Pediatric acute myeloid leukemia frequently harbors fusion oncogenes associated with poor prognosis, including KMT2A, NUP98, and GLIS2 rearrangements. Although murine models have demonstrated their leukemogenic activities, the steps from a normal human cell to leukemic blasts remain unclear. Here, we precisely reproduced the inversion of chromosome 16 resulting in the ETO2::GLIS2 fusion in human induced pluripotent stem cells (iPSCs). iPSC-derived ETO2::GLIS2-expressing hematopoietic cells showed differentiation alterations in vitro and efficiently induced in vivo development of leukemia that closely phenocopied human acute megakaryoblastic leukemia (AMKL), reflected by flow cytometry and single-cell transcriptomes. Comparison of iPS-derived cells with patient-derived cells revealed altered chromatin accessibility at early and later bona fide leukemia stages, with aberrantly higher accessibility and expression of the osteogenic homeobox factor DLX3 that preceded increased accessibility to ETS factors. DLX3 overexpression in normal CD34+ cells increased accessibility to ETS motifs and reduced accessibility to GATA motifs. A DLX3 transcriptional module was globally enriched in both ETO2::GLIS2 AMKL and some aggressive pediatric osteosarcoma. Importantly, DLX3 knockout abrogated leukemia initiation in this ETO2::GLIS2 iPSC model. Collectively, the characterization of a novel human iPSC-derived AMKL model revealed that hijacking of the osteogenic homeobox transcription factor DLX3 is an essential early step in chromatin changes and leukemogenesis driven by the ETO2::GLIS2 fusion oncogene.

中文翻译：

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在小儿白血病开始的基因组编辑人类 iPSC 模型中揭示 ETO2：：GLIS2 进行性染色质重连


小儿急性髓系白血病通常含有与预后不良相关的融合癌基因，包括 KMT2A、NUP98 和 GLIS2 重排。尽管小鼠模型已证明其致白血病活性，但从正常人类细胞到白血病原始细胞的步骤仍不清楚。在这里，我们精确再现了 16 号染色体的倒位，导致人诱导多能干细胞 （iPSC） 中的 ETO2：：GLIS2 融合。iPSC 衍生的 ETO2：：GLIS2 表达造血细胞在体外显示出分化改变，并在体内有效诱导白血病的发展，这与人急性巨核细胞白血病 （AMKL） 的表型复制非常接近，通过流式细胞术和单细胞转录组反映。iPS 来源细胞与患者来源细胞的比较显示，在真正的白血病早期和晚期，染色质可及性发生了变化，成骨同源框因子 DLX3 的可及性和表达异常较高，而 ETS 因子的可及性增加。在正常 CD34 + 细胞中过表达 DLX3 增加了对 ETS 基序的可及性，并降低了对 GATA 基序的可及性。DLX3 转录模块在 ETO2：：GLIS2 AMKL 和一些侵袭性小儿骨肉瘤中全面富集。重要的是，DLX3 敲除消除了该 ETO2：：GLIS2 iPSC 模型中白血病的发生。总的来说，一种新的人类 iPSC 衍生的 AMKL 模型的表征表明，成骨同源框转录因子 DLX3 的劫持是由 ETO2：：GLIS2 融合癌基因驱动的染色质变化和白血病发生的重要早期步骤。