Skoda Jan, Hermanova Marketa, Loja Tomas, Nemec Pavel, Neradil Jakub, Karasek Petr, Veselska Renata
Laboratory of Tumor Biology, Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic.
Department of Pediatric Oncology, University Hospital Brno and Faculty of Medicine, Masaryk University, Brno, Czech Republic.
PLoS One. 2016 Jul 14;11(7):e0159255. doi: 10.1371/journal.pone.0159255. eCollection 2016.
Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies. Its dismal prognosis is often attributed to the presence of cancer stem cells (CSCs) that have been identified in PDAC using various markers. However, the co-expression of all of these markers has not yet been evaluated. Furthermore, studies that compare the expression levels of CSC markers in PDAC tumor samples and in cell lines derived directly from those tumors are lacking. Here, we analyzed the expression of putative CSC markers-CD24, CD44, epithelial cell adhesion molecule (EpCAM), CD133, and nestin-by immunofluorescence, flow cytometry and quantitative PCR in 3 PDAC-derived cell lines and by immunohistochemistry in 3 corresponding tumor samples. We showed high expression of the examined CSC markers among all of the cell lines and tumor samples, with the exception of CD24 and CD44, which were enriched under in vitro conditions compared with tumor tissues. The proportions of cells positive for the remaining markers were comparable to those detected in the corresponding tumors. Co-expression analysis using flow cytometry revealed that CD24+/CD44+/EpCAM+/CD133+ cells represented a significant population of the cells (range, 43 to 72%) among the cell lines. The highest proportion of CD24+/CD44+/EpCAM+/CD133+ cells was detected in the cell line derived from the tumor of a patient with the shortest survival. Using gene expression profiling, we further identified the specific pro-tumorigenic expression profile of this cell line compared with the profiles of the other two cell lines. Together, CD24+/CD44+/EpCAM+/CD133+ cells are present in PDAC cell lines derived from primary tumors, and their increased proportion corresponds with a pro-tumorigenic gene expression profile.
胰腺导管腺癌（PDAC）仍然是最致命的恶性肿瘤之一。其预后不佳通常归因于癌症干细胞（CSC）的存在，这些癌症干细胞已通过各种标志物在PDAC中得到鉴定。然而，尚未对所有这些标志物的共表达情况进行评估。此外，缺乏比较PDAC肿瘤样本和直接源自这些肿瘤的细胞系中CSC标志物表达水平的研究。在此，我们通过免疫荧光、流式细胞术和定量PCR分析了3种源自PDAC的细胞系中假定的CSC标志物——CD24、CD44、上皮细胞粘附分子（EpCAM）、CD133和巢蛋白的表达，并通过免疫组织化学分析了3个相应肿瘤样本中的表达情况。我们发现，除了CD24和CD44在体外条件下相对于肿瘤组织有所富集外，所有细胞系和肿瘤样本中所检测的CSC标志物均呈高表达。其余标志物阳性的细胞比例与相应肿瘤中检测到的比例相当。使用流式细胞术进行的共表达分析显示，CD24+/CD44+/EpCAM+/CD133+细胞在细胞系中占相当大的比例（范围为43%至72%）。在源自生存期最短患者肿瘤的细胞系中检测到的CD24+/CD44+/EpCAM+/CD133+细胞比例最高。通过基因表达谱分析，我们进一步确定了该细胞系与其他两个细胞系相比特定的促肿瘤发生表达谱。总之，CD24+/CD44+/EpCAM+/CD133+细胞存在于源自原发性肿瘤的PDAC细胞系中，其比例增加与促肿瘤发生基因表达谱相对应。
