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Overproduction of urokinase-type plasminogen activator is regulated by phospholipase D- and protein kinase C-dependent pathways in murine mammary adenocarcinoma cells.
Aguirre Ghiso, J A; Alonso, D F; Farías, E F; Bal de Kier Joffé, E.
Affiliation
  • Aguirre Ghiso JA; Research Area, Institute of Oncology Angel H. Roffo, University of Buenos Aires, Argentina. postmast@butnol.fmed.uba.ar
Biochim Biophys Acta ; 1356(2): 171-84, 1997 Apr 24.
Article in En | MEDLINE | ID: mdl-9150275
ABSTRACT
Urokinase-type plasminogen activator (uPA) initiates a proteolytic cascade with which invasive cells eliminate barriers to movement. The signaling pathways regulating uPA production in tumor cells remain unclear. We first studied the effects of n-butanol, a phospholipase D (PLD) and protein kinase C (PKC) inhibitor, on the production of uPA in murine mammary adenocarcinoma cells. Tumor cell monolayers treated during 24 h with 0.3% v/v n-butanol, secreted 45-50% less uPA to the culture medium than control monolayers (P < 0.001) as determined by radial caseinolysis, zymography and western blot. This inhibition occurred also with 5-h treatments and remained up to 5 h after the removal of the alcohol. Treatment with the phorbol ester PMA or with EGF, strongly increased uPA production (P < 0.001). Interestingly, a mild inhibition of uPA production was observed when PMA stimulation was assayed in cotreatments with n-butanol. In contrast EGF was unable to reverse the inhibition induced by n-butanol. H7 significantly inhibited uPA activity (P < 0.001) secreted to the culture media. Furthermore, phosphatidic acid significantly stimulated uPA production meanwhile propranolol, which blocks phosphatidic acid availability, reduced it, suggesting a main regulatory role for this intermediary metabolite. These results suggest for the first time that uPA production is regulated by PLD and PKC signal transduction pathways in murine mammary adenocarcinoma cells.
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Collection: 01-internacional Database: MEDLINE Main subject: Phospholipase D / Protein Kinase C / Urokinase-Type Plasminogen Activator / Adenocarcinoma / Mammary Neoplasms, Experimental Limits: Animals Language: En Journal: Biochim Biophys Acta Year: 1997 Document type: Article Affiliation country: Argentina
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Collection: 01-internacional Database: MEDLINE Main subject: Phospholipase D / Protein Kinase C / Urokinase-Type Plasminogen Activator / Adenocarcinoma / Mammary Neoplasms, Experimental Limits: Animals Language: En Journal: Biochim Biophys Acta Year: 1997 Document type: Article Affiliation country: Argentina