EWS/FLI Regulates Transcriptional Activation in Ewing Sarcoma via Length Dependent GGAA Microsatellites

项目总结/摘要 我们在这个项目中的长期目标是阐明尤文肉瘤的分子和细胞生物学 并将这些知识转化为儿科癌症的进步。尤文肉瘤，第二个 最常见的儿童恶性骨肿瘤的特征是染色体易位T（11;22）。的 所产生的融合癌蛋白EWS/FLI是一种异常的转录因子， 在尤因细胞中转化。EWS作为一个氨基末端转录激活结构域连接到 其ETS家族成员犯罪伙伴FLI的羧基末端DNA结合域。微卫星重复 其特征在于基序GGAA用作上调的靶向的启动子内的EWS/FLI的结合位点。 尤文肉瘤的基因以前被认为是“垃圾DNA”，这些多态性微卫星作为 EWS/FLI DNA结合的反应元件，具有有趣的遗传相关性和可能的临床意义 影响尽管EWS/FLI直接或间接地激活和抑制了许多靶基因， EWS/FLI区分是否上调或下调基因表达仍不确定。因此 本文提出的实验旨在检验EWS/FLI诱导致癌转化的假设， 通过GGAA微卫星调控转录激活，GGAA微卫星的长度决定结合和效应子 功能因此，我们的目标是：1）确定GGAA微卫星在多大程度上起增强子反应的作用 2）确定GGAA基序长度在尤文肉瘤中转录激活中的作用。这 项目是儿科癌症的一个重要方法，因为它提供了一个了解致癌基因的模型。 生物标志物和治疗开发所必需的转录调节，以改善患者护理， 总体生存率。

Project Summary/Abstract Our long-term goal in this project is to elucidate the molecular and cellular biology for Ewing Sarcoma development and translate this knowledge into advances for pediatric cancer. Ewing sarcoma, the second most common pediatric malignant bone tumor, is characterized by a chromosomal translocation t(11;22). The resulting fusion oncoprotein EWS/FLI is an aberrant transcription factor necessary for oncogenic transformation in Ewing cells. EWS acts as an amino-terminal transcriptional activation domain linked to the carboxy-terminal DNA-binding domain of its ETS family member partner in crime, FLI. Microsatellite repeats characterized by the motif GGAA serve as binding sites for EWS/FLI within the promoters of upregulated target genes in Ewing Sarcoma. Previously thought of as “junk DNA,” these polymorphic microsatellites serve as response elements for EWS/FLI DNA binding with interesting genetic correlations and possible clinical implications. Though EWS/FLI both activates and represses numerous target genes directly and indirectly, how EWS/FLI distinguishes whether to up or down regulate gene expression remains undetermined. Therefore, the experiments proposed herein aim to test the hypothesis that EWS/FLI induces oncogenic transformation and regulation of transcriptional activation via GGAA microsatellites whose length dictates both binding and effector function. Thus our aims are: 1) Determine to what extent GGAA microsatellites function as enhancer response elements and 2) Determine the role of GGAA motif length in transcriptional activation in Ewing Sarcoma. This project is an important approach to pediatric cancer because it provides a model of understanding oncogenic transcriptional regulation necessary for biomarker and therapeutic development to improve patient care and overall survival.