Department of Haematology, University of Cambridge, NHS-BT Blood Donor Centre, Cambridge, United Kingdom.
Department of Haematology, University of Cambridge, Cambridge Institute for Medical Research, Cambridge, United Kingdom.
Elife. 2020 Jan 27;9:e51754. doi: 10.7554/eLife.51754.
Acute Myeloid Leukemia (AML) is an aggressive hematological malignancy with abnormal progenitor self-renewal and defective white blood cell differentiation. Its pathogenesis comprises subversion of transcriptional regulation, through mutation and by hijacking normal chromatin regulation. Kat2a is a histone acetyltransferase central to promoter activity, that we recently associated with stability of pluripotency networks, and identified as a genetic vulnerability in AML. Through combined chromatin profiling and single-cell transcriptomics of a conditional knockout mouse, we demonstrate that Kat2a contributes to leukemia propagation through preservation of leukemia stem-like cells. Kat2a loss impacts transcription factor binding and reduces transcriptional burst frequency in a subset of gene promoters, generating enhanced variability of transcript levels. Destabilization of target programs shifts leukemia cell fate out of self-renewal into differentiation. We propose that control of transcriptional variability is central to leukemia stem-like cell propagation, and establish a paradigm exploitable in different tumors and distinct stages of cancer evolution.
急性髓系白血病(AML)是一种侵袭性血液系统恶性肿瘤,具有异常祖细胞自我更新和白细胞分化缺陷。其发病机制包括转录调控的颠覆,通过突变和劫持正常染色质调控。Kat2a 是启动子活性的组蛋白乙酰转移酶的核心,我们最近将其与多能性网络的稳定性相关联,并将其鉴定为 AML 的遗传脆弱性。通过对条件性敲除小鼠的联合染色质分析和单细胞转录组学分析,我们证明 Kat2a 通过维持白血病干细胞样细胞促进白血病的增殖。Kat2a 的缺失会影响转录因子结合,并降低基因启动子亚集中的转录爆发频率,从而增加转录本水平的变异性。靶程序的不稳定性将白血病细胞命运从自我更新转变为分化。我们提出,转录变异性的控制是白血病干细胞样细胞增殖的核心,并为不同肿瘤和癌症进化的不同阶段建立了一个可利用的范例。