Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA.
Department of Stem Cell and Regenerative Biology, Harvard University, Cambridge, MA, 02138, USA.
Nat Commun. 2024 May 21;15(1):4325. doi: 10.1038/s41467-024-48508-6.
Hematopoietic stem cell (HSC) mutations can result in clonal hematopoiesis (CH) with heterogeneous clinical outcomes. Here, we investigate how the cell state preceding Tet2 mutation impacts the pre-malignant phenotype. Using an inducible system for clonal analysis of myeloid progenitors, we find that the epigenetic features of clones at similar differentiation status are highly heterogeneous and functionally respond differently to Tet2 mutation. Cell differentiation stage also influences Tet2 mutation response indicating that the cell of origin's epigenome modulates clone-specific behaviors in CH. Molecular features associated with higher risk outcomes include Sox4 that sensitizes cells to Tet2 inactivation, inducing dedifferentiation, altered metabolism and increasing the in vivo clonal output of mutant cells, as confirmed in primary GMP and HSC models. Our findings validate the hypothesis that epigenetic features can predispose specific clones for dominance, explaining why identical genetic mutations can result in different phenotypes.
造血干细胞 (HSC) 突变可导致具有异质性临床结果的克隆性造血 (CH)。在这里,我们研究了 Tet2 突变前的细胞状态如何影响前恶性表型。使用诱导性髓系祖细胞克隆分析系统,我们发现具有相似分化状态的克隆的表观遗传特征高度异质,并且对 Tet2 突变的功能反应不同。细胞分化阶段也会影响 Tet2 突变反应,表明起源细胞的表观基因组调节 CH 中的克隆特异性行为。与更高风险结果相关的分子特征包括 Sox4,它使细胞对 Tet2 失活敏感,诱导去分化、改变代谢并增加突变细胞在体内的克隆输出,在原代 GMP 和 HSC 模型中得到证实。我们的研究结果验证了这样一种假设,即表观遗传特征可以使特定的克隆易于占据主导地位,解释了为什么相同的基因突变会导致不同的表型。