BACKGROUND: Intraventricular penetration is rare in glioblastoma (GBM). Whether the ependymal region including the ependyma and subventricular zone (SVZ) can prevent GBM invasion remains unclear. METHODS: Magnetic resonance imaging (MRI) and haematoxylin–eosin (HE) staining were performed to evaluate the size and anatomical locations of GBM. Binary logistic regression analysis was used to assess the correlation between tumour-ependyma contact, ventricle penetration and clinical characteristics. Cell migration and invasion were assessed via Transwell assays and an orthotopic transplantation model. RESULTS: Among 357 patients with GBM, the majority (66 %) showed ependymal region contact, and 34 patients (10 %) showed ventricle penetration of GBM. GBM cells were spread along the ependyma in the orthotopic transplantation model. The longest tumour diameter was an independent risk factor for GBM-ependymal region contact, as demonstrated by univariate (OR = 1.706, p < 0.0001) and multivariate logistic regression analyses (OR = 1.767, p < 0.0001), but was not associated with ventricle penetration. Cerebrospinal fluid (CSF) could significantly induce tumour cell migration (p < 0.0001), and GBM could grow in CSF. Compared with those from the cortex, cells from the ependymal region attenuated the invasion of C6 whether cocultured with C6 or mixed with Matrigel (p = 0.0054 and p = 0.0488). Immunofluorescence analysis shows a thin gap with GFAP expression delimiting the tumour and ependymal region. CONCLUSION: The ependymal region might restrict GBM cells from entering the ventricle via a nonmechanical force. Further studies in this area may reveal mechanisms that occur in GBM patients and may enable the design of new therapeutic strategies.

中文翻译：

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室管膜区阻止 GBM 通过非机械力进入心室

背景：脑室内穿透在胶质母细胞瘤 (GBM) 中很少见。包括室管膜和室下区（SVZ）在内的室管膜区域是否可以防止 GBM 侵袭仍不清楚。方法：进行磁共振成像 (MRI) 和苏木精-伊红 (HE) 染色以评估 GBM 的大小和解剖位置。二元逻辑回归分析用于评估肿瘤-室管膜接触、心室穿透和临床特征之间的相关性。通过 Transwell 测定和原位移植模型评估细胞迁移和侵袭。结果：在 357 名 GBM 患者中，大多数（66%）显示室管膜区接触，34 名患者（10%）显示 GBM 穿透心室。在原位移植模型中，GBM 细胞沿室管膜分布。如单变量（OR = 1.706，p < 0.0001）和多变量逻辑回归分析（OR = 1.767，p < 0.0001）所示，最长肿瘤直径是 GBM 室管膜区接触的独立危险因素，但与心室无关渗透。脑脊液 (CSF) 可显着诱导肿瘤细胞迁移 (p < 0.0001)，GBM 可在 CSF 中生长。与来自皮质的细胞相比，来自室管膜区域的细胞减弱了 C6 的侵袭，无论是与 C6 共培养还是与 Matrigel 混合（p = 0.0054 和 p = 0.0488）。免疫荧光分析显示 GFAP 表达的薄间隙界定了肿瘤和室管膜区域。结论：室管膜区域可能会限制 GBM 细胞通过非机械力进入心室。