Validation of microRNA Targets in Glioma

描述(申请人提供)：神经胶质起源的恶性脑瘤在今天仍然是一个严重的临床和科学问题。恶性程度最高的胶质瘤--胶质母细胞瘤--患者的平均生存时间不到一年。与其他癌症一样，胶质瘤是由细胞增殖、分化、迁移和死亡失调引起的疾病。然而，导致这些关键过程失调的分子事件还没有被很好地理解。如何在肿瘤形成过程中控制基因表达将是了解这些肿瘤生物学的关键问题。 最近，一类新的小分子调控分子microRNA(MiRNA)被认为参与了多种癌症中基因表达的转录后调控。许多miRNAs在胶质瘤中异常表达，其中一些可能调节重要的癌基因和抑癌基因的表达。这项建议的总体目标是验证miRNAs在人脑胶质瘤形成中的功能作用，并阐明介导这些miRNAs功能的细胞内信号通路。为了实现这一目标，将在胶质瘤细胞中抑制选定的致癌miRNAs，并检测这些操作对胶质瘤生长的体外和体内参数的影响。由于miRNA抑制可能会产生各种非靶标效应，因此特定的目标1将涉及对目标miRNAs的高度特异性寡核苷酸抑制剂的验证。使用这些特定的工具，我们将验证在胶质瘤细胞中介导miRNA功能的关键mRNA靶点。在特定的目标2中，我们将在体外确定miRNAs对胶质瘤细胞存活、增殖和凋亡的影响。在具体目标3中，我们将利用体外和体内的方法，进一步确定miRNAs和最有效的miRNA组合对动物模型中脑胶质瘤生长和侵袭的影响。这项拟议的工作有望对胶质瘤的生物学以及更广泛的癌症中的基因表达产生重要的新见解，并可能验证一类用于胶质瘤治疗的新型分子靶点。 与公共卫生相关：尽管接受了非常积极的治疗，但在过去的25年里，被诊断为恶性脑瘤和胶质母细胞瘤的患者的存活率只有轻微的变化。迫切需要新的分子靶点、概念和方法来治疗这种毁灭性的疾病。最近发现的被称为microRNAs的小调节RNA分子，调节与大脑中肿瘤形成有关的分子事件。这项关于microRNA的拟议工作有望促进我们对脑瘤的理解，并可能为新的治疗方法打开大门。

DESCRIPTION (provided by applicant): Malignant brain tumors of glial origin remain today as a serious clinical and scientific problem as ever. Patients with the most malignant glioma, glioblastoma, have an average survival time of less than one year. Like other cancers, gliomas are diseases caused by dysregulated cell proliferation, differentiation, migration and death. However, molecular events that lead to dysregulation of these key processes are not well understood. How gene expression is controlled in tumor formation will be a critical issue in understanding the biology of these tumors. Recently, a novel class of small regulatory molecules, microRNA (miRNA), has been implicated in post-transcriptional regulation of gene expression in a wide range of cancers. A number of miRNAs are aberrantly expressed in gliomas, and some of them may regulate expression of important oncogenes and tumor suppressors. The overall goal of this proposal is to validate miRNAs playing a functional role in human glioma formation and to elucidate intracellular signaling pathways that mediate functions of these miRNAs. To achieve this goal, selected oncogenic miRNAs will be inhibited in glioma cells and effects of these manipulations on in vitro and in vivo parameters of glioma growth will be examined. Since miRNA inhibition may potentially produce various off-target effects, Specific Aim 1 will involve validation of highly specific oligonucleotide inhibitors for the miRNAs of interest. Using these specific tools, we will validate key mRNA targets that mediate miRNA functions in glioma cells. In Specific Aim 2 we will determine effects of the miRNAs on glioma cell viability, proliferation, and apoptosis in vitro. In Specific Aim 3, using ex vivo and in vivo approaches, we will further determine effects of the miRNAs and most potent miRNA combinations on growth and invasion of intracranial glioma tumors in animal models. The proposed work promises to yield significant new insights into the biology of glioma, and more generally - gene expression in cancer, and may validate a novel class of molecular targets for glioma therapy. PUBLIC HEALTH RELEVANCE: Despite very aggressive treatments, survival for patients diagnosed with malignant brain tumor, glioblastoma, has only marginally changed over the past 25 years. There is a critical need for new molecular targets, concepts and approaches to treat this devastating disease. Recently discovered small regulatory RNA molecules, known as microRNAs, regulate molecular events involved in tumor formation in the brain. The proposed work on microRNAs holds promises to advance our understanding of brain tumors and may open the door to novel treatments.