title: Cathepsin S in tumours, regional lymph nodes and sera of patients with lung cancer: relation to prognosis.
abstract: Cysteine proteinase cathepsin S (Cat S) is expressed mainly in lymphatic tissues and has been characterised as a key enzyme in major histocompatibility complex class II (MHC-II) mediated antigen presentation. Cat S has been measured in tissue cytosols of lung parenchyma, lung tumours and lymph nodes and in sera of patients with lung tumours and of healthy controls, by specific enzyme-linked immunosorbent assay (ELISA). A difference in Cat S level was found between tumour and adjacent control tissue cytosols of 60 lung cancer patients (median 4.3 vs. 2.8 ng mg(-1) protein). In lymph nodes obtained from 24 patients of the same group, the level of Cat S was significantly higher than in tumours or lung parenchyma (P< 0.001). Additionally, significantly higher levels were found in non-infiltrated than in infiltrated lymph nodes (median 16.6 vs 7.5 ng mg(-1) protein). Patients with low levels of Cat S in tumours and lung parenchyma exhibited a significantly higher risk of death than those with high levels of Cat S (P = 0.025 - tumours; P = 0.02 - parenchyma). Immunohistochemical analysis (IHA) of lung parenchyma revealed a staining reaction in alveolar type II cells, macrophages and bronchial epithelial cells. In regional lymph node tissue, strong staining of Cat S was found in lymphocytes and histiocytes. Nevertheless, Cat S was detected also in tumour cells, independently of their origin. Our results provide evidence that Cat S may be involved in malignant progression. Its role, however, differs from that of the related Cats B and L and could be associated with the immune response rather than with remodelling of extracellular matrix.
authors.affiliation: Department of Biochemistry and Molecular Biology, Jozef Stefan Institute, Jamova 39, Ljubljana, SI-1000, Slovenia.
authors.forename: J
authors.initials: J
authors.lastname: Kos
authors.forename: A
authors.initials: A
authors.lastname: Sekirnik
authors.forename: G
authors.initials: G
authors.lastname: Kopitar
authors.forename: N
authors.initials: N
authors.lastname: Cimerman
authors.forename: K
authors.initials: K
authors.lastname: Kayser
authors.forename: A
authors.initials: A
authors.lastname: Stremmer
authors.forename: W
authors.initials: W
authors.lastname: Fiehn
authors.forename: B
authors.initials: B
authors.lastname: Werle
mesh_terms: D000918:Antibody Specificity; D002403:Cathepsins / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000201:enzymology* / Q000401:mortality; D008198:Lymph Nodes / Q000201:enzymology*; D011379:Prognosis
chemical_list: D002403:Cathepsins; C028217:cathepsin S