Prostate-targeted CRMP4 saRNA as anti-metastatic therapy

描述（申请人提供）：本申请旨在探索抑制前列腺癌转移的新策略。该策略是使用与基因启动子互补的小双链RNA分子来增强基因转录。这些RNA分子被称为小激活RNA （saRNA）。我们将使用它们来靶向塌陷反应介质蛋白-4 （CRMP4）基因的启动子，这是最近在前列腺癌中发现的转移性抑制因子。具有高效力的候选saRNA分子将与前列腺癌特异性适配体融合，这是一种特异性结合前列腺特异性膜抗原进行递送的RNA分子。我们还将研究crmp4介导的转移抑制机制。转移是癌症死亡的主要原因，手术切缘阳性的局部晚期高危前列腺癌和高级别肿瘤常发生快速复发和全身转移。在寻找与转移性前列腺癌相关的蛋白质生物标志物时，我们发现CRMP4在前列腺癌中是一种转移抑制因子。与原发肿瘤相比，其在转移性淋巴结中的表达明显较低，在前列腺癌细胞中的过表达不仅能在体外抑制细胞的运动/侵袭，还能在动物异种移植模型中强烈抑制肿瘤转移。因此，我们假设提高CRMP4在高危前列腺癌中的表达可以抑制肿瘤转移。最近出现的证据表明，靶向基因启动子的saRNAs在转录水平上可以有效地诱导延长基因激活。一些报道已经证明了靶向肿瘤抑制基因的双链rna在体外和体内抑制肿瘤细胞生长方面的潜在用途。本应用的目的是开发和验证靶向CRMP4启动子的多种saRNAs抑制前列腺癌转移。其基本原理是基于我们最近的出版物和初步研究，以及其他小组以前的报告。我们相信，该项目的成功完成将导致前列腺癌的新疗法，甚至与其他化学试剂一起用于治疗这种威胁健康的疾病。

DESCRIPTION (provided by applicant): This application aims to explore a novel strategy in suppressing prostate cancer metastasis. The strategy is to use small double-strand RNA molecules, which are complimentary to gene promoter, to enhance gene transcription. These RNA molecules are termed as small activating RNA (saRNA). We will use them to target the promoter of collapsin response mediator protein-4 (CRMP4) gene, a recently identified metastatic suppressor in prostate cancers. The candidate saRNA molecules with high potency will be fused to a prostate cancer-specific Aptamer, a RNA molecule that specifically binds to prostate specific membrane antigen for delivery. We will also study the mechanism of CRMP4-mediated metastasis suppression. Metastasis is the major cause of cancer death and locally advanced high-risk prostate cancers with positive surgical margin and high grade tumors are often times develop rapid recurrence and systemic metastasis. In a search for protein biomarkers associated with metastatic prostate cancers, we identified CRMP4 as a metastasis suppressor in prostate cancers. Its expression is dramatically low in metastatic lymph nodes compared to primary tumors and its over-expression in prostate cancer cells not only suppressed cell motility/invasion in vitro but also strongly inhibited tumor metastasis in animal xenograft model. Thus, we hypothesized that enhancing CRMP4 expression in high-risk prostate cancers will suppress tumor metastasis. Recent emerging evidence showed that saRNAs targeting gene promoters are potent in inducing prolonged gene activation at the transcriptional level. Several reports have demonstrated the potential usage of double- stranded RNAs targeting tumor suppressor genes in inhibiting tumor cell growth in vitro and in vivo. The objective of this application is to develop and validate multiple saRNAs targeting CRMP4 promoter for suppressing metastasis of prostate cancer. The rationale is based on our recent publication and preliminary studies, as well as previous reports from other groups. We believe that its successful completion of this project would lead to a novel therapy for prostate cancers or even a cure when used with other chemo-reagents for this health-threatening disease.