title: Validation of histological diagnostic methods for detecting endothelin B receptor expression.
abstract: Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor prognosis. Recently, it was reported that the endothelin B receptor (ETBR) of tumor endothelial cells prevents antitumor immunity. However, the immuno-histochemistry (IHC) conditions required to detect ETBR expression remain unclear. The aim of the present study was to confirm the appropriate conditions for IHC for ETBR using ETBR cDNA and transfectant cells and to assess ETBR expression in PDAC patients. An ETBR-expressing cell was established as an objective positive control and the detectability of ETBR expression was evaluated using several types of anti-ETBR antibodies. ETBR mRNA expression was then studied. Finally, ETBR expression was examined in human PDAC tissue using IHC. As a result, four different anti-ETBR antibodies recognized the cell surface ETBR appropriately. A non-specific reaction was shown in the detection of ETBR in normal human tissues. ETBR mRNA expression was weakly detected only in the adrenal gland. No biologically significant correlation was observed in the ETBR-IHC of human PDAC sections. In conclusion, it is necessary to perform IHC using an appropriate control to assess the tissue expression of ETBR.
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Fukuda
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsuchikawa
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Fukunaga
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kawase
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Naotake
authors.initials: N
authors.lastname: Homma
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Nakamura
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Shichinohe
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hirano
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000378:metabolism*; D044023:Receptor, Endothelin B / Q000032:analysis / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: D014408:Biomarkers, Tumor; D044023:Receptor, Endothelin B