Maertens Yvonne, Humberg Verena, Erlmeier Franziska, Steffens Sandra, Steinestel Julie, Bögemann Martin, Schrader Andres Jan, Bernemann Christof
Clinic for Urology, University Hospital Muenster, Muenster, Germany.
Institute for Pathology and Pathological Anatomy, Technical University Munich, Munich, Germany.
Oncotarget. 2017 Sep 23;8(50):87710-87717. doi: 10.18632/oncotarget.21197. eCollection 2017 Oct 20.
Analysis of circulating tumor cells (CTCs) has progressed in several tumor entities. However, little is known about CTCs in clear cell renal cell carcinoma (ccRCC) patients. Aim of our studies was to build a stable fundament for isolation of CTCs in ccRCC.
We compared the analytical performance of different CTC isolation methods with regard to yield and purity: EpCAM based enrichment, leukocyte depletion and size based enrichment. EpCAM and cytokeratin 8 (KRT8) as biomarker for CTCs expression were evaluated in ccRCC cell lines as well as clinical samples.
While the EpCAM based approach failed to successfully isolate tumor cells, CD45 based approaches showed intermediate recovery rates. The cell-size based Parsortix system showed highest recovery rates. EpCAM expression was low or absent in most cell lines as well as in clinical samples, whereas KRT8 was detected as a potential biomarker in ccRCC.
EpCAM based approaches might miss a high number of CTCs due to low or absent expression of EpCAM in ccRCC, as shown in cell lines as well as in patient samples. We identified the cell-sized based, label independent Parsortix system to be the most effective recovery system for ccRCC CTCs.
循环肿瘤细胞（CTC）分析在多种肿瘤实体中取得了进展。然而，对于透明细胞肾细胞癌（ccRCC）患者的CTC了解甚少。我们研究的目的是为ccRCC中CTC的分离建立一个稳定的基础。
我们比较了不同CTC分离方法在产量和纯度方面的分析性能：基于EpCAM的富集、白细胞去除和基于大小的富集。在ccRCC细胞系以及临床样本中评估了EpCAM和细胞角蛋白8（KRT8）作为CTC表达的生物标志物。
基于EpCAM的方法未能成功分离肿瘤细胞，基于CD45的方法显示出中等回收率。基于细胞大小的Parsortix系统显示出最高的回收率。在大多数细胞系以及临床样本中，EpCAM表达较低或缺失，而KRT8被检测为ccRCC中的一种潜在生物标志物。
如在细胞系和患者样本中所示，由于ccRCC中EpCAM表达较低或缺失，基于EpCAM的方法可能会遗漏大量CTC。我们确定基于细胞大小的、无需标记的Parsortix系统是ccRCC CTC最有效的回收系统。
