Genomic-wide Kinase Sequencing of Pediatric Brain Tumors

描述（由申请人提供）：神经外胚层起源的儿童癌症是儿童中最常见的实体肿瘤，也是目前儿童癌症相关死亡的最常见原因。该资助的目标是确定两种最常见的儿童中枢神经系统癌症的可药物靶点-恶性髓母细胞瘤和低级别星形细胞瘤。这两种肿瘤都没有表现出成人恶性星形细胞瘤所特有的明显的染色体不稳定性。这两种肿瘤通常都是野生型，因为在成人中枢神经系统癌症中最常见的肿瘤抑制基因是p53、RB和PTEN。另一方面，在这些肿瘤中，激酶活性上调与预后不良或转移潜力增加有关。本研究的假设是，髓母细胞瘤和低级别星形细胞瘤的恶性表型反映了每种肿瘤类型特有的单一蛋白激酶（或少量激酶）的功能获得突变。最近对恶性黑色素瘤遗传学的深入研究表明，这种假设是合理的。我们已经组建了一个三方团队：1)儿科肿瘤学/神经病理学，2)分子生物学/生物信息学，3)信号转导/药物发现，这使得假设可以检验，我们的目标可以实现。我们的研究计划有三个目标：(1)在三年的时间里，每年至少从15例髓母细胞瘤和15例低级别星形细胞瘤中分离DNA进行突变分析。(2)确定所有酪氨酸激酶、所有丝氨酸/苏氨酸和脂质激酶参与致癌信号通路的突变。为此，我们将对大约4000个外显子进行测序，包括酪氨酸激酶和所有致癌丝氨酸/苏氨酸激酶的整个编码序列，以及剩余丝氨酸/苏氨酸激酶和1型PI3激酶的关键部分(3)，以表征突变激酶的生化活性和生物学活性。将对突变激酶进行一系列分析测试，以确定突变是否增加了该激酶在体外或细胞中的特定活性。最后，我们将确定突变是否会增加激酶的转化潜力。这项研究将为患有脑癌的儿童带来新一代的选择性治疗方法。由于儿童癌症通常在更大的背景下具有“信息性”，因此这些药物很可能会用于更常见的成人癌症。

DESCRIPTION (provided by applicant): Pediatric cancers of neural ectodermal origin are the most common solid tumor in children and are now the most common cause of cancer-related death in children. The goal of this grant is to define drugable targets for two of the most common pediatric cancers of the central nervous system - malignant medulloblastoma and low-grade astrocytoma. Neither of these tumors exhibits gross chromosomal instability that characterizes malignant astrocytomas in adults. Both tumors are generally wild type for the tumor suppressor genes most commonly mutated in adult CNS cancers - p53, RB and PTEN. On the other hand, upregulated kinase activity has been associated with poor outcome or increased metastatic potential in these tumors. The hypothesis of this grant is that the malignant phenotype for medulloblastoma and also for low-grade astrocytoma reflects a gain-of-function mutation within a single protein kinase (or a small number of kinases) unique to each tumor type. Recent insights into the genetics of malignant melanoma suggest that this hypothesis is reasonable. We have assembled a tripartite team in 1) Pediatric Oncology/Neuro Pathology, 2) Molecular Biology/Bioinformatics and 3) Signal Transduction/Drug Discovery that makes the hypothesis testable and our goal achievable. Our study plan has three aims: (1) to isolate DNA for mutation analysis from at least 15 medulloblastoma and 15 low-grade astrocytomas a year for three years. (2) to identify mutations in all tyrosine kinases and all serine/threonine and lipid kinases involved in oncogenic signaling pathways. Towards this end, we will sequence roughly 4000 exons, covering the entire coding sequences of tyrosine kinases and of all oncogenic serine/threonine kinases as well as key portions of the remaining serine/threonine kinases and type 1 PI3 kinases, (3) to characterize the biochemical activity and biological activity of the mutant kinases. Mutant kinases will be subjected to a battery of analytical tests to see if the mutation increases the specific activity of the kinase in vitro or in cells. Finally, we will determine if the mutation increases the transformation potential of the kinase. The research will lead to a new generation of selective therapeutics for children with brain cancer. Since cancers of children are often "informative" in a larger context, it is likely that these medicines will find use for more frequent adult cancers.