title: Chondroitin sulfate proteoglycan CSPG4 as a novel hypoxia-sensitive marker in pancreatic tumors.
abstract: CSPG4 marks pericytes, undifferentiated precursors and tumor cells. We assessed whether the shed ectodomain of CSPG4 (sCSPG4) might circulate and reflect potential changes in CSPG4 tissue expression (pCSPG4) due to desmoplastic and malignant aberrations occurring in pancreatic tumors. Serum sCSPG4 was measured using ELISA in test (n = 83) and validation (n = 221) cohorts comprising donors (n = 11+26) and patients with chronic pancreatitis (n = 11+20) or neoplasms: benign (serous cystadenoma SCA, n = 13+20), premalignant (intraductal dysplastic IPMNs, n = 9+55), and malignant (IPMN-associated invasive carcinomas, n = 4+14; ductal adenocarcinomas, n = 35+86). Pancreatic pCSPG4 expression was evaluated using qRT-PCR (n = 139), western blot analysis and immunohistochemistry. sCSPG4 was found in circulation, but its level was significantly lower in pancreatic patients than in donors. Selective maintenance was observed in advanced IPMNs and PDACs and showed a nodal association while lacking prognostic relevance. Pancreatic pCSPG4 expression was preserved or elevated, whereby neoplastic cells lacked pCSPG4 or tended to overexpress without shedding. Extreme pancreatic overexpression, membranous exposure and tissue(high)/sera(low)-discordance highlighted stroma-poor benign cystic neoplasm. SCA is known to display hypoxic markers and coincide with von-Hippel-Lindau and Peutz-Jeghers syndromes, in which pVHL and LBK1 mutations affect hypoxic signaling pathways. In vitro testing confined pCSPG4 overexpression to normal mesenchymal but not epithelial cells, and a third of tested carcinoma cell lines; however, only the latter showed pCSPG4-responsiveness to chronic hypoxia. siRNA-based knockdowns failed to reduce the malignant potential of either normoxic or hypoxic cells. Thus, overexpression of the newly established conditional hypoxic indicator, CSPG4, is apparently non-pathogenic in pancreatic malignancies but might mark distinct epithelial lineage and contribute to cell polarity disorders. Surficial retention on tumor cells renders CSPG4 an attractive therapeutic target. Systemic 'drop and restoration' alterations accompanying IPMN and PDAC progression indicate that the interference of pancreatic diseases with local and remote shedding/release of sCSPG4 into circulation deserves broad diagnostic exploration.
authors.affiliation: European Pancreas Centre, Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Shereen
authors.initials: S
authors.lastname: Keleg
authors.affiliation: European Pancreas Centre, Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Alexandr
authors.initials: A
authors.lastname: Titov
authors.affiliation: European Pancreas Centre, Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Anette
authors.initials: A
authors.lastname: Heller
authors.affiliation: Institute of Immunology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Giese
authors.affiliation: European Pancreas Centre, Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Christine
authors.initials: C
authors.lastname: Tjaden
authors.affiliation: European Pancreas Centre, Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Sufian S
authors.initials: SS
authors.lastname: Ahmad
authors.affiliation: Institute of Pathology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Matthias M
authors.initials: MM
authors.lastname: Gaida
authors.affiliation: Department of Functional Genomics, German Cancer Research Centre, Heidelberg, Germany.
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Bauer
authors.affiliation: European Pancreas Centre, Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Werner
authors.affiliation: European Pancreas Centre, Department of General, Visceral and Transplantation Surgery, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Nathalia A
authors.initials: NA
authors.lastname: Giese
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002291:Carcinoma, Papillary / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011508:Chondroitin Sulfate Proteoglycans / Q000235:genetics / Q000378:metabolism*; D018293:Cystadenoma, Serous / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D005500:Follow-Up Studies; D006801:Humans; D000860:Hypoxia / Q000235:genetics / Q000473:pathology*; D007124:Immunoenzyme Techniques; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009367:Neoplasm Staging; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D046888:Tissue Array Analysis; D014407:Tumor Cells, Cultured; D055815:Young Adult; D000099216:Chondroitin Sulfate Proteoglycan 4
chemical_list: D014408:Biomarkers, Tumor; D011508:Chondroitin Sulfate Proteoglycans; D008565:Membrane Proteins; D012333:RNA, Messenger; C101390:CSPG4 protein, human; D000099216:Chondroitin Sulfate Proteoglycan 4