title: Modulation of vesicle shedding in 8701 BC human breast carcinoma cells.
abstract: Vesicles, shed in the extracellular medium by several kinds of normal and tumoral cells, are known to play important roles in cell-cell and cell-matrix interactions and to participate in mechanisms by which tumoral cells acquire metastatic capability and evade immune surveillance. Regulation of the shedding phenomenon and molecular mechanisms involved in extracellular vesicle production are not known and are the subject of this investigation. Fetal calf serum stimulated shedding short after its addition and its stimulatory effect was dose dependent. This effect was reduced after gelatin-Sepharose adsorption indicating a possible involvement of gelatinases on its stimulatory effect. This conclusion was confirmed by the inhibitory effect of bathophenanthroline. Shedding of membrane vesicles decreased after treatment with all trans retinoic acid, a molecule known for its capability to induce cell differentiation. Brefeldin A, an inhibitor of intracellular vesicle movements, and methylamine, an inhibitor of exocytosis, did not abolish shedding. Quercetin, an inhibitor of phosphatidyl inositol 4 kinase and 1,4 phosphatidyl inositol 5 kinase, and 8-Cl-cAMP, a site selective cAMP analogous which induces growth inhibition and differentiation, significantly decreased the amount of shed vesicles.
authors.affiliation: Department of Cellular and Development Biology, University of Palermo, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Cassarà
authors.forename: A
authors.initials: A
authors.lastname: Ginestra
authors.forename: V
authors.initials: V
authors.lastname: Dolo
authors.forename: M
authors.initials: M
authors.lastname: Miele
authors.forename: G
authors.initials: G
authors.lastname: Caruso
authors.forename: G
authors.initials: G
authors.lastname: Lucania
authors.forename: M L
authors.initials: ML
authors.lastname: Vittorelli
mesh_terms: D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D001943:Breast Neoplasms / Q000503:physiopathology / Q000648:ultrastructure*; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D002462:Cell Membrane / Q000648:ultrastructure; D005109:Extracellular Matrix / Q000648:ultrastructure; D005260:Female; D006801:Humans; D008854:Microscopy, Electron; D009361:Neoplasm Invasiveness / Q000473:pathology / Q000503:physiopathology; D010741:Phospholipases A / Q000494:pharmacology; D011794:Quercetin / Q000494:pharmacology; D015290:Second Messenger Systems; D015398:Signal Transduction; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D015124:8-Bromo Cyclic Adenosine Monophosphate; D014212:Tretinoin; D011794:Quercetin; C044258:8-chloro-cyclic adenosine monophosphate; D010741:Phospholipases A