Macrophage Cytotoxicity against Murine Meth A Sarcoma Involves Nitric Oxide-Mediated Apoptosis

We have studied the cytotoxic effect of stimulated macrophages on Meth A tumor cellsin vitro.When stimulated with interferon-γ and soluble β-1,3-D-glucan, macrophages exerted cytotoxicity towards syngeneic Meth A tumor cells. This cytotoxicity was associated with a high level of nitric oxide production. Both cell death and nitric oxide production were significantly inhibited by the addition of aminoguanidine, a specific inhibitor of inducible nitric oxide synthase (iNOS), to the culture medium. The cytotoxic effect was accompanied by internucleosomal cleavage of DNA as shown by electrophoresis and DNA fragmentation assay.