Nunukova Alena, Neradil Jakub, Skoda Jan, Jaros Josef, Hampl Ales, Sterba Jaroslav, Veselska Renata
Department of Experimental Biology, Faculty of Science, Masaryk University, 61137 Brno, Czech Republic.
Department of Histology and Embryology, Faculty of Medicine, Masaryk University, 61137 Brno, Czech Republic.
Int J Mol Med. 2015 Jul;36(1):65-72. doi: 10.3892/ijmm.2015.2210. Epub 2015 May 14.
CD133 (also known as prominin-1) is a cell surface glycoprotein that is widely used for the identification of stem cells. Furthermore, its glycosylated epitope, AC133, has recently been discussed as a marker of cancer stem cells in various human malignancies. During our recent experiments on rhabdomyosarcomas (RMS), we unexpectedly identified an atypical nuclear localization of CD133 in a relatively stable subset of cells in five RMS cell lines established in our laboratory. To the best of our knowledge, this atypical localization of CD133 has not yet been proven or analyzed in detail in cancer cells. In the present study, we verified the nuclear localization of CD133 in RMS cells using three independent anti-CD133 antibodies, including both rabbit polyclonal and mouse monoclonal antibodies. Indirect immunofluorescence and confocal microscopy followed by software cross-section analysis, transmission electron microscopy and cell fractionation with immunoblotting were also employed, and all the results undeniably confirmed the presence of CD133 in the nuclei of stable minor subpopulations of all five RMS cell lines. The proportion of cells showing an exclusive nuclear localization of CD133 ranged from 3.4 to 7.5%, with only minor differences observed among the individual anti-CD133 antibodies. Although the role of CD133 in the cell nucleus remains unclear, these results clearly indicate that this atypical nuclear localization of CD133 in a minor subpopulation of cancer cells is a common phenomenon in RMS cell lines.
CD133（也称为prominin-1）是一种细胞表面糖蛋白，广泛用于鉴定干细胞。此外，其糖基化表位AC133最近已被讨论为各种人类恶性肿瘤中癌症干细胞的标志物。在我们最近对横纹肌肉瘤（RMS）的实验中，我们意外地在我们实验室建立的五种RMS细胞系中相对稳定的细胞亚群中发现了CD133的非典型核定位。据我们所知，CD133的这种非典型定位在癌细胞中尚未得到证实或详细分析。在本研究中，我们使用三种独立的抗CD133抗体（包括兔多克隆抗体和小鼠单克隆抗体）验证了RMS细胞中CD133的核定位。还采用了间接免疫荧光和共聚焦显微镜检查，随后进行软件横截面分析、透射电子显微镜检查和免疫印迹细胞分级分离，所有结果都无可否认地证实了所有五种RMS细胞系稳定的小亚群细胞核中存在CD133。显示CD133仅在细胞核中定位的细胞比例在3.4%至7.5%之间，各抗CD133抗体之间仅观察到微小差异。尽管CD133在细胞核中的作用仍不清楚，但这些结果清楚地表明，CD133在癌细胞小亚群中的这种非典型核定位在RMS细胞系中是一种常见现象。
