Chonan Yuta, Taki Sotaro, Sampetrean Oltea, Saya Hideyuki, Sudo Ryo
Department of System Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan.
Integr Biol (Camb). 2017 Sep 18;9(9):762-773. doi: 10.1039/c7ib00091j.
Glioblastoma (GBM) is a highly invasive primary brain tumor that displays cellular heterogeneity, which is composed of glioma initiating cells (GICs) and their differentiated progeny. GICs play an important role in driving aggressive invasion. In particular, the interaction between GICs and blood vessels is critical because blood vessels are known to serve as routes for the invasion of GICs. However, the effect of endothelial cells on the three-dimensional (3D) invasion process of GICs as well as the spatial relationship between GICs and their differentiated progeny remains unclear. Here, we utilized a microfluidic device to recapitulate the 3D brain tumor microenvironments constituted by human umbilical vein endothelial cells (HUVECs) and type I collagen. Using the device, we found that HUVECs promoted the 3D invasion of heterogeneous glioma cell populations into type I collagen gel. The invasion induced by HUVECs was predominantly preceded by cells positive for nestin, a neural stem cell marker. In contrast, cells positive for tubulin β3 (TUBB3), a differentiated cell marker, rarely preceded invasion. In addition, HUVECs induced the upregulation of TUBB3 in GICs. Finally, we found that the genes associated with invasion, such as integrins α2 and β3, were significantly upregulated in the presence of HUVECs. These results as well as the experimental approach provide valuable knowledge for the development of effective therapeutic strategies targeting the aggressive invasion of GBM.
胶质母细胞瘤（GBM）是一种具有高度侵袭性的原发性脑肿瘤，表现出细胞异质性，由胶质瘤起始细胞（GICs）及其分化后代组成。GICs在驱动侵袭性浸润中起重要作用。特别是，GICs与血管之间的相互作用至关重要，因为血管是GICs浸润的途径。然而，内皮细胞对GICs三维（3D）侵袭过程的影响以及GICs与其分化后代之间的空间关系仍不清楚。在这里，我们利用微流控装置来模拟由人脐静脉内皮细胞（HUVECs）和I型胶原构成的3D脑肿瘤微环境。使用该装置，我们发现HUVECs促进了异质性胶质瘤细胞群体向I型胶原凝胶中的三维侵袭。HUVECs诱导的侵袭主要由神经干细胞标志物巢蛋白阳性的细胞先于其发生。相比之下，分化细胞标志物微管蛋白β3（TUBB3）阳性的细胞很少先于侵袭发生。此外，HUVECs诱导GICs中TUBB3的上调。最后，我们发现与侵袭相关的基因，如整合素α2和β3，在有HUVECs存在时显著上调。这些结果以及实验方法为开发针对GBM侵袭性浸润的有效治疗策略提供了有价值的知识。
