title: Modulation of urokinase-type plasminogen activator and metalloproteinase activities in cultured mouse mammary-carcinoma cells: enhancement by paclitaxel and inhibition by nocodazole.
abstract: Paclitaxel is a potent anti-tumor drug used in the treatment of breast cancer. It induces de-centralization of the microtubular system in tumor cells, blocking cell division. In the search for dissemination to a secondary site, cancer cells are capable of degrading most components of the extracellular matrix via an extracellular proteolytic cascade, including urokinase-type plasminogen activator (uPA) and the matrix metalloproteinases (MMPs). In the present study, the effects of paclitaxel and nocodazole, 2 drugs known to affect microtubules with opposite mechanisms of action, have been tested for their effect on the secretion of uPA and MMPs in cultures of F3II mouse mammary-tumor cells. Tumor-derived uPA activity significantly increased after pre-treatment of tumor cells for 24 hr with micromolar concentrations of paclitaxel (4 microM), while decreasing after pre-treatment with nocodazole (1 microM). A similar modulation was found for MMP-9 by zymographic analysis. Immunofluorescence and Western-blot analysis confirmed the formation of parallel microtubule fragments in paclitaxel-treated cells and almost complete de-polymerization of microtubules in nocodazole-treated ones. Our data suggest that, through opposite actions on microtubule organization and dynamics, paclitaxel and nocodazole exert inverse modulation of tumor-derived proteolytic activity in mammary tumor cells.
authors.affiliation: Laboratory of Molecular Oncology, Department of Science and Technology, Quilmes National University, Buenos Aires, Argentina.
authors.forename: D F
authors.initials: DF
authors.lastname: Alonso
authors.forename: H G
authors.initials: HG
authors.lastname: Farina
authors.forename: C
authors.initials: C
authors.lastname: Arregui
authors.forename: M A
authors.initials: MA
authors.lastname: Aon
authors.forename: D E
authors.initials: DE
authors.lastname: Gomez
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017364:Collagenases / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D020780:Matrix Metalloproteinase 9; D061965:Matrix Metalloproteinase Inhibitors; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008870:Microtubules / Q000187:drug effects; D015739:Nocodazole / Q000494:pharmacology*; D017239:Paclitaxel / Q000494:pharmacology*; D012636:Secretory Rate / Q000187:drug effects; D014404:Tubulin / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014568:Urokinase-Type Plasminogen Activator / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D061965:Matrix Metalloproteinase Inhibitors; D014404:Tubulin; D014568:Urokinase-Type Plasminogen Activator; D017364:Collagenases; D008666:Metalloendopeptidases; D020780:Matrix Metalloproteinase 9; D017239:Paclitaxel; D015739:Nocodazole