Ortiz-Sánchez Paula, González-Soto Sara, Villamizar Luz H, Valencia Jaris, Jiménez Eva, Sacedón Rosa, Ramírez Manuel, Fariñas Isabel, Varas Alberto, Fernández-Sevilla Lidia M, Vicente Ángeles
Department of Cell Biology, Faculty of Medicine, Complutense University, Madrid, Spain.
Health Research Institute Hospital 12 de Octubre (Imas12), Madrid, Spain.
Cell Oncol (Dordr). 2025 Feb 12. doi: 10.1007/s13402-025-01043-y.
Central nervous system (CNS) involvement and/or relapse remains one of the most important causes of morbidity/mortality in paediatric B-cell precursor acute lymphoblastic leukaemia (BCP-ALL) patients. To identify novel therapeutic targets and develop less aggressive therapies, a better understanding of the cellular and molecular microenvironment in leptomeningeal metastases is key. Here, we aimed to investigate the formation of metastatic leptomeningeal aggregates and their relevance to the expansion, survival and chemoresistance acquisition of leukaemia cells.
We used BCP-ALL xenograft mouse models, combined with immunohistofluorescence and flow cytometry, to study the development of CNS metastasis and the contribution of leptomeningeal cells to the organisation of leukaemic aggregates. To in vitro mimic the CNS metastasis, we established co-cultures of three-dimensional (3D) ALL cell spheroids and human leptomeningeal cells (hLMCs) and studied the effects on gene expression, proliferation, cytokine production, and chemoresistance.
In xenografted mice, ALL cells infiltrated the CNS at an early stage and, after crossing an ER-TR7 fibroblast-like meningeal cell layer, they proliferated extensively and formed large vascularised leukaemic aggregates supported by a network of podoplanin leptomeningeal cells. In leukaemia spheroid-hLMC co-cultures, unlike conventional 2D co-cultures, meningeal cells strongly promoted the proliferation of leukaemic cells and generated a pro-inflammatory microenvironment. Furthermore, in 3D cell aggregates, leukaemic cells also developed chemoresistance, at least in part due to ABC transporter up-regulation.
Our results provide evidence for the formation of metastatic ALL-leptomeningeal cell aggregates, their pro-inflammatory profile and their contribution to leukaemic cell expansion, survival and chemoresistance in the CNS.
中枢神经系统（CNS）受累和/或复发仍然是小儿B细胞前体急性淋巴细胞白血病（BCP-ALL）患者发病/死亡的最重要原因之一。为了确定新的治疗靶点并开发侵袭性较小的疗法，深入了解软脑膜转移中的细胞和分子微环境是关键。在此，我们旨在研究转移性软脑膜聚集物的形成及其与白血病细胞增殖、存活和获得化疗耐药性的相关性。
我们使用BCP-ALL异种移植小鼠模型，结合免疫组织荧光和流式细胞术，研究中枢神经系统转移的发展以及软脑膜细胞对白血病聚集物形成的作用。为了在体外模拟中枢神经系统转移，我们建立了三维（3D）ALL细胞球体与人软脑膜细胞（hLMCs）的共培养体系，并研究其对基因表达、增殖、细胞因子产生和化疗耐药性的影响。
在异种移植小鼠中，ALL细胞在早期浸润中枢神经系统，穿过ER-TR7成纤维细胞样脑膜细胞层后，它们大量增殖并形成由血小板内皮细胞黏附分子软脑膜细胞网络支持的大型血管化白血病聚集物。在白血病球体-hLMC共培养体系中，与传统的二维共培养不同，脑膜细胞强烈促进白血病细胞的增殖并产生促炎微环境。此外，在3D细胞聚集体中，白血病细胞也产生了化疗耐药性，至少部分原因是ABC转运蛋白上调。
我们的结果为转移性ALL-软脑膜细胞聚集物的形成、其促炎特征及其对中枢神经系统白血病细胞增殖、存活和化疗耐药性的作用提供了证据。
