title: Differential detection of cytoplasmic Wilms tumor 1 expression by immunohistochemistry, western blotting and mRNA quantification.
abstract: Wilms tumor 1 (WT1) is considered to be a promising target of cancer treatment because it has been reported to be frequently expressed at high levels in various malignancies. Although WT1-targeted cancer treatment has been initiated, conclusive detection methods for WT1 are not established. The present study aimed to consolidate immunohistochemistry for WT1 with statistical basis. Transfected cells with forced WT1 expression yielded specific western blot bands and nuclear immunostaining; cytoplasmic immunostaining was not specifically recognized. Immunohistochemistry, western blotting, and quantitative reverse transcriptase-polymerase chain reaction were performed in 35 human cell lines using multiple WT1 antibodies and their results were quantified. Relationships among the quantified results were statistically analyzed; the nuclear immunostaining positively correlated with western blot bands and mRNA expression levels, whereas cytoplasmic immunostaining did not. These results indicate that nuclear immunostaining reflects WT1 expression but cytoplasmic immunostaining does not. The nuclear immunostaining was barely (3/541) observed in primary cancer of esophagus, bile duct, pancreas and lung. Although the present study has some limitations, the results indicate that the cytoplasmic immunostaining does not correlate with actual WT1 expression and prompts researchers to carefully evaluate target molecule expression in treatment of cancer.
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Maki
authors.affiliation: Department of Oncology, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852‑8523, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ikeda
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: Aki
authors.initials: A
authors.lastname: Kuroda
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kyogoku
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Yamamura
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Tabata
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Abiko
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Tsuchikawa
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Hida
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Shichinohe
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tanaka
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido 060-8638, Japan.
authors.forename: Kichizo
authors.initials: K
authors.lastname: Kaga
authors.affiliation: Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Hokkaido 060‑8648, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Hatanaka
authors.affiliation: Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Hokkaido 060‑8648, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsuno
authors.affiliation: Department of Immuno-gene Therapy, Mie University Graduate School of Medicine, Mie 514-8507, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Imai
authors.affiliation: Department of Gastroenterological Surgery II, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-8638, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hirano
mesh_terms: D014408:Biomarkers, Tumor / Q000096:biosynthesis / Q000302:isolation & purification*; D045744:Cell Line, Tumor; D003593:Cytoplasm / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D009369:Neoplasms / Q000235:genetics* / Q000473:pathology; D012333:RNA, Messenger / Q000302:isolation & purification*; D025721:WT1 Proteins / Q000096:biosynthesis / Q000302:isolation & purification*
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D025721:WT1 Proteins; C583751:WT1 protein, human