MyoD Activity in Rhabdomyosarcomas

横纹肌肉瘤是儿童期最常见的实体瘤之一，据信是由于 成肌前体细胞生长和分化的调节异常。尽管有这样的说法 在MyoD家族的肌源性碱性螺旋环螺旋蛋白中，横纹肌肉瘤细胞不能从细胞中撤出， 从细胞周期中分离出来，不能分化成肌肉细胞。本研究的目的 我们的建议是研究阻止人类胚胎分化的分子机制， 横纹肌肉瘤（RD）细胞。通过应用分子和生物化学方法，我们希望 了解肌肉分化程序的多个步骤中如何发生调节缺陷， 找到横纹肌肉瘤起源的线索具体目标是：（一）确定预防因素 MyoD使用染色质免疫沉淀测定激活RD细胞中的启动子子集;（II） 使用诱变表征E2 A蛋白上的翻译后修饰及其功能性， 蛋白质-蛋白质相互作用测定;（III）鉴定和表征MyoD中的RD特异性改变- 通过串联亲和纯化和串联质谱法测定相关的转录复合物。

Rhabdomyosarcoma, one of the most common solid tumors of childhood, is believed to arise as a result of a regulatory abnormality of the growth and differentiation of myogenic precursor cells. Despite the expression of myogenic basic-helix-loop-helix proteins of the MyoD family, rhabdomyosarcoma cells fail to withdraw from the cell cycle and are unable to differentiate into muscle cells. The OBJECTIVE of this research proposal is to investigate the molecular mechanisms that prevent differentiation in human embryonal rhabdomyosarcoma (RD) cells. By applying combined molecular and biochemical approaches, we hope to understand how regulatory defects could occur at multiple steps of the muscle differentiation program and find clues to the origin of rhabdomyosarcomas. The SPECIFIC AIMS are: (I) Identify the factors that prevent MyoD from activating a subset of promoters in RD cells using chromatin immuno-precipitation assays; (II) Characterize post-translational modifications and their functionality on E2A proteins using mutagenesis and protein-protein interaction assays; (III) Identify and characterize RD-specific alterations in the MyoD- associated transcriptional complex by Tandem Affinity Purification and tandem mass spectrometry.