Radiosensitivity of Patient-Derived Glioma Stem Cell 3-Dimensional Cultures to Photon, Proton, and Carbon Irradiation
Radiosensitivity of Patient-Derived Glioma Stem Cell 3-Dimensional Cultures to Photon, Proton, and Carbon Irradiation
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DOI：
10.1016/j.ijrobp.2015.06.015
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发表时间：
2016-05-01
影响因子：
7
通讯作者：
Abdollahi, Amir
中科院分区：
文献类型：
--
作者：
Chiblak, Sara;Tang, Zili;Abdollahi, Amir
目的：在三维（3D）模型中研究不同CD133状态的原发性胶质瘤干细胞（GSC）培养物在光子、质子和碳辐照后的放射敏感性。方法和材料：从6例胶质母细胞瘤患者的肿瘤标本中建立人原代GSC球体培养物。人U87MG作为典型的胶质母细胞瘤耐辐射细胞系。细胞悬浮液通过GSC球体的机械解离产生，并在照射前嵌入半固体三维基质中。显微镜下人工计数球状菌落。细胞也被回收并荧光定量。流式细胞术检测CD133表达及DNA损伤情况。结果：6种GSC培养中cd133（+）细胞的比例在0.014% ~ 96%之间变化，与镀效率和存活比例无显著相关性。NCH644、NCH421k、NCH441和NCH636是4种最耐光子辐射的GSC培养物。质子辐照的克隆存活率显示相对生物有效性（RBE）在0.7-1.20之间。然而，碳辐照使抗光子GSC培养变得敏感，平均RBE为1.87-3.44。这种效应部分归因于GSC修复碳离子诱导的DNA双链断裂的能力受损，这是由残留的DNA修复灶确定的。有趣的是，使用克隆存活作为标准读数，U87细胞的放射敏感性与GSC培养相当。结论：碳辐照在GSC根除中是有效的，与非茎GSC培养相比，RBE范围约为2-3 （U87）。我们的数据强烈建议使用经典的放射生物学终点，如这里使用的3D克隆生存测定和其他GSC特异性标记的整合，进一步探索GSC。(C) 2016 Elsevier Inc.版权所有。
Purpose: To investigate the radiosensitivity of primary glioma stem cell (GSC) cultures with different CD133 status in a 3-dimensional (3D) model after photon versus proton versus carbon irradiation.Methods and Materials: Human primary GSC spheroid cultures were established from tumor specimens of six consented glioblastoma patients. Human U87MG was used as a classical glioblastoma radioresistant cell line. Cell suspensions were generated by mechanical dissociation of GSC spheroids and embedded in a semi-solid 3D matrix before irradiation. Spheroid-like colonies were manually counted by microscopy. Cells were also recovered and quantified by fluorescence. CD133 expression and DNA damage were evaluated by flow cytometry.Results: The fraction ofCD133(+) cells varied between 0.014% and 96% in the six GSC cultures and showed a nonsignificant correlationwith plating efficiency and survival fractions. The 4 most photon-radioresistant GSC cultures were NCH644, NCH421k, NCH441, and NCH636. Clonogenic survival for proton irradiation revealed relative biologic effectiveness (RBE) in the range of 0.7-1.20. However, carbon irradiation rendered the photon-resistant GSC cultures sensitive, with average RBE of 1.87-3.44. This effect was partly attributed to impaired capability of GSC to repair carbon ioneinduced DNA double-strand breaks as determined by residual DNA repair foci. Interestingly, radiosensitivity of U87 cells was comparable to GSC cultures using clonogenic survival as the standard readout.Conclusions: Carbon irradiation is effective in GSC eradication with similar RBE ranges approximately 2-3 as compared with non-stem GSC cultures (U87). Our data strongly suggest further exploration of GSC using classic radiobiology endpoints such as the here-used 3D clonogenic survival assay and integration of additional GSC-specific markers. (C) 2016 Elsevier Inc. All rights reserved.