Author/Editor		Heidtmann, Hans-Heinrich; Salge, Ursula; Abrahamson, Magnus; Benčina, Mojca; Kastelic, Lili; Kopitar-Jerala, Nataša; Turk, Vito; Lah, Tamara T
Title		Cathepsin B and cysteine proteinase inhibitors in human lung cancer cell lines
Type		članek
Source		Clin Exp Metastasis
Vol. and No.		Letnik 15, št. 4
Publication year		1997
Volume		str. 368-81
Language		eng
Abstract		Cell lines derived from human squamous cell (EPCL), large cell (LCLC), and small cell lung cancer (SCLC) lines were investigated for the expression of cathepsin B (Cat B) and cysteine proteinase inhibitors (CPIs). The EPLC and LCLC lines expressed 5- to 50-fold more Cat B activity and contained more mature Cat B of M, 27-29 kDa (>2.5 micro g/mg total protein) than the SCLC lines (<1.0 micro/mb total protein). The LPLC lines also secreted the highest amounts of Cat B precursor of M, about 46 kDa. Inhibitory activites against Cat B and papain were associated with high molecular mass (HMM) and low molecular mass (LMM) inhibitory proteins, both in cell extracts and in media. About 75% of the inhibitory activity was associated with HMM inhibitors, the majority of which were kininogens (Mr>-67 kDa). The LMM inhibitors of Mr 10-15 kDa were cystatin C and stefins A and B, which were quantitated by ELISA: stefins A and B were present in cell extracts and medium in similar concentrations (5-200 ng/10 6 cells), while 80-99% of the cystatin C was released in the medium (10-195 ng/10 6 cells). Phorbol ester (PMA), which induces proteinkinase C mediated signal transduction and enhances cellular differentiation in many non-small cell lung cancer (NSCLC) cell lines, increased intracellular Cat B activity and Cat B protein as well as its secretion in some cell lines but not in others, regadless of their histological type. PMA significantly (P < 0.049) decreased intracellular stefin A concentrations in two EPLC lines and non-significantly in two LCLC lines. PMA decreased secretion of stefin A in all EPLC lines, but not in LCLC lines, while IGF-I significantly increased stefin B secretion in both SCLC lines.(Abstract tuncated at 2000 characters.)
Descriptors		LUNG NEOPLASMS CATHEPSIN B CYSTEINE PROTEINASE INHIBITORS CELL LINE, TRANSFORMED CARCINOGENS PAPAIN KININOGENS TETRADECANOYLPHORBOL ACETATE INSULIN-LIKE GROWTH FACTOR I ELECTROPHORESIS, POLYACRYLAMIDE GEL MOLECULAR WEIGHT ISOELECTRIC FOCUSING IMMUNOBLOTTING ENZYME-LINKED IMMUNOSORBENT ASSAY PROTEIN KINASES CARCINOMA, LARGE CELL CARCINOMA, NON-SMALL-CELL LUNG