title: Expression of cathepsins V and S in thymic epithelial tumors.
abstract: Cathepsins are a group of proteolytic enzymes of the endosomal/lysosomal pathway involved in the thymic development of T cells restricted by major histocompatibility complex class II molecules. In the normal thymus, cathepsin V (CTV) and cathepsin S (CTS) are expressed in cortical and medullary epithelial cells, respectively. To investigate whether cathepsins could serve as a diagnostic marker, we performed immunohistochemical analysis for CTV and CTS in 77 cases of thymic epithelial tumors. Almost all cases (59/60) of thymoma expressed CTV, whereas 28 of 60 cases of thymoma expressed CTS. Notably, CTS was expressed in most cases of type A and type AB thymomas, but not in type B thymoma. The expression of cathepsins in type AB thymoma showed a clear correlation with histologic features; CTV was found predominantly in the type B component, and CTS was frequently expressed in the type A component. In thymic carcinoma, CTV was expressed in less than half cases (7/17), and the ratio of CTS-positive cases was equivalent to that of thymoma (8/17). Cases of CTV-negative thymic carcinoma tended to have a higher incidence of recurrence than did CTV-positive cases. Although further studies with a larger number of cases are required to confirm the utility of cathepsin immunostaining, CTV and CTS appear to serve as auxiliary diagnostic and/or prognostic markers in thymic epithelial tumors.
authors: Department of Pathology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.
authors: Shizuka
authors: S
authors: Kiuchi
authors: Department of Pathology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan. Electronic address: tomaruu@med.hokudai.ac.jp.
authors: Utano
authors: U
authors: Tomaru
authors: Faculty of Health Sciences, Hokkaido University, Sapporo 060-0812, Japan.
authors: Akihiro
authors: A
authors: Ishizu
authors: Department of Diagnostic Pathology, KKR Sapporo Medical Center, Sapporo 062-0931, Japan.
authors: Makoto
authors: M
authors: Imagawa
authors: Department of Pathology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.
authors: Takayuki
authors: T
authors: Kiuchi
authors: Department of Diagnostic Pathology, KKR Sapporo Medical Center, Sapporo 062-0931, Japan.
authors: Sari
authors: S
authors: Iwasaki
authors: Department of Diagnostic Pathology, KKR Sapporo Medical Center, Sapporo 062-0931, Japan.
authors: Akira
authors: A
authors: Suzuki
authors: Department of Pathology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.
authors: Noriyuki
authors: N
authors: Otsuka
authors: Department of Surgical Pathology, Hokkaido University Hospital, Sapporo 060-8648, Japan.
authors: Takahiro
authors: T
authors: Deguchi
authors: Department of Surgical Pathology, Hokkaido University Hospital, Sapporo 060-8648, Japan.
authors: Tomohiro
authors: T
authors: Shimizu
authors: Department of Surgical Pathology, Hokkaido University Hospital, Sapporo 060-8648, Japan.
authors: Katsuji
authors: K
authors: Marukawa
authors: Department of Surgical Pathology, Hokkaido University Hospital, Sapporo 060-8648, Japan.
authors: Yoshihiro
authors: Y
authors: Matsuno
authors: Department of Pathology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan.
authors: Masanori
authors: M
authors: Kasahara
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001706:Biopsy; D002403:Cathepsins / Q000032:analysis*; D003546:Cysteine Endopeptidases / Q000032:analysis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009375:Neoplasms, Glandular and Epithelial / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D011237:Predictive Value of Tests; D013945:Thymoma / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D013953:Thymus Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C028217:cathepsin S; C117627:CTSV protein, human
keywords: Cathepsin S; Cathepsin V; Diagnostic marker; Thymic carcinoma; Thymoma