du Chatinier Aimée, Meel Michaël H, Das Arvid I, Metselaar Dennis S, Waranecki Piotr, Bugiani Marianna, Breur Marjolein, Simonds Erin F, Lu Edbert D, Weiss William A, Garcia Vallejo Juan J, Hoving Eelco W, Phoenix Timothy N, Hulleman Esther
Princess Máxima Center for Pediatric Oncology, Utrecht, the Netherlands.
Department of Pathology, Amsterdam University Medical Centers, Amsterdam, the Netherlands.
Neurooncol Adv. 2022 May 24;4(1):vdac079. doi: 10.1093/noajnl/vdac079. eCollection 2022 Jan-Dec.
Diffuse midline gliomas (DMG) are highly malignant incurable pediatric brain tumors. A lack of effective treatment options highlights the need to investigate novel therapeutic strategies. This includes the use of immunotherapy, which has shown promise in other hard-to-treat tumors. To facilitate preclinical immunotherapeutic research, immunocompetent mouse models that accurately reflect the unique genetic, anatomical, and histological features of DMG patients are warranted.
We established cell cultures from primary DMG mouse models (C57BL/6) that were generated by brainstem targeted intra-uterine electroporation (IUE). We subsequently created allograft DMG mouse models by orthotopically implanting these tumor cells into syngeneic mice. Immunohistochemistry and -fluorescence, mass cytometry, and cell-viability assays were then used to verify that these murine tumors recapitulated human DMG.
We generated three genetically distinct allograft models representing histone 3 wildtype (H3) and K27M-mutant DMG (H3.3 and H3.1). These allograft models recapitulated the histopathologic phenotype of their human counterparts, including their diffuse infiltrative growth and expression of DMG-associated antigens. These murine pontine tumors also exhibited an immune microenvironment similar to human DMG, characterized by considerable myeloid cell infiltration and a paucity of T-lymphocytes and NK cells. Finally, we show that these murine DMG cells display similar sensitivity to histone deacetylase (HDAC) inhibition as patient-derived DMG cells.
We created and validated an accessible method to generate immunocompetent allograft models reflecting different subtypes of DMG. These models adequately recapitulated the histopathology, immune microenvironment, and therapeutic response of human DMG, providing useful tools for future preclinical studies.
弥漫性中线胶质瘤（DMG）是高度恶性的不可治愈的儿童脑肿瘤。缺乏有效的治疗选择凸显了研究新型治疗策略的必要性。这包括使用免疫疗法，该疗法在其他难以治疗的肿瘤中已显示出前景。为了促进临床前免疫治疗研究，需要能够准确反映DMG患者独特遗传、解剖和组织学特征的具有免疫活性的小鼠模型。
我们从通过脑干靶向子宫内电穿孔（IUE）生成的原发性DMG小鼠模型（C57BL/6）中建立了细胞培养物。随后，我们通过将这些肿瘤细胞原位植入同基因小鼠中创建了同种异体移植DMG小鼠模型。然后使用免疫组织化学和荧光、质谱流式细胞术和细胞活力测定来验证这些小鼠肿瘤重现了人类DMG。
我们生成了三种遗传上不同的同种异体移植模型，分别代表组蛋白3野生型（H3）和K27M突变型DMG（H3.3和H3.1）。这些同种异体移植模型重现了其人类对应物的组织病理学表型，包括它们的弥漫性浸润性生长和DMG相关抗原的表达。这些小鼠脑桥肿瘤还表现出与人类DMG相似的免疫微环境，其特征是大量髓样细胞浸润以及T淋巴细胞和NK细胞稀少。最后，我们表明这些小鼠DMG细胞对组蛋白脱乙酰酶（HDAC）抑制的敏感性与患者来源的DMG细胞相似。
我们创建并验证了一种可获取的方法来生成反映不同DMG亚型的具有免疫活性的同种异体移植模型。这些模型充分重现了人类DMG的组织病理学、免疫微环境和治疗反应，为未来的临床前研究提供了有用的工具。
