Identification of Novel Genetic Biomarkers in Brain Tumors

脑肿瘤中新型遗传生物标志物的鉴定

• 批准号: 7264544
• 负责人: JOHN K COWELL
• 金额: $ 38.93万
• 依托单位: ROSWELL PARK CANCER INSTITUTE CORP
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-20 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7264544
• 关键词: Affect; Age; Algorithms; Anchorage-Independent Growth; Astrocytes; Back; Basement membrane; Biological Assay; Biological Markers; Brain; Brain Neoplasms; Cancer Etiology; Candidate Disease Gene; Cell Line; Cells; Cessation of life; Classification; Code; Dactinomycin; Data; Development; Disease; Drug usage; Emetine; Event; Frameshift Mutation; Frequencies; Gene Expression; Genes; Genetic; Genetic Transcription; Glioma; Human; Individual; Induction of Apoptosis; Invaded; Malignant Neoplasms; Mediating; Messenger RNA; Methods; Microarray Analysis; Modeling; Molecular and Cellular Biology; Mutate; Mutation; Nonsense Codon; Nonsense-Mediated Decay; Numbers; Oligonucleotide Microarrays; PTEN gene; Pathway interactions; Patients; Pharmaceutical Preparations; Point Mutation; Protocols documentation; RB1 gene; Rate; Sampling; Series; Surveys; TP53 gene; Terminator Codon; Testing; Therapeutic Intervention; Thinking; Time; Transcript; Translation Initiation; Translations; Tumor Suppressor Genes; Tumor-Suppressor Gene Inactivation; biological adaptation to stress; cancer type; cell growth; gene discovery; improved; mRNA Decay; mRNA Transcript Degradation; migration; mutant; neoplastic cell; novel; novel therapeutics; positional cloning; prevent; promoter; research study; therapeutic target; tumor; tumorigenesis

DESCRIPTION (provided by applicant): One of the key features thought to be important in the development of brain tumors is the serial acquisition of mutations that affect critical tumor suppressor genes (TSGs). Although classical TSGs such as p53, RB1 and PTEN have been shown to be mutated in subsets of brain tumors, these genes have also been implicated in most human cancers and still relatively few brain tumor specific TSGs have been identified to date. Unfortunately, positional cloning methods and candidate gene approaches to find TSGs have been very labor intensive and unsuccessful. Clearly, an unbiased, robust and high-throughput method to detect these mutations would accelerate the discovery of these genes and promote a better understanding of brain tumorigenesis, as well as provide potential new targets for therapeutic intervention. Most TSGs are inactivated as a result of either nonsense or frameshift mutations in the coding region. Because this observation is so consistent, finding premature stop codons in candidate genes, therefore, has been the main way of identifying TSGs. Nonsense and frameshift mutations, however, frequently result in the rapid degradation of the mutant mRNA through the mechanism of nonsense mediated decay (NMD). Inhibition of NMD, e.g. by using emetine, results in increased levels of the mutant mRNA in the cell, and we have shown that these mRNAs can then be detected using gene expression arrays because they are present at higher levels than in untreated cells. Unfortunately, the drugs used to inhibit NMD also result in mRNA increases for a large number of transcripts due to stress responses. We have overcome this potential problem to a large extent by incorporating actinomycin D treatment into the protocol, which largely prevents induction of the stress response genes. We now propose to use inhibition of NMD to identify TSGs in gliomas and investigate their functional significance using a combination of cell and molecular biology approaches. These novel genes will significantly improve our understanding of the fundamental events that give rise to gliomas and through the identification of novel biomarkers may ultimately assist in the sub-classification of tumors and the identification of novel therapeutic targets.

描述（由申请人提供）：被认为在脑肿瘤发展中很重要的关键特征之一是影响关键肿瘤抑制基因（TSG）的突变的连续采集。尽管已经显示出在脑肿瘤的亚群中已证明经典的TSG（例如p53，RB1和PTEN）突变，但这些基因也与大多数人类癌症有关，并且迄今为止已经确定了相对较少的脑肿瘤特异性TSG。不幸的是，找到TSG的位置克隆方法和候选基因方法非常密集且不成功。显然，一种检测这些突变的无偏，可靠和高通量方法将加速这些基因的发现，并促进对脑肿瘤发生的更好理解，并为治疗干预提供潜在的新目标。大多数TSG由于编码区域中的废话或移码突变而被灭活。由于该观察结果是如此一致，因此在候选基因中找到过早的停止密码子是识别TSG的主要方式。然而，胡说八道和移码突变经常通过胡说八道的衰减（NMD）的机制导致突变mRNA的迅速降解。抑制NMD，例如通过使用Emetine，会导致细胞中突变mRNA的水平升高，我们已经证明可以使用基因表达阵列检测到这些mRNA，因为它们的存在于高于未处理的细胞中。不幸的是，用于抑制NMD的药物也导致由于压力反应引起的大量转录本的mRNA增加。我们通过将放线霉素D的处理纳入方案中，在很大程度上克服了这一潜在问题，这在很大程度上阻止了应力反应基因的诱导。现在，我们建议使用NMD抑制来鉴定神经胶质瘤中的TSG，并使用细胞和分子生物学方法的组合研究其功能意义。这些新型基因将显着提高我们对产生神经胶质瘤的基本事件的理解，并通过鉴定新的生物标志物最终有助于肿瘤的亚分类和新的治疗靶标的鉴定。