title: Differences in induction of lysosomal protease activity by protease inhibitors in B16 melanoma cell lines.
abstract: 1. The effects of potent protease inhibitors in vitro (leupeptin, pepstatin and E-64[N-[L-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl]agmatine]) on intracellular cathepsin B (EC 3.4.22.1), hemoglobin (Hb)-hydrolase and acid phosphatase (EC 3.1.3.2) from cultured B16 melanoma variants (B16-F1, F10 and BL6) were studied. 2. E-64 induced all the cultured B16 melanoma variants to decrease the activity of intracellular cathepsin B but did not have this effect with Hb-hydrolase or acid phosphatase. Furthermore, E-64 decreased the activity of cathepsin B in both the lysosomal and cytosol fractions. 3. Leupeptin induced all the cultured B16 melanoma variants to increase the activities of intracellular cathepsin B and Hb-hydrolase but not that of acid phosphatase. An increase in the level of cathepsin B activity was most significant in B16-BL6 followed by F10 and then F1 variants. 4. Leupeptin induced all the cultured B16 melanoma variants to increase the cathepsin B activity in the lysosomal fraction. Our data differed from the results of Tanaka et al. (1981) in that leupeptin induced rat cultured hepatocytes to inhibit the activity of intracellular cathepsin B and increase the Hb-hydrolase activity, especially in the cytosol fraction.
authors.affiliation: Department of Dermatology, Juntendo University, School of Medicine, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakao
authors.forename: Y
authors.initials: Y
authors.lastname: Kurita
authors.forename: R
authors.initials: R
authors.lastname: Tsuboi
authors.forename: K
authors.initials: K
authors.lastname: Takamori
authors.forename: H
authors.initials: H
authors.lastname: Ogawa
mesh_terms: D000135:Acid Phosphatase / Q000096:biosynthesis*; D000818:Animals; D002401:Cathepsin B / Q000096:biosynthesis*; D004790:Enzyme Induction; D007930:Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology*; D008546:Melanoma, Experimental / Q000201:enzymology*; D051379:Mice; D009842:Oligopeptides / Q000494:pharmacology*; D010436:Pepstatins / Q000494:pharmacology*; D010447:Peptide Hydrolases / Q000096:biosynthesis*; D011480:Protease Inhibitors / Q000494:pharmacology*; D013347:Subcellular Fractions / Q000187:drug effects / Q000201:enzymology; D014407:Tumor Cells, Cultured
chemical_list: D007976:Leupeptins; D009842:Oligopeptides; D010436:Pepstatins; D011480:Protease Inhibitors; C014195:Streptomyces pepsin inhibitor; D000135:Acid Phosphatase; D010447:Peptide Hydrolases; C022759:hemoglobin hydrolase; D002401:Cathepsin B; D007930:Leucine; C032854:leupeptin; C024974:E 64; C031375:pepstatin