Suramin: prototype of a new generation of antitumor compounds.

Suramin is a polysulfonated compound originally developed nearly 75 years ago for use as a trypanocidal agent. Recent studies indicate that suramin can also disrupt mammalian cell function, notably by blocking growth factor--receptor interactions and by inhibiting the activity of enzymes that are critical for cell growth and proliferation. These observations, together with the finding that clinically achievable concentrations of the drug are toxic to many human tumor cell lines, have prompted clinical investigations of suramin's efficacy as an antitumor agent. This review considers the possible mechanisms that may underlie suramin's cytotoxic effects and discusses ongoing clinical trials in cancer patients.