College of Pharmaceutical Sciences, Soochow University, Suzhou, China.
Cancer biology program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA, USA.
Lab Invest. 2020 Sep;100(9):1208-1222. doi: 10.1038/s41374-020-0443-2. Epub 2020 May 26.
Aberrant activation of the hedgehog (Hh) signaling pathway is associated with the formation of medulloblastoma (MB), the most common malignant pediatric brain tumor. However, tumor cells from human and mouse MB can not be passaged or preserved after being adherently cultured. Moreover, Hh signaling in MB cells is inactivated in such culture. Here we demonstrate that MB cells are capable of forming tumoroids (tumor spheroids) in vitro under optimized conditions, which can be further passaged and cryopreserved. More importantly, MB cells maintain Hh pathway activation and cell proliferation in tumoroids. Our studies further reveal that tumoroids-forming capacity of MB cells relies on astrocytes, a major component of the MB microenvironment. Astrocytes facilitate the formation of MB tumoroids by secreting sonic hedgehog (Shh) and generating astrocyte-derived extracellular matrix. These findings demonstrate the critical role of stromal astrocytes in supporting the survival and proliferation of MB cells in vitro. This study establishes a valid model for long-term culture of primary MB cells, which could be greatly beneficial for future investigation of MB tumorigenicity and the development of improved approaches to treat MB.
Hedgehog (Hh) 信号通路的异常激活与成神经管细胞瘤 (MB) 的形成有关，MB 是最常见的小儿脑恶性肿瘤。然而，来自人和鼠 MB 的肿瘤细胞在贴壁培养后不能传代或保存。此外，这种培养方式会使 MB 细胞中的 Hh 信号失活。在这里，我们证明了 MB 细胞在优化条件下能够在体外形成肿瘤球（肿瘤球体），这些肿瘤球可以进一步传代和冷冻保存。更重要的是，MB 细胞在肿瘤球中保持 Hh 通路的激活和细胞增殖。我们的研究进一步揭示了 MB 细胞形成肿瘤球的能力依赖于星形胶质细胞，这是 MB 微环境的主要组成部分。星形胶质细胞通过分泌 sonic hedgehog (Shh) 和产生星形胶质细胞衍生的细胞外基质来促进 MB 肿瘤球的形成。这些发现表明基质星形胶质细胞在体外支持 MB 细胞的存活和增殖中起着关键作用。这项研究建立了一个用于原代 MB 细胞长期培养的有效模型，这对于未来研究 MB 的致瘤性以及开发改善 MB 治疗方法有很大的帮助。
