J Cancer 2016; 7(14):2018-2027. doi:10.7150/jca.15864 This issue
1. Division of Cardiac Surgery, University Hospital Basel, Basel, Switzerland;
2. Institute of Surgical Pathology, University Medical Center Freiburg, Germany;
3. Institute of Molecular Medicine and Cell Research, University of Freiburg, Germany;
4. present address: Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Allianz, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany;
5. Department of Hematology and Oncology, University Medical Center Freiburg, Germany;
6. Clinic for General and Visceral Surgery, University Medical Center Freiburg, Germany;
7. Clinic for Surgery, University Clinic Schleswig-Holstein Campus Lübeck, Germany;
8. BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany;
9. Comprehensive Cancer Center Freiburg, Germany;
10. German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Heidelberg, German.
Proteins of the pregnancy specific β-1 glycoprotein (PSG) family are renowned for their elevated expression during pregnancy. Only few reports have investigated their expression in adenocarcinomas. We studied the expression of PSG1 in pancreatic adenocarcinoma (PDAC). In a cohort of 104 patient samples, immunohistochemical analysis determined PSG1 expression in every specimen. PSG1 was found at apical and cytoplasmic localization or solely at cytoplasmic localization, with the latter case being correlated to shortened median survival (25 vs 11 months, logrank p-value < 0.001). At the same time, enzyme linked immunosorbent assay (ELISA) did not detect elevated PSG1 levels in the plasma of PDAC patients as opposed to the plasma of healthy, non-pregnant control individuals. We also probed the impact of PSG1 expression in a murine tumor model system, using subcutaneous injection of Colo-26 cells into immunocompetent BALB/c mice. Here, tumor growth was not affected by the expression of human PSG1. Our study reaffirms interest into the tumor-contextual biology of PSG proteins.
Keywords: Pregnancy Specific β-1 Glycoprotein, Schwangerschaftsprotein, Immunohistochemistry, Subcellular localization.