INHIBITION OF LUNG AND LIVER-TUMOR COLONIES IN MICE PRETREATED WITH SURAMIN

The effect of suramin on B16F10 melanoma lung colonies and M5076 retic ulosarcoma liver metastasis formation was evaluated in C57B1/6 female mice. Single i.v. doses of 200 mg/kg suramin given 48 and 24 h prior t o tumor cell injection significantly inhibited metastasis formation in both models, whereas the same treatment administered 24 h after cell injection was ineffective. A dose-response experiment in the B16F10 me lanoma model showed that inhibition of lung colony formation was still significant with 50 mg/kg pretreatment, whereas a borderline effect w as observed at 10 mg/kg. At the effective doses, the plasma and organ concentrations of suramin were far below those needed to exert signifi cant in vitro cytotoxic or cytostatic effects on B16F10 and M5076 cell s. Thus, in addition to the antineoplastic effect of suramin our resul ts indicate a potential antimetastatic role for this compound.