揭示黑色素瘤发病的最小途径
bioRxiv : the preprint server for biology
|December 18, 2023
概括
单独激活BRAF可以在小鼠中启动缓慢生长的黑色素瘤,而不依赖于新的突变. 这表明一种表观遗传过渡涉及前恶性"低颜色,神经和细胞外基质签名" (LNM) 细胞.
科学领域:
- 在瘤学瘤学.
- 皮肤病学 皮肤病学
- 分子生物学分子生物学
背景情况:
- 皮肤黑色素瘤表现出显著的临床和组织学异质性.
- 常见的遗传改变包括激活BRAF或NRAS的突变和瘤抑制基因的丧失.
- 现有的与BRAF激活和瘤抑制剂损失的小鼠模型产生快速生长的,有色素的瘤.
研究的目的:
- 为了研究小鼠中缓慢生长的低颜色黑色素瘤的发展,单独使用BRAF激活或与异性PTEN损失相结合.
- 为了确定这些独特的瘤类型背后的细胞起源和分子机制.
- 探索特定细胞群在黑色素瘤发育和耐药性中的作用.
主要方法:
- 在白化背景下利用了具有特定突变 (BRAF激活,PTEN异性损失) 的基因工程小鼠模型.
- 分析了瘤生长动力学,色素水平和出现时间.
- 进行单细胞转录组分析以识别不同的细胞群和它们的基因表达特征.
- 研究了通过移植识别的细胞类型的前恶性潜力和持久性.
主要成果:
- 仅仅在白色背景上激活BRAF可以诱导罕见的,生长缓慢的低颜色瘤,这表明表观遗传过渡而不是新突变.
- 单细胞转录组学揭示了一种异质的瘤组成,包括一种称为LNM (低颜色,神经和细胞外基质签名) 细胞的小细胞类型.
- LNM细胞表现的基因表达类似于在侵袭性黑色素瘤中发现的神经状细胞,并且似乎在正常皮肤中预先存在.
- 通过BRAF激活,LNM细胞被扩大,可以过渡到恶性细胞,并通过移植持续存在,表明前恶性作用.
结论:
- 激活BRAF可以通过涉及LNM细胞的表观遗传机制启动黑色素瘤的发展,特别是在特定的遗传背景中.
- LNM细胞代表了恶性前状态,可以导致缓慢生长的黑色素瘤.
- 瘤细胞也可能在黑色素瘤药物耐药性的发展中作为中间体发挥关键作用.
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