B 细胞祖细胞急性淋巴细胞白血病 (BCP-ALL) 是最常见的儿童恶性肿瘤，由多种基因改变导致成熟停滞和异常祖 B 细胞积累。目前的化疗方案已经取得了良好的结果，但与显着的毒性和副作用风险相关，这凸显了高效、毒性较小的靶向药物的必要性，即使是在具有良好结果的亚型中也是如此。在这里，我们使用多模式单细胞测序描绘了 23 个儿童 BCP-ALL 的转录、表观遗传和免疫表型特征，这些 BCP-ALL 属于 BCR::ABL1 阳性、ETV6::RUNX1 阳性、高超二倍体和最近发现的 DUX4 -重新排列的（DUX4-r）亚型。 ALL 细胞沿正常造血分化轴的投影揭示了不同 BCP-ALL 亚型之间成熟模式的多样性。 BCR::ABL1-、ETV6::RUNX1-阳性和高超二倍体细胞主要表现出与正常 B 细胞的相似性，而 DUX4-r ALL 细胞也表现出类似于成熟 B 细胞的转录特征。着眼于 DUX4-r 亚型，我们发现母细胞群体表现出针对非造血细胞、骨髓细胞和 T 细胞谱系的多谱系启动，而且还激活了 PI3K/AKT 信号传导，使细胞对体内 PI3K 抑制敏感。鉴于 DUX4-r 母细胞的多谱系启动与骨髓标记物 CD371 (CLL-1) 的异常表达，我们产生了嵌合抗原受体 T 细胞，它有效地消除了体内 DUX4-r ALL 细胞。这些结果提供了 BCP-ALL 在单细胞水平上的详细表征，并揭示了 DUX4-r 亚型的治疗弱点，对理解 ALL 生物学和新的治疗策略具有重要意义。版权所有 © 2024 美国血液学会。

B cell progenitor acute lymphoblastic leukemia (BCP-ALL) is the most common childhood malignancy, driven by multiple genetic alterations that cause maturation arrest and accumulation of abnormal progenitor B cells. Current treatment protocols with chemotherapy have led to favorable outcomes but are associated with significant toxicity and risk of side effects, highlighting the necessity for highly effective, less toxic, targeted drugs, even in subtypes with a favorable outcome. Here, we used multimodal single-cell sequencing to delineate the transcriptional, epigenetic, and immunophenotypic characteristics of 23 childhood BCP-ALLs, belonging to the BCR::ABL1-positive, ETV6::RUNX1-positive, high hyperdiploid, and recently discovered DUX4-rearranged (DUX4-r) subtypes. Projection of the ALL cells along the normal hematopoietic differentiation axis revealed a diversity in the maturation pattern between the different BCP-ALL subtypes. Whereas the BCR::ABL1-, ETV6::RUNX1-positive, and high hyperdiploidy cells mainly showed similarities to normal pro-B cells, the DUX4-r ALL cells also displayed transcriptional signatures resembling mature B cells. Focusing on the DUX4-r subtype, we found that the blast population displayed multilineage priming toward non-hematopoietic cells, myeloid, and T cell lineages, but also an activation of PI3K/AKT signaling that sensitized the cells to PI3K inhibition in vivo. Given the multilineage priming of the DUX4-r blasts with aberrant expression of the myeloid marker CD371 (CLL-1), we generated chimeric antigen receptor T cells, which effectively eliminated DUX4-r ALL cells in vivo. These results provide a detailed characterization of BCP-ALL at the single-cell level and reveal therapeutic vulnerabilities in the DUX4-r subtype with implications for the understanding of ALL biology and new therapeutic strategies.Copyright © 2024 American Society of Hematology.