Department of Cellular Therapy, Oslo University Hospital, Radiumhospitalet, Oslo, Norway.
Exp Hematol Oncol. 2013 Jun 6;2(1):16. doi: 10.1186/2162-3619-2-16.
Tumor development is recently hypothesized to depend on a rare cell population with stem cell properties, such cells are called cancer stem cells (CSCs) or tumor-initiating cells (TICs). From various cancer tissues or cancer cell lines, CD133 expressing cells were found to define a unique CSC/TIC phenotype. To study whether that also could be the case in lung cancer, we examined different lung cancer cell lines for CD133 expression.
Among the 4 cell lines studied, only the cell line LC-42 expressed CD133. Therefore, LC-42 was further characterized and studied with special emphasis on identifying the presence of CD133+ CSCs/TICs. FACS sorted CD133high and CD133dim subpopulations from LC-42 showed no differences in soft agar colony-forming capacity and spheres-forming capacity in serum-free cultures. LC-42 cells contained Side Population (SP), and only SP cells were able to form spheres. Furthermore, Nanog expression was significantly higher in SP than in non-SP. However, no difference was observed of CD133 expression in SP and non-SP. When CD133high and CD133dim cells were serially xeno-transplanted in NOD/SCID mice, both formed tumours similar to their parental LC-42 cells. There were no expression differences for NANOG, OCT4 and SOX2 examined immunohistochemically in the xenografts from both cell fractions.
Our data do not show a difference in tumorigenic potential of CD133high and CD133dim cells with respect to any of the parameters analyzed in vitro and in vivo, suggesting that CD133 expression is not restricted to cancer-initiating cells in the human lung cancer cell line LC-42.
肿瘤的发生发展被认为依赖于具有干细胞特性的稀有细胞群体，这些细胞被称为癌症干细胞（CSCs）或肿瘤起始细胞（TICs）。从各种癌症组织或癌细胞系中，发现表达 CD133 的细胞定义了独特的 CSC/TIC 表型。为了研究这是否也适用于肺癌，我们检查了不同的肺癌细胞系中 CD133 的表达情况。
在所研究的 4 个细胞系中，只有 LC-42 细胞系表达 CD133。因此，LC-42 进一步进行了特征描述和研究，特别强调鉴定 CD133+CSC/TIC 的存在。FACS 从 LC-42 中分选出 CD133high 和 CD133dim 亚群，在无血清培养的软琼脂集落形成能力和球体形成能力方面没有差异。LC-42 细胞含有侧群（SP），只有 SP 细胞能够形成球体。此外，SP 中的 Nanog 表达明显高于非 SP。然而，在 SP 和非 SP 中，CD133 的表达没有差异。当 CD133high 和 CD133dim 细胞在 NOD/SCID 小鼠中连续异种移植时，两者均形成与亲本 LC-42 细胞相似的肿瘤。在异种移植物中，通过免疫组织化学检测，未观察到 NANOG、OCT4 和 SOX2 的表达差异。
我们的数据表明，在体外和体内分析的任何参数方面，CD133high 和 CD133dim 细胞的致瘤潜力没有差异，这表明 CD133 表达不仅限于人肺癌细胞系 LC-42 中的肿瘤起始细胞。
