在Sonic Hedgehog中发生的生殖延长突变
Sebastian M Waszak1, Giles W Robinson2, Brian L Gudenas3
1European Molecular Biology Laboratory (EMBL), Genome Biology Unit, Heidelberg, Germany.
Nature
|April 17, 2020
概括
在ELP1基因中罕见的生殖系变异是儿童Sonic Hedgehog髓母细胞瘤的常见原因,这是一个罕见的脑癌. 这一发现突显了蛋白质平衡在癌症发展中的作用.
科学领域:
- 基因组学和分子生物学
- 儿童瘤学
- 癌症倾向综合征
背景情况:
- 虽然癌症基因组学已经确定了恶性瘤的关键驱动因素,但罕见癌症的遗传基础,特别是在儿童中,仍然很大程度上未知.
- 遗传倾向导致5-10%的儿童癌症,但合作的遗传事件尚不清楚.
- 之前的研究在5%的脑髓母细胞瘤患者中发现了致病性生殖系变异.
研究的目的:
- 确定与脑髓母细胞瘤倾向相关的新基因.
- 调查儿科髓母细胞瘤中生殖线功能丧失变异的作用,特别是Sonic Hedgehog (MB_SHH) 亚组.
- 阐明将ELP1变异与髓母细胞瘤发病的分子机制.
主要方法:
- 在儿童脑髓母细胞瘤患者中对蛋白质编码基因的全外体测序.
- 对ELP1基因中的生殖线功能丧失变体的分析.
- 对家族癌症病例进行亲子和血统分析.
- 分子亚型 (SHHα) 和体质变化的分析 (例如,PTCH1,染色体9q损失).
- 在瘤样本中研究延长器复合体功能,tRNA修饰和蛋白质平衡.
主要成果:
- 在14%的儿科MB_SHH患者中发现了ELP1的罕见生殖线功能丧失变异,使其成为这种亚型的最常见的倾向基因.
- 在儿科 MB_ SHH 中,ELP1 变异增加了遗传倾向的患病率至 40%.
- 由于9q的损失,ELP1相关的髓母细胞瘤表现出双性失活,并且经常与PTCH1的变化同时发生,这表明与SHH信号合作.
- 瘤表现出不稳定的延长器复合体,减少的tRNA修饰,以及蛋白质组不稳定的迹象,包括未折叠的蛋白质反应诱导.
结论:
- 在ELP1中发生的生殖线功能丧失变异是儿童MB_SHH的显著诱导因素,与体质SHH通路激活协同作用.
- 缺少ELP1会导致延长器综合体功能障碍,影响蛋白质平衡,并可能导致脑髓母细胞瘤的发展.
- 蛋白质组不稳定可能是儿童脑癌发病的一个关键决定因素,需要进一步研究和潜在的治疗向.
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