Cisplatin-induced activation of murine bone marrow-derived macrophages require protein tyrosine phosphorylation.
The aim of the present study is to evaluate the involvement of tyrosine phosphorylation in the signal transduction mechanism of cisplatin-induced macrophage activation in vitro. Stimulation of bone marrow-derived macrophages (BMDM) with cisplatin (CP) resulted in a time- and dose-dependent phosphorylation of several proteins having estimated molecular weights of approximately 18, 20, 21, 30, 33, 35, 39, 41, 44, 58 and 123 kD, detected by immunoblot using anti-phosphotyrosine antibody. CP-induced tyrosine phosphorylation was inhibited by the tyrosine kinase inhibitor genistein. Using this inhibitor, we were able to correlate tyrosine phosphorylation with several functional effects of CP on murine bone marrow-derived macrophages (BMDM). Treatment of macrophages with genistein before incubation with CP completely inhibited the CP-induced tumoricidal activation of macrophages as well as production of TNF and NO, whereas pre-treatment of macrophages with phosphatase inhibitor sodium vanadate upregulated macrophage activation in addition to enhanced protein tyrosine phosphorylation. Taken together, these data suggest that tyrosine phosphorylation play a critical regulatory role in the activation of macrophages with CP.
Shishodia
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School of Biotechnology, Banaras Hindu University, Varanasi, India.
Sodhi
A
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Shrivastava
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D000818:Animals; D002945:Cisplatin / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000494:pharmacology; D008262:Macrophage Activation; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000096:biosynthesis; D019319:Okadaic Acid / Q000494:pharmacology; D010636:Phenols / Q000494:pharmacology; D010744:Phosphoric Monoester Hydrolases / Q000037:antagonists & inhibitors / Q000502:physiology; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors* / Q000502:physiology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D004791:Enzyme Inhibitors; D010636:Phenols; D014409:Tumor Necrosis Factor-alpha; D019319:Okadaic Acid; D009569:Nitric Oxide; C062898:lavendustin A; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D010744:Phosphoric Monoester Hydrolases; D002945:Cisplatin