Details

Autor(en) / Beteiligte

• Lanzi, Cinzia
• Gambetta, Romolo Achille
• Perego, Paola
• Banfi, Patrizia
• Franzi, Aimarita
• Guazzoni, Lorena
• Zunino, Franco

Titel

Protein kinase C activation by anthracyclines in swiss 3T3 cells

Ist Teil von

• International journal of cancer, 1991-01, Vol.47 (1), p.136-142

Ort / Verlag

New York: Wiley Subscription Services, Inc., A Wiley Company

Erscheinungsjahr

1991

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• The effects of the anti‐cancer anthracyclines doxorubicin and daunorubicin on the activity of protein kinase C (PKC) were examined in intact Swiss 3T3 cells. The 2 drugs stimulated the phosphorylation of an 80K phosphoprotein found to be identical to that generated in response to the PKC activator 12‐O‐tetradecanoylphorbol‐13‐acetate as indicated by gel electrophoresis and peptide mapping. The effect of doxorubicin was dose‐dependent in the range 10−5 to 10−3 M and was not associated with a detectable translocation of PKC activity from cytosol to the cell membrane. Doxorubicin and daunorubicin were found to increase the incorporation of phosphate into phosphatide acid, phosphatidylinositol 4‐monophosphate and phosphatidyl inositol 4,5‐bisphosphate. In addition, the anthracyclines induced a rise in inositol phosphates, thus indicating a stimulation of the breakdown of phosphoinositides. These data are consistent with an indirect mechanism of PKC activation by anthracyclines. We propose that diacylglycerol, which is derived from the hydrolysis of phospholipids, (including the phosphoinositides), by activation of phospholipases, could mediate PKC activation. The described effects, involving cell‐signal‐transducing pathways, emphasize a new aspect of the cellular actions of these anti‐tumor agents.