Increased capacity of lymphocytes to lyse tumor cells in vitro and production of lymphotoxins after cisplatin treatment.

Spleen lymphocytes from C3H/He mice when treated with cisplatin show increased cytostasis and cytotoxicity against Dalton's lymphoma cells in vitro. Cisplatin treatment of splenocytes does not render them cytotoxic/or cytostatic against normal splenocytes. Splenocytes on treatment with cisplatin also produce tumor cell-specific cytotoxic/cytostatic factors (lymphotoxins) which have cytolytic and cytostatic effect on Dalton's lymphoma cells. The increased cytotoxicity of splenocytes on treatment with cisplatin is reversed by the calcium channel blocker nifedipine and the calmodulin antagonist chlorpromazine, suggesting a role of calcium in cisplatin-activated lymphocyte-mediated cytotoxicity.