4072

EPCAM

DIAR5|EGP-2|EGP314|EGP40|ESA|HNPCC8|KS1/4|KSA|M4S1|MIC18|MK-1|TACSTD1|TROP1;epithelial cell adhesion molecule;EPCAM;epithelial cell adhesion molecule

adenocarcinoma-associated antigen|cell surface glycoprotein Trop-1|epithelial glycoprotein 314|human epithelial glycoprotein-2|major gastrointestinal tumor-associated protein GA733-2|membrane component, chromosome 4, surface marker (35kD glycoprotein)|tum

2p21

protein-coding

Germ cell tumors (GCTs) are thought to develop from totipotent primordial germ cells. Although the epithelial cell adhesion molecule (EPCAM) is expressed on embryonic stem cells as well as different tumor cells, it has not yet been extensively studied in GCTs. We analyzed EPCAM expression by quantitative RT-PCRin 48 fresh-frozen GCT specimens of different histology (10 mature teratoma, MT;6 immature teratoma, IT; 7 dysgerminoma; 6 mixed malignant GCTs; 19 yolk sac tumor, YST) and in the GCT cell lines NCCIT, TE76.T, JAR and 2102Ep, and correlated its expression with AFP and hCG protein levels, histologic differentiation, and clinical follow-up data. EPCAM protein was visualized by immunohistochemistry of selected corresponding paraffin embedded tumor tissues. EPCAM was expressed in malignant but not in benign GCTs irrespective of age, sex, site and clinical stage of tumor (P = 0.001). In primary teratomas, EPCAM expression increased with their grade of immaturity (mean 2(-DeltaCt) values: MT0.23, IT 1.61, P = 0.007) and significantly correlated with serum AFP (P = 0.03)and hCG (P = 0.03) levels in malignant GCTs. Particularly high EPCAM levels werefound in nonseminomatous GCTs such as YSTs (8.49) and choriocarcinoma (13.54). Immunohistochemical analysis verified gene expression data showing a distinct EPCAM staining in YST. Similarly in vitro, highest EPCAM expression was measuredin GCT cell lines comprising yolk sac (2102Ep: 5.59) or choriocarcinoma (JAR: 10.65) components. This first comprehensive analysis of EPCAM in GCTs revealed high EPCAM expression in YSTs and choriocarcinomas. Thus, these nonseminomatous GCTs may be interesting targets for EPCAM immunotherapy, which has to be evaluated in further studies.#CI- Copyright (c) 2012 Wiley Periodicals, Inc.