Functional Evaluation of microRNAs in Pancreatic Neoplasia

MicroRNAs(MiRNAs)是18-24个核苷酸的RNA分子，调节稳定性或翻译 互补靶mRNAs的效率。MiRNAs参与多种细胞过程 包括增殖、凋亡和分化。此外，全球异常的miRNA表达 模式似乎是人类癌细胞的一个普遍特征。我们实验室和其他实验室的工作已经 确定了miRNAs作为几个重要致癌和 肿瘤抑制通路。此外，一些miRNAs本身作为新的癌基因和肿瘤发挥作用。 抑制者。这些发现表明miRNA失调在癌症发病机制中起到了致病作用。 我们最近对胰腺癌细胞中miRNA的表达模式进行了分类，并发现了一种 与正常细胞相比，经常异常表达的miRNAs队列。基于这些 现在，我们提出了一系列实验，旨在验证以下中心假设： 受关键信号通路控制的miRNAs在 胰腺癌细胞是新的癌基因和肿瘤抑制基因。我们将检验这些假设 通过追求三个具体目标。在目标1中，我们将从功能上评估miRNA的后果 强制表达或抑制后检测肿瘤细胞表型的体外调节失调 所选miRNAs的。我们还将使用体细胞基因敲除方法来检测 特定miRNAs完全丧失功能的后果。最后，我们将启动对 通过鉴定一个重要的miRNA：靶mRNA相互作用来研究miRNAs在胰腺癌中的作用。在……里面 目的2，我们将利用我们共同开发的一种新的斑马鱼胰腺癌模型。 调查员利奇博士。通过在这个模型中专门在发育中的胰腺中表达miRNAs，我们将 能够高通量地评估miRNAs在体内胰腺癌发病机制中的作用 举止。最后，在目标3中，我们将描述一种新的小鼠模型，该模型具有丢失的 具有抗肿瘤活性的miRNA的功能，我们已经证明这一功能在胰腺中经常缺失 癌细胞。我们还将把这些小鼠培育成一个成熟的胰腺癌模型，以特别是 评估这种miRNA缺失对疾病进展的贡献。我们预计这些研究将 有助于我们理解胰腺癌的分子基础，并可能揭示 可用于治疗干预的新途径。 相关性(请参阅说明)： 胰腺导管腺癌(胰腺癌)是与癌症相关的第四大常见原因 死亡，在美国每年约有33,000人丧生。五年存活率 5%的发病率强调了当前治疗方法的无效性和这种疾病的严重程度。我们 提议研究最近描述的一类称为microRNAs的分子在胰腺癌中的作用 生物学，希望揭示新的见解，可能导致新的治疗策略。

MicroRNAs (miRNAs) are 18-24 nucleotide RNA molecules that regulate the stability or translational efficiency of complementary target mRNAs. miRNAs participate in a diverse array of cellular processes including proliferation, apoptosis, and differentiation. Moreover, globally abnormal miRNA expression patterns appear to be a ubiquitous feature of human cancer cells. Work from our laboratory and others has established that miRNAs function as critical downstream components of several important oncogenic and tumor suppressor pathways. Furthermore, some miRNAs themselves act as novel oncogenes and tumor suppressors. These findings suggest a causative role for miRNA dysregulation in cancer pathogenesis. We have recently classified miRNA expression patterns in pancreatic cancer cells and identified a cohort of miRNAs that are frequently abnormally expressed compared to normal cells. Based on these findings, we now propose a series of experiments designed to test the following central hypothesis: Key miRNAs that are controlled by critical signaling pathways and are abnormally expressed in pancreatic cancer cells act as novel oncogenes and tumor suppressors. We will test these hypotheses by pursuing three specific aims. In Aim 1, we will functionally evaluate the consequences of miRNA dysregulation in vitro by examining neoplastic cellular phenotypes following enforced expression or inhibition of selected miRNAs. We will also employ somatic cell gene knockout methodologies to examine the consequences of complete loss-of-function of specific miRNAs. Finally, we will initiate mechanistic studies of the role of miRNAs in pancreatic cancer by characterizing an important miRNA:target mRNA interaction. In Aim 2, we will take advantage a novel zebrafish model of pancreatic cancer developed by our co- investigator Dr. Leach. By expressing miRNAs in this model specifically in the developing pancreas, we will be able to assess the contribution of miRNAs to pancreatic cancer pathogenesis in vivo in a high-throughput manner. Finally, in Aim 3, we will characterize a novel mouse model that we have generated with loss of function of a miRNA with anti-tumorigenic activity that we have shown to be frequently absent in pancreatic cancer cells. We will also breed these mice to a well-established model of pancreatic cancer to specifically assess the contribution of loss of this miRNA to disease progression. We envision that these studies will contribute significantly to our understanding of the molecular basis of pancreatic cancer and may reveal novel pathways that are amenable to therapeutic intervention. RELEVANCE (See instructions): Pancreatic ductal adenocarcinoma (pancreatic cancer) is the fourth most common cause of cancer-related death, accounting for approximately 33,000 lives each year in the United States. The five year survival rate of <5% underscores the ineffectiveness of current therapies and the profound direness of this disease. We propose to study the role of a recently-described class of molecules called microRNAs in pancreatic cancer biology, with the hope of revealing new insights that could lead to novel therapeutic strategies.