journal contribution
posted on 2023-03-31, 17:13 authored by Paulina Nastały, Christian Ruf, Pascal Becker, Natalia Bednarz-Knoll, Małgorzata Stoupiec, Refik Kavsur, Hendrik Isbarn, Cord Matthies, Walter Wagner, Dirk Höppner, Margit Fisch, Carsten Bokemeyer, Sascha Ahyai, Friedemann Honecker, Sabine Riethdorf, Klaus Pantel <p>PDF file - 209KB, Positivity for SALL4, OCT3/4, keratins, EpCAM and Cellsearch(registered trademark) assay in control cell lines. A, Double fluorescence staining for SALL4 (green) / keratins (orange) and OCT3/4 (green) / EpCAM (orange) counterstained with DAPI (blue) to visualize cells' nuclei in 4 different germ cell tumor cell lines (magnification: 400x). Scale bar, 50 microm. B, Representation of the staining of tumor cells from 4 different germ cell tumor cell lines spiked into blood of healthy donors using the Cellsearch(registered trademark) assay. C, Representative images of primary testicular germ cell tumor samples positive for SALL4, OCT3/4, keratins and EpCAM immunohistochemical staining counterstained with Hematoxylin to visualize cells' nuclei (magnification - 400x, scale bar - 50 microm). (CK, cytokeratin. PE, phycoerythrin. APC, allophycocyanin. DAPI, 4′,6-diamidino-2-phenylindole). D, Dot-like pattern keratin (orange) staining in TCam-2 and NT2 cell lines, counterstained with DAPI (blue) to visualize cells' nuclei (magnification: 1000x). Scale bar, 20 microm.</p>
History
ARTICLE ABSTRACT
Purpose: Germ cell tumors (GCTs) represent the most frequent malignancies among young men, but little is known about circulating tumor cells (CTCs) in these tumors. Considering their heterogeneity, CTCs were investigated using two independent assays targeting germ cell tumor and epithelial cell–specific markers, and results were correlated with disease stage, histology, and serum tumor markers.Experimental Design: CTCs were enriched from peripheral blood (n = 143 patients) and testicular vein blood (TVB, n = 19 patients) using Ficoll density gradient centrifugation. For CTC detection, a combination of germ cell tumor (anti-SALL4, anti-OCT3/4) and epithelial cell–specific (anti-keratin, anti-EpCAM) antibodies was used. In parallel, 122 corresponding peripheral blood samples were analyzed using the CellSearch system.Results: In total, CTCs were detected in 25 of 143 (17.5%) peripheral blood samples, whereas only 11.5% of patients were CTC-positive when considering exclusively the CellSearch assay. The presence of CTCs in peripheral blood correlated with clinical stage (P < 0.001) with 41% of CTC positivity in patients with metastasized tumors and 100% in patients with relapsed and chemotherapy-refractory disease. Histologically, CTC-positive patients suffered more frequently from nonseminomatous primary tumors (P < 0.001), with higher percentage of yolk sac (P < 0.001) and teratoma (P = 0.004) components. Furthermore, CTC detection was associated with elevated serum levels of α-fetoprotein (AFP; P = 0.025), β-human chorionic gonadotropin (βHCG; P = 0.002), and lactate dehydrogenase (LDH; P = 0.002). Incidence and numbers of CTCs in TVB were much higher than in peripheral blood.Conclusions: The inclusion of germ cell tumor–specific markers improves CTC detection in GCTs. CTCs occur frequently in patients with more aggressive disease, and there is a gradient of CTCs with decreasing numbers from the tumor-draining vein to the periphery. Clin Cancer Res; 20(14); 3830–41. ©2014 AACR.
