Glioblastoma (GBM) is a malignant and aggressive central nervous tumor that originates from astrocytes. These pathogenic astrocytes divide rapidly and are sustained by enormous network of blood vessels via which they receive requisite nutrients. It well proven that GBM microenvironment is extremely infiltrated by myeloid-derived suppressor cells (MDSCs). MDSCs are a heterogeneous cluster of immature myeloid progenitors. They are key mediates in immune suppression as well as sustenance glioma growth, invasion, vascularization, and upsurge of regulatory T cells via different molecules. MDSCs are often elevated in the peripheral blood of patients with GBM. MDSCs in the peripheral blood as well as those infiltrating the GBM microenvironment correlated with poor prognosis. Also, an upsurge in circulating MDSCs in the peripheral blood of patients with GBM was observed compared to benign and grade I/II glioma patients. GBM patients with good prognosis presented with reduced MDSCs as well as augmented dendritic cells. Almost all chemotherapeutic medication for GBM has shown no obvious improvement in overall survival in patients. Nevertheless, low-dose chemotherapies were capable of suppressing the levels of MDSCs in GBM as well as multiple tumor models with metastatic to the brain. Thus, MDSCs are potential diagnostic as well as therapeutic biomarkers for GBM patients.

中文翻译：

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阐明胶质母细胞瘤中髓源性抑制细胞的关键致病、诊断和治疗生物标志物潜力

胶质母细胞瘤（GBM）是一种起源于星形胶质细胞的恶性和侵袭性中枢神经肿瘤。这些致病性星形胶质细胞分裂迅速，并由巨大的血管网络维持，通过这些网络它们获得必需的营养。充分证明GBM微环境被髓源抑制细胞（MDSCs）极度浸润。MDSCs 是未成熟髓系祖细胞的异质簇。它们是免疫抑制以及维持胶质瘤生长、侵袭、血管化和通过不同分子产生的调节性 T 细胞激增的关键介质。在 GBM 患者的外周血中，MDSCs 通常升高。外周血中的 MDSC 以及那些浸润 GBM 微环境的 MDSC 与预后不良相关。还，与良性和 I/II 级胶质瘤患者相比，观察到 GBM 患者外周血中循环 MDSC 的增加。预后良好的 GBM 患者表现为 MDSC 减少以及树突细胞增多。几乎所有用于 GBM 的化疗药物都没有显示出患者总生存期的明显改善。尽管如此，低剂量化疗能够抑制 GBM 以及多种脑转移肿瘤模型中 MDSC 的水平。因此，MDSCs 是 GBM 患者潜在的诊断和治疗生物标志物。几乎所有用于 GBM 的化疗药物都没有显示出患者总生存期的明显改善。尽管如此，低剂量化疗能够抑制 GBM 以及多种脑转移肿瘤模型中 MDSC 的水平。因此，MDSCs 是 GBM 患者潜在的诊断和治疗生物标志物。几乎所有用于 GBM 的化疗药物都没有显示出患者总生存期的明显改善。尽管如此，低剂量化疗能够抑制 GBM 以及多种脑转移肿瘤模型中 MDSC 的水平。因此，MDSCs 是 GBM 患者潜在的诊断和治疗生物标志物。