Protein kinase C: a potential pathway of macrophage activation with cisplatin.

Cisplatin (CP) has been reported to activate murine macrophages to tumoricidal state, however, its mechanism of action is not known. In the present study it is reported that the production of: (a) interleukin-1 (IL-1); (b) tumor necrosis factor (TNF); (c) nitric oxide (NO); and (d) macrophage-mediated cytotoxicity by cisplatin-treated bone marrow-derived macrophages were inhibited by PKC inhibitors H-7 and chelerythrine chloride. Also, it was observed that treatment of macrophages with CP resulted in the translocation of PKC from the cytosol to the membrane fraction. These findings suggest the involvement of PKC in the activation of bone marrow-derived macrophages with cisplatin.