Human malignant hematopoietic stem and progenitor cells (HSPCs) reside in bone marrow (BM) niches, which remain challenging to explore due to limited in vivo accessibility and constraints with humanized animal models. Several in vitro systems have been established to culture patient-derived HSPCs in specific microenvironments, but they do not fully recapitulate the complex features of native bone marrow. Our group previously reported that human osteoblastic BM niches (O-N), engineered by culturing mesenchymal stromal cells within three-dimensional (3D) porous scaffolds under perfusion flow in a bioreactor system, are capable of maintaining, expanding, and functionally regulating healthy human cord blood-derived HSPCs. Here, we first demonstrate that this 3D O-N can sustain malignant CD34⁺ cells from acute myeloid leukemia (AML) and myeloproliferative neoplasm patients for up to 3 wk. Human malignant cells distributed in the bioreactor system mimicking the spatial distribution found in native BM tissue, where most HSPCs remain linked to the niches and mature cells are released to the circulation. Using human adipose tissue-derived stromal vascular fraction cells, we then generated a stromal-vascular niche and demonstrated that O-N and stromal-vascular niche differentially regulate leukemic UCSD-AML1 cell expansion, immunophenotype, and response to chemotherapy. The developed system offers a unique platform to investigate human leukemogenesis and response to drugs in customized environments, mimicking defined features of native hematopoietic niches and compatible with the establishment of personalized settings.

人类恶性造血干细胞和祖细胞 (HSPC) 存在于骨髓 (BM) 壁龛中，由于体内可及性有限和人源化动物模型的限制，探索这些细胞仍然具有挑战性。已经建立了几种体外系统来在特定的微环境中培养患者衍生的 HSPC，但它们并没有完全概括原生骨髓的复杂特征。我们小组先前报道，通过在生物反应器系统中的灌注流下在三维 (3D) 多孔支架内培养间充质基质细胞而设计的人类成骨细胞 BM 生态位 (ON) 能够维持、扩展和功能调节健康的人类脐带血-衍生的HSPC。在这里，我们首先证明这种 3D ON 可以维持恶性 CD34 ⁺来自急性髓性白血病 (AML) 和骨髓增生性肿瘤患者的细胞长达 3 周。人类恶性细胞分布在生物反应器系统中，模仿天然 BM 组织中的空间分布，其中大多数 HSPC 仍然与生态位相连，成熟细胞被释放到循环中。使用人类脂肪组织衍生的基质血管部分细胞，我们随后生成了基质血管生态位，并证明 ON 和基质血管生态位差异调节白血病 UCSD-AML1 细胞扩增、免疫表型和对化疗的反应。开发的系统提供了一个独特的平台来研究人类白血病的发生和在定制环境中对药物的反应，模仿天然造血生态位的定义特征，并与个性化设置的建立兼容。