MyoD Activity in Rhabdomyosarcomas

横纹肌肉瘤是儿童最常见的实体瘤之一，被认为是由于 肌源性前体细胞生长和分化的调控异常。尽管有这样的表达 在MyoD家族的肌源性碱性螺旋-环-螺旋蛋白中，横纹肌肉瘤细胞无法退出 脱离细胞周期，不能分化成肌肉细胞。这项研究的目的是 建议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相结合的方法，我们希望 了解如何在肌肉分化计划的多个步骤中发生调节缺陷，以及 寻找横纹肌肉瘤起源的线索。具体目标是：(一)找出妨碍 MyoD通过染色质免疫沉淀分析激活RD细胞中的一组启动子；(Ii) 利用突变和功能鉴定E2a蛋白的翻译后修饰及其功能 蛋白质-蛋白质相互作用分析；(Iii)鉴定和表征MyoD- 串联亲和纯化和串联质谱联用转录复合体。

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.