RT Journal Article
SR Electronic
T1 Expression of cathepsins B, D and K in thymic epithelial tumours
JF Journal of Clinical Pathology
JO J Clin Pathol
FD BMJ Publishing Group Ltd and Association of Clinical Pathologists
SP 84
OP 90
DO 10.1136/jclinpath-2020-206551
VO 74
IS 2
A1 Naoko Yamaguchi
A1 Utano Tomaru
A1 Takayuki Kiuchi
A1 Akihiro Ishizu
A1 Takahiro Deguchi
A1 Noriyuki Otsuka
A1 Satoshi Tanaka
A1 Katsuji Marukawa
A1 Yoshihiro Matsuno
A1 Masanobu Kitagawa
A1 Masanori Kasahara
YR 2021
UL http://jcp.bmj.com/content/74/2/84.abstract
AB Aim Cathepsins are proteases that regulate a wide range of physiological processes, including protein turnover, cell signalling and antigen presentation. Recent studies have shown that cathepsins are highly upregulated in many types of tumours. Of the 15 cathepsins in humans, cathepsins V and S are abundantly expressed in the thymus, and we previously showed that the immunostaining of these cathepsins could serve as diagnostic markers for thymic epithelial tumours. However, little is known about the expression of other cathepsins in thymic epithelial tumours. To determine the diagnostic implications of cathepsins, we performed immunohistochemical analysis of cathepsin B (CTB), cathepsin D (CTD) and cathepsin K (CTK), all of which have been reported to correlate with the progression of squamous cell carcinoma.Methods The association between cathepsin expression and clinicopathological features was evaluated in 122 cases of thymoma and thymic carcinoma.Results CTB and CTD were frequently expressed in type A and type AB thymomas. In contrast, CTB and CTD were significantly less common in type B thymomas than in type A or AB thymomas. In type AB thymomas, the expression of CTB correlated with histological features, and was found predominantly in the type A component. Notably, CTK was expressed most commonly in thymic carcinomas, and patients who died of the disease showed increased expression of CTK.Conclusions The expression of CTB and CTD correlated with the histological subtype of thymoma. In addition, the expression of CTK appears to be useful for the diagnosis of thymic carcinomas and as a prognostic marker.