title: Osteoblast-conditioned media stimulate membrane vesicle shedding in prostate cancer cells.
abstract: Although it has been shown that the cross-talk between osteoblasts and tumor cells stimulates proliferation and invasion of prostate carcinoma (PCa) cells, the molecular mechanisms underlying this event are largely unknown. In this study, we demonstrated that the PCa cells, PC3, derived from bone metastasis, undergo changes of their invasive capability if grown in the presence of osteoblast-derived conditioned media (OBCM). Specifically, they were able to organize tridimensional structures in Matrigel, such as large branching colonies, tube-like structures and clusters of proliferating cells, after treatment. At the ultrastructural level, we observed that PC3 cells grown in the presence of OBCM presented an increment of membrane activity with a blast of shed membrane vesicles from the cell surface. After 6 h of incubation, protein content was approximately 5-fold more elevated in vesicles isolated from PC3 cells cultured in OBCM than in unstimulated cultures. Gelatin zymography of vesicles collected from OBCM-treated PC3 cells showed an increment of lytic bands of MMP family members identified as pro-enzymatic and active forms of gelatinase A (MMP-2) and gelatinase B (MMP-9). By casein-plasminogen zymography, this latter culture also presented an elevated level of high-molecular weight urokinase plasminogen activator (HMW-uPA). Purified vesicles from OBCM-treated PC3 cells incubated with Matrigel cleaved its components more efficiently than vesicles from untreated PC3 cells. Collectively, these findings indicate that osteoblasts produce factor/s able to modify the invasive capability of prostate cancer cells, increasing the amount of shed vesicles and of their associated lytic enzymes.
authors.affiliation: Department of Experimental Medicine, University of L'Aquila, 67100 L'Aquila, Italy.
authors.forename: Danilo
authors.initials: D
authors.lastname: Millimaggi
authors.forename: Claudio
authors.initials: C
authors.lastname: Festuccia
authors.forename: Adriano
authors.initials: A
authors.lastname: Angelucci
authors.forename: Sandra
authors.initials: S
authors.lastname: D'Ascenzo
authors.forename: Nadia
authors.initials: N
authors.lastname: Rucci
authors.forename: Silvio
authors.initials: S
authors.lastname: Flati
authors.forename: Mauro
authors.initials: M
authors.lastname: Bologna
authors.forename: Anna
authors.initials: A
authors.lastname: Teti
authors.forename: Antonio
authors.initials: A
authors.lastname: Pavan
authors.forename: Vincenza
authors.initials: V
authors.lastname: Dolo
mesh_terms: D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D017077:Culture Media, Conditioned / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D004792:Enzyme Precursors / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D009361:Neoplasm Invasiveness; D010006:Osteoblasts / Q000166:cytology / Q000502:physiology*; D011471:Prostatic Neoplasms / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism; D022161:Transport Vesicles / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: D017077:Culture Media, Conditioned; D004792:Enzyme Precursors; D008565:Membrane Proteins; D019715:Tissue Inhibitor of Metalloproteinase-1; D014568:Urokinase-Type Plasminogen Activator; D020782:Matrix Metalloproteinases