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，以促进新疗法的开发。新出现的证据表明，上皮细胞向间充质细胞转化（EMT）的获得，一个类似于癌症干细胞样细胞发生的过程，有助于肿瘤的侵袭性，并由microRNA（miRNAs）（如miR-200和let-7家族）的表达失调介导。miR-200表达的缺失导致Lin 28 B的过度表达，这在人PCa中是普遍的。Lin 28 B还已知阻断另一种miRNA（pre-let-7和pri-let-7）的加工，导致成熟let-7减少，从而导致Suz 12和EZH 2表达增加，这是多梳阻遏复合物2（PRC 2）的重要组分。因此，Lin 28 B的过表达和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（PC 3 PDGF-D细胞）中Lin 28 B的过表达伴随着miR-200和let-7家族的表达降低以及Suz 12和EZH 2的表达增加，这与从人PCa组织标本获得的发现一致。此外，我们发现这些标志物在非洲裔美国人和高加索裔美国人患者之间的差异表达。我们还发现，通过遗传方法或通过用我们新开发的试剂（3，4-二氟苯并姜黄素或CDF）处理细胞重新表达miR-200 b、miR-200 c和let-7下调了Lin 28 B和EZH 2的表达。基于我们的初步结果，我们假设Lin 28 B的过表达通过下调miR-200 b和miR-200 c，导致Suz 12，ZEB 1和ZEB 2的表达增加，导致PCa细胞（EMT表型细胞）获得侵袭和转移特征。我们还假设Lin 28 B的过表达抑制let-7家族的成熟，导致EZH 2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。目的-1：建立Lin 28 B调节miRNA并引起肿瘤细胞侵袭性的机制（即，增加的细胞增殖、迁移、侵袭、克隆生长和自我更新能力）。目标二：确定ADF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Lin 28 B、miR-200、let-7、Suz 12和EZH 2表达的失调所致。目标三：评估Lin 28 B、EZH 2、miR-200和let-7表达与表征非裔美国人与高加索裔美国人患者中人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组织的研究将提供对miRNA及其靶标在表征PCa侵袭性中的作用的见解，并且还将提供一种新的方法（即，CDF的使用）来设计PCa患者的靶向治疗。