Validation of microRNA Targets in Glioma

描述（由申请人提供）：胶质源性恶性脑肿瘤今天仍然是一个严重的临床和科学问题。恶性程度最高的神经胶质瘤（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，神经胶质瘤是由失调的细胞增殖、分化、迁移和死亡引起的疾病。然而，导致这些关键过程失调的分子事件还没有得到很好的理解。如何在肿瘤形成中控制基因表达将是理解这些肿瘤生物学的关键问题。 最近，一类新的小调控分子，microRNA（miRNA），已涉及在广泛的癌症中的基因表达的转录后调控。许多miRNAs在胶质瘤中异常表达，其中一些可能调控重要癌基因和肿瘤抑制因子的表达。该提案的总体目标是验证miRNAs在人脑胶质瘤形成中发挥的功能作用，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miRNA，并检查这些操作对胶质瘤生长的体外和体内参数的影响。由于miRNA抑制可能潜在地产生各种脱靶效应，因此特异性目标1将涉及针对感兴趣的miRNA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。在具体目标2中，我们将确定miRNA对胶质瘤细胞活力，增殖和凋亡的影响。在具体目标3中，使用离体和体内方法，我们将进一步确定miRNA和最有效的miRNA组合对动物模型中颅内胶质瘤肿瘤生长和侵袭的影响。拟议的工作有望产生重大的新见解，神经胶质瘤的生物学，更普遍的-基因表达在癌症中，并可能验证一类新的分子靶点神经胶质瘤治疗。 公共卫生相关性：尽管有非常积极的治疗，但在过去的25年里，恶性脑肿瘤（胶质母细胞瘤）患者的生存率只有轻微的变化。迫切需要新的分子靶标、概念和方法来治疗这种毁灭性疾病。最近发现的小调节RNA分子，称为microRNA，调节参与大脑肿瘤形成的分子事件。关于microRNA的拟议工作有望促进我们对脑肿瘤的理解，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.