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: 8520266
• 负责人: FAZLUL H. SARKAR
• 金额: $ 29.65万
• 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 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8520266
• 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; Genetic; 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; epithelial to mesenchymal transition; 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; 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）相关的死亡是由castrate抗性前列腺癌（CRPC）的出现以及随后的转移引起的，这表明需要对肿瘤侵袭性有更好的理解，以便推动新疗法的发展。新兴的证据表明，上皮到间质转变（EMT）的获取类似于癌症干细胞的发生，有助于肿瘤侵袭性，并由microRNAS（miRNA）（例如miRNA）（例如miRNAS）（例如miRNAS）（例如miRNAS）和Let-7家族介导。 miR-200表达的损失导致Lin28b的过表达，这在人PCA中很普遍。 LIN28B也已知可以阻止另一个miRNA的加工（PE-LET-7和PRI-LET-7），从而导致成熟的Let-7降低，从而导致SUZ12和EZH2表达增加，这是Polycomb抑制性复合物2的重要组成部分（PRC2）。因此，LIN28B的过度表达以及miR-200和Let-7的丢失似乎是PCA侵略性的原因。我们发现，LIN28B与EMT表型（PC3 PDGF- D细胞）在PDGF-D过表达PCA细胞中的过表达，而MiR-200和Let-7家族的表达降低，SUZ12和EZH2的表达降低，这与从人类PCA Telffer中获得的发现是一致的。此外，我们发现非裔美国人和高加索裔美国人患者之间这些标记物的差异表达。我们还发现，miR-200b，miR-200C和Let-7的重新表达是通过遗传方法或通过我们新发育的剂（3,4-二氟贝曲霉或CDF）处理细胞的表达，以lin28b和ezh2的表达下调。基于我们的初步结果，我们假设LIN28B的过表达导致通过MIR-200B和MIR-200C的下调PCA细胞（EMT-型细胞）在PCA细胞（EMT-Phenotype细胞）中的侵入性和转移性特征的获取，从而导致SUZ12，ZEB1和ZEB2的表达增加。我们还假设LIN28B的过表达抑制了Let-7家族的成熟，从而导致EZH2的表达增加，并且可以通过用CDF处理细胞来减弱这些过程。我们将以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的抑制是否是由于Lin28b，MiR-200，Let-7，Suz12和EZH2表达在体外和动物模型中的表达是否导致。 AIM-3：与高加索裔美国人患者相比，非裔美国人PCA组织标本中人类PCA组织标本中的肿瘤侵袭性的LIN28B，EZH2，MIR-200和LET-7表达的相关性。我们的临床前机理和基于PCA的基于PCA的研究将提供有关miRNA及其在表征PCA侵略性方面的作用的见解，还将提供一种新颖的方法（即使用CDF）在为PCA患者设计有针对性的治疗方面。