Soluble EpCAM levels in ascites correlate with positive cytology and neutralize catumaxomab activity in vitro

BMC Cancer

Research Article

Guenther Gastl¹  Thomas Buratti²  Agnieszka Martowicz³  Dominic Fong⁴  Andreas Seeber⁵  Gerold Untergasser⁵  Gilbert Spizzo⁶  Peter Obrist⁷ 

[1]Department of Hematology and Oncology, Medical University of Innsbruck, Innsbruck, Austria

[2]Department of Internal Medicine, Hospital of Merano, Merano, Italy

[3]Experimental Oncogenomics, Tyrolean Cancer Research Institute, Innsbruck, Austria

[4]Division of Vascular Biology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden

[5]Experimental Oncogenomics, Tyrolean Cancer Research Institute, Innsbruck, Austria

[6]Hemato-Oncological Day Hospital, Hospital of Merano, Merano, Italy

[7]Experimental Oncogenomics, Tyrolean Cancer Research Institute, Innsbruck, Austria

[8]Oncotyrol – Center for Personalized Cancer Medicine, Innsbruck, Austria

[9]Department of Hematology and Oncology, Medical University of Innsbruck, Innsbruck, Austria

[10]Experimental Oncogenomics, Tyrolean Cancer Research Institute, Innsbruck, Austria

[11]Oncotyrol – Center for Personalized Cancer Medicine, Innsbruck, Austria

[12]Hemato-Oncological Day Hospital, Hospital of Merano, Merano, Italy

[13]Pathology Laboratory, Hospital of Zams, Zams, Austria

关键词: Ascites;    Catumaxomab;    Cytology;    Elisa;    Liver cirrhosis;    Peritoneal carcinomatosis;    Soluble EpCAM;   

DOI  :  10.1186/s12885-015-1371-1

 received in 2014-05-21, accepted in 2015-04-27,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundEpCAM is highly expressed on membrane of epithelial tumor cells and has been detected as soluble/secreted (sEpCAM) in serum of cancer patients. In this study we established an ELISA for in vitro diagnostics to measure sEpCAM concentrations in ascites. Moreover, we evaluated the influence of sEpCAM levels on catumaxomab (antibody) - dependent cellular cytotoxicity (ADCC).MethodsAscites specimens from cancer patients with positive (C+, n = 49) and negative (C-, n = 22) cytology and ascites of patients with liver cirrhosis (LC, n = 31) were collected. All cell-free plasma samples were analyzed for sEpCAM levels with a sandwich ELISA system established and validated by a human recombinant EpCAM standard for measurements in ascites as biological matrix. In addition, we evaluated effects of different sEpCAM concentrations on catumaxomab-dependent cell-mediated cytotoxicity (ADCC) with human peripheral blood mononuclear cells (PBMNCs) and human tumor cells.ResultsOur ELISA showed a high specificity for secreted EpCAM as determined by control HEK293FT cell lines stably expressing intracellular (EpICD), extracellular (EpEX) and the full-length protein (EpCAM) as fusion proteins. The lower limit of quantification was 200 pg/mL and the linear quantification range up to 5,000 pg/mL in ascites as biological matrix. Significant levels of sEpCAM were found in 39% of C+, 14% of C- and 13% of LC ascites samples. Higher concentrations of sEpCAM were detectable in C+ (mean: 1,015 pg/mL) than in C- (mean: 449 pg/mL; p = 0.04) or LC (mean: 326 pg/mL; p = 0.01). Soluble EpCAM concentration of 1 ng/mL significantly inhibited ADCC of PBMNCs on EpCAM overexpressing target cells.ConclusionElevated concentrations of sEpCAM can be found in a subgroup of C+ and also in a small group of C- patients. We consider that sEpCAM levels in different tumor entities and individual patients should be evaluated prior to applying anti-EpCAM antibody-based cancer therapies, since sEpCAM neutralizes catumaxomab activity, making therapy less efficient.

【 授权许可】

Unknown   
© Seeber et al.; licensee BioMed Central. 2015. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.