Cysteine proteinase cathepsin H in tumours and sera of lung cancer patients: relation to prognosis and cigarette smoking.
In order to evaluate the role of cysteine peptidase cathepsin H (Cath H) in human lung cancer its protein levels were determined in 148 pairs of lung tumour tissue and adjacent non-tumourous lung parenchyma using the enzyme-linked immunosorbent assay technique. Additionally, Cath H levels were determined in sera of 171 patients with malignant tumours, 34 patients with benign lung diseases and 47 healthy controls. The median level of Cath H in tumour tissue was 0.64 times that in the corresponding lung parenchyma. Relating tumour levels with histological type we found higher Cath H levels in small-cell and adenocarcinomas and lower levels in squamous cell carcinoma, large-cell carcinoma and secondary tumours. A significant difference in Cath H level between lung tumour tissue and non-tumourous lung parenchyma was associated with the group of cigarette smokers (156 vs 263 ng mg(-1) protein, P < 0.001). For this group of patients Cath H tumour levels correlated with the survival rate, while for the entire patient population this was not the case. Smokers with high tumour levels of Cath H experienced poor survival. Cath H was significantly higher in sera of patients with malignant and benign lung diseases than in control sera (P < 0.001). The increase was significant for all histological types, being the highest in small-cell and squamous cell carcinomas. Our study reveals that in lung tumours there is different behaviour of Cath H compared with other cysteine peptidases, e.g. cathepsin B and cathepsin L. Variations between tissue and serum levels of Cath H indicate either reduced expression or enhanced secretion of this enzyme in lung tumours.
Schweiger
A
A
Jozef Stefan Institute, Department of Biochemistry and Molecular Biology, Ljubljana, Slovenia.
Staib
A
A
Werle
B
B
Krasovec
M
M
Lah
T T
TT
Ebert
W
W
Turk
V
V
Kos
J
J
D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology*; D056655:Cathepsin H; D002403:Cathepsins / Q000097:blood / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000097:blood / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology*; D011379:Prognosis; D012907:Smoking / Q000378:metabolism*; D016019:Survival Analysis
D002403:Cathepsins; D003546:Cysteine Endopeptidases; C534126:CTSH protein, human; D056655:Cathepsin H