Collins Rebecca R J, Florke Gee Rebecca R, Tozandehjani Sima, Bayat Tara, Hoyos Sanchez Maria Camila, Gutierrez Juan Sebastian Solano, Breznik Barbara, Lee Anna K, Peters Samuel T, Connelly Jon P, Pruett-Miller Shondra M, Roussel Martine F, Rakheja Dinesh, Tillman Heather S, Potts Patrick Ryan, Fon Tacer Klementina
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
School of Veterinary Medicine, Texas Tech University, 7671 Evans Dr., Amarillo, TX, 79106, USA.
Acta Neuropathol Commun. 2025 Jul 28;13(1):164. doi: 10.1186/s40478-025-02055-3.
Medulloblastoma (MB) is the most malignant childhood brain cancer. Group 3 MB (G3 MB) subtype accounts for about 25% of MB and is associated with the worst outcomes. Herein, we report that more than half of G3 MB tumors express melanoma antigens (MAGEs), which are potential prognostic and therapeutic markers. MAGEs are cancer-testis antigens, aberrantly expressed in several adult cancers, and associated with poorer prognosis and therapy resistance; however, their role in pediatric cancers is mostly unknown. This study aimed to determine whether MAGEs are activated and important in pediatric MB. We obtained formalin-fixed paraffin-embedded tumor samples of 34 patients, collected between 2008 and 2015 at the Children's Medical Center in Dallas and applied our validated reverse transcription quantitative PCR (RT-qPCR) assay to measure the expression of 23 MAGE genes. To validate our data, we analyzed published datasets from pediatric MB tumors and patient-derived orthotopic xenografts, totaling 949 patients. Our RT-qPCR analysis suggested that MAGEs were expressed in G3/4MB. Further mining of bulk and single-cell RNA-sequencing datasets confirmed that 50-75% of G3 tumors activate several MAGEs. Intriguingly, single-cell data analysis showed that MAGEs are expressed in distinct subsets of cells in MAGE-positive tumors and are not activated in mouse genetic models, suggesting they contribute to the tumor heterogeneity and species-specificity of G3 MB. We then examined how MAGE expression affects the growth and oncogenic potential by CRISPR-Cas9- and siRNA-mediated gene depletion. Depletion of MAGEAs, -B2, and -Cs altered cell survival, viability, and clonogenic growth due to decreased proliferation and increased apoptosis of MAGE-positive MB cells. These findings suggested that targeting MAGEs could represent a viable therapeutic strategy for G3 MB. A deeper understanding of MAGE regulation and function is warranted and could aid in improving prognostic and therapeutic approaches for this poorly characterized subgroup of pediatric brain tumors.
髓母细胞瘤（MB）是最恶性的儿童脑癌。3组MB（G3 MB）亚型约占MB的25%，且与最差的预后相关。在此，我们报告超过一半的G3 MB肿瘤表达黑色素瘤抗原（MAGEs），这些抗原是潜在的预后和治疗标志物。MAGEs是癌-睾丸抗原，在几种成人癌症中异常表达，并与较差的预后和治疗抗性相关；然而，它们在儿童癌症中的作用大多未知。本研究旨在确定MAGEs在儿童MB中是否被激活以及是否重要。我们获取了2008年至2015年期间在达拉斯儿童医疗中心收集的34例患者的福尔马林固定石蜡包埋肿瘤样本，并应用我们经过验证的逆转录定量PCR（RT-qPCR）检测方法来测量23个MAGE基因的表达。为了验证我们的数据，我们分析了来自儿童MB肿瘤和患者来源的原位异种移植的已发表数据集，共计949例患者。我们的RT-qPCR分析表明MAGEs在G3/4MB中表达。对批量和单细胞RNA测序数据集的进一步挖掘证实，50%-75%的G3肿瘤激活了几种MAGEs。有趣的是，单细胞数据分析表明MAGEs在MAGE阳性肿瘤的不同细胞亚群中表达，并且在小鼠遗传模型中未被激活，这表明它们导致了G3 MB的肿瘤异质性和物种特异性。然后，我们通过CRISPR-Cas9和siRNA介导的基因缺失来研究MAGE表达如何影响生长和致癌潜力。由于MAGE阳性MB细胞的增殖减少和凋亡增加，MAGEA、-B2和-C的缺失改变了细胞存活、活力和克隆生长。这些发现表明，靶向MAGEs可能是G3 MB的一种可行治疗策略。有必要更深入地了解MAGE的调控和功能，这可能有助于改善针对这种特征不明确的儿童脑肿瘤亚组的预后和治疗方法。
