Hamilton Lloyd, Astell Katy R, Velikova Gergana, Sieger Dirk
Centre for Neuroregeneration, University of Edinburgh , Edinburgh, United Kingdom .
Zebrafish. 2016 Dec;13(6):523-534. doi: 10.1089/zeb.2016.1339. Epub 2016 Oct 25.
Glioblastoma multiforme is the most common and deadliest form of brain cancer. Glioblastomas are infiltrated by a high number of microglia, which promote tumor growth and surrounding tissue invasion. However, it is unclear how microglia and glioma cells physically interact and if there are differences, depending on glioma cell type. Hence, we have developed a novel live imaging assay to study microglia-glioma interactions in vivo in the zebrafish brain. We transplanted well-established human glioblastoma cell lines, U87 and U251, into transgenic zebrafish lines with labelled macrophages/microglia. Our confocal live imaging results show distinct interactions between microglia and U87, as well as U251 glioblastoma cells that differ in number and nature. Importantly these interactions do not appear to be antitumoral as zebrafish microglia do not engulf and phagocytose the human glioblastoma cells. Finally, xenotransplants into the irf8 zebrafish mutant that lacks microglia, as well as pharmacological inhibition of the CSF-1 receptor (CSF-1R) on microglia, confirm a prominent role for zebrafish microglia in promoting human glioblastoma cell growth. This new model will be an important tool for drug screening and the development of future immunotherapeutics targeting microglia within glioma.
多形性胶质母细胞瘤是最常见且最致命的脑癌形式。胶质母细胞瘤中有大量小胶质细胞浸润，这些小胶质细胞会促进肿瘤生长和周围组织侵袭。然而，目前尚不清楚小胶质细胞与胶质瘤细胞如何进行物理相互作用，以及是否存在差异（取决于胶质瘤细胞类型）。因此，我们开发了一种新型的活体成像检测方法，用于在斑马鱼大脑中体内研究小胶质细胞与胶质瘤的相互作用。我们将成熟的人胶质母细胞瘤细胞系U87和U251移植到带有标记巨噬细胞/小胶质细胞的转基因斑马鱼品系中。我们的共聚焦活体成像结果显示，小胶质细胞与U87以及U251胶质母细胞瘤细胞之间存在明显不同数量和性质的相互作用。重要的是，这些相互作用似乎并非抗肿瘤作用，因为斑马鱼小胶质细胞不会吞噬和清除人胶质母细胞瘤细胞。最后，将肿瘤异种移植到缺乏小胶质细胞的irf8斑马鱼突变体中，以及对小胶质细胞上的集落刺激因子1受体（CSF-1R）进行药理学抑制，证实了斑马鱼小胶质细胞在促进人胶质母细胞瘤细胞生长中起重要作用。这种新模型将成为药物筛选以及未来针对胶质瘤内小胶质细胞的免疫治疗开发的重要工具。
