Department of Neurosurgery, Henry Ford Health System, Detroit, MI 48202, USA.
Int J Oncol. 2012 Nov;41(5):1693-700. doi: 10.3892/ijo.2012.1592. Epub 2012 Aug 21.
In addition to the primary culturing of cancer stem cells (CSCs) from tumor tissues, CSCs are found in established tumor cell lines. However, it is unclear how culture conditions affect CSC enrichment. Additionally, the differentiation potential of cell line-derived CSCs has not been well studied. In our study, the glioblastoma cell lines LN229, T98G, U251n and U87, were cultured as spheres in serum-containing medium (serum spheres) or serum-free medium (serum-free spheres). We found that LN229 and U251n cells expressed multiple stem cell markers such as Nestin, Sox2, Musashi-1 and CD44, and their serum spheres expressed even higher levels of Nestin, Sox2 and Musashi-1 compared to monolayer cells and serum‑free spheres. LN229 and U251n cells showed higher migration and colony formation potential compared to T98G and U87 cells, which did not express Nestin, Sox2 and Musashi-1. Serum spheres of LN229 and U251n cells also exhibited higher resistance to temozolomide compared to serum-free spheres. All tumor cell lines showed neuronal differentiation (Tuj-1 positive). Only U251n serum spheres exhibited both astrocytic (GFAP‑positive) and neuronal differentiation. We conclude that sphere culture in serum-containing medium provides the most efficient enrichment of cancer stem cells. U251n cells are distinguished from other tumor cells due to their potential for multilineage differentiation.
除了从肿瘤组织中培养癌症干细胞（CSC）外，CSC 还存在于已建立的肿瘤细胞系中。然而，培养条件如何影响 CSC 的富集尚不清楚。此外，细胞系来源的 CSC 的分化潜力尚未得到很好的研究。在我们的研究中，将神经胶质瘤细胞系 LN229、T98G、U251n 和 U87 在含有血清的培养基（血清球）或无血清培养基（无血清球）中培养为球体。我们发现 LN229 和 U251n 细胞表达多种干细胞标志物，如 Nestin、Sox2、Musashi-1 和 CD44，并且它们的血清球表达的 Nestin、Sox2 和 Musashi-1 比单层细胞和无血清球更高。与不表达 Nestin、Sox2 和 Musashi-1 的 T98G 和 U87 细胞相比，LN229 和 U251n 细胞显示出更高的迁移和集落形成潜力。与无血清球相比，LN229 和 U251n 细胞的血清球也表现出更高的替莫唑胺耐药性。所有肿瘤细胞系均显示出神经元分化（Tuj-1 阳性）。只有 U251n 血清球表现出星形胶质细胞（GFAP 阳性）和神经元分化。我们得出结论，含血清的球体培养提供了最有效的癌症干细胞富集。U251n 细胞由于其多能分化的潜力而与其他肿瘤细胞区分开来。
