弥漫性中线胶质瘤（DMG）是一种儿童肿瘤，其特点是能够浸润中枢神经系统，诊断后两年生存率可忽略不计。为了控制局部生长并减缓疾病进展，所有患者都接受放疗。然而，DMG患者常常会出现远处进展。目前对引起肿瘤浸润的原因的线索主要围绕肿瘤微环境，但目前尚无已知的决定因素来预测其浸润程度。在本研究中，我们使用患者来源的胶质瘤干细胞（GSCs）创建了患者特异性的三维化身，用于模拟个体间的浸润和阐明细胞支持机制。我们显示，三维GSC模型能够反映父代肿瘤的浸润行为，从而证明了DMG浸润是肿瘤细胞自主特性的能力。此外，我们区分了两种迁移模式，即间充质型和变形虫样，将变形虫样模态与来源于最具浸润性肿瘤的GSC相关联。通过对器官样体和原发肿瘤的转录组学分析，我们进一步将浸润的变形虫样肿瘤确定为少突胶质细胞前体样肿瘤，其具有高度可收缩的细胞骨架和降低的粘附能力，而这是由BMP7的关键过表达所驱动。最后，我们解释了在BMP7刺激下激活的MEK、ERK和Rho/ROCK激酶作为可操作的靶点，控制肿瘤细胞的运动能力。我们的研究结果确定了两个新的治疗途径。首先，患者来源的GSCs代表了一种用于根据放疗策略进行患者分层的预测工具。其次，自分泌和短程BMP7相关信号成为可药物靶点，以防止DMG的扩散和转移。© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Neuro-Oncology.

Diffuse midline gliomas (DMG) are pediatric tumors with negligible two-year survival after diagnosis characterized by their ability to infiltrate the central nervous system. In the hope of controlling the local growth and slowing the disease all patients receive radiotherapy. However, distant progression occurs frequently in DMG patients. Current clues as to what causes tumor infiltration circle mainly around the tumor microenvironment, but there are currently no known determinants to predict the degree of invasiveness.In this study we use patient-derived glioma stem cells (GSCs) to create patient-specific 3D avatars to model interindividual invasion and elucidate the cellular supporting mechanisms.We show that GSC models in 3D mirror the invasive behavior of the parental tumors, thus proving the ability of DMG to infiltrate as an autonomous characteristic of tumor cells. Furthermore, we distinguished two modes of migration, mesenchymal and amoeboid-like, and associated the amoeboid-like modality with GSCs derived from the most invasive tumors. Using transcriptomics of both organoids and primary tumors, we further characterized the invasive amoeboid-like tumors as oligodendrocyte progenitor-like, with highly contractile cytoskeleton and reduced adhesion ability driven by crucial over-expression of BMP7. Finally, we deciphered MEK, ERK and Rho/ROCK kinases activated downstream of the BMP7 stimulation as actionable targets controlling tumor cell motility.Our findings identify two new therapeutic avenues. First, patient-derived GSCs represent a predictive tool for patient stratification in order to adapt irradiation strategies. Second, autocrine and short-range BMP7-related signaling becomes a druggable target to prevent DMG spread and metastasis.© The Author(s) 2023. Published by Oxford University Press on behalf of the Society for Neuro-Oncology.