Electrophoretic analysis of the cleaved form of serpin, squamous cell carcinoma antigen-1 in normal and malignant squamous epithelial tissues.
The aim of this study was to detect the cleaved form of serine proteinase inhibitor (serpin), squamous cell carcinoma (SCC) antigen-1 in normal and malignant squamous epithelial tissues, which implies the presence of its target proteinase. The cleaved SCC antigen-1 in normal squamous epithelium was identified as a single spot with pI 6.35 and M(r) 40,000 by two-dimensional electrophoresis (2-DE) combined with immunoblotting. Interestingly, the cleaved form showed different biochemical properties in heat stability or immunoreactivity with a monoclonal antibody for SCC antigen (Mab 426) compared to intact SCC antigen-1. Furthermore, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of tissue extracts showed an abundant 40 kDa band of cleaved SCC antigen-1 in tumor tissue compared to normal tissue. Among the potential target proteinase of SCC antigen-1, immunoblotting analyses revealed that cathepsin L2 was remarkably overexpressed in tumor tissue, while cathepsin L was expressed in both normal and tumor tissues. These findings indicate that SCC antigen-1 interacts with specific endogenous proteinases such as cathepsins L and L2 in physiological and pathological states of squamous epithelium.
Nawata
Shugo
S
Department of Reproductive, Pediatric and Infectious Science, University School of Medicine, Ube, Japan. obgyn@po.cc.yamaguchi-u.ac.jp
Nakamura
Kazuyuki
K
Hirakawa
Hiroshi
H
Sueoka
Kotaro
K
Emoto
Tomoko
T
Murakami
Akihiro
A
Umayahara
Kenji
K
Ogata
Hidenobu
H
Suminami
Yoshinori
Y
Numa
Fumitaka
F
Kato
Hiroshi
H
D000951:Antigens, Neoplasm / Q000032:analysis / Q000302:isolation & purification*; D002403:Cathepsins / Q000032:analysis / Q000302:isolation & purification; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D010450:Endopeptidases / Q000032:analysis / Q000302:isolation & purification; D006801:Humans; D015151:Immunoblotting; D018307:Neoplasms, Squamous Cell / Q000737:chemistry* / Q000473:pathology; D015843:Serpins / Q000032:analysis / Q000302:isolation & purification*
D000951:Antigens, Neoplasm; D015843:Serpins; C051072:squamous cell carcinoma-related antigen; D002403:Cathepsins; D010450:Endopeptidases