介导的肿瘤细胞生长抑制是否是由于体外和体内动物模型中 Lin28B、miR-200、let-7、Suz12 和 EZH2 表达失调所致。 Aim-3：评估非裔美国人与白种人美国患者中 Lin28B、EZH2、miR-200 和 let-7 表达与表征人类 PCa 组织标本中肿瘤侵袭性的相关性。我们的临床前机制和基于 PCa 组织的研究将深入了解 miRNA 及其靶标在表征 PCa 侵袭性方面的作用，并且还将提供一种为 PCa 患者设计靶向治疗的新方法（即使用 CDF）。