[Suramin activity in human head and neck squamous cell carcinoma cell lines]

Suramin, a drug used for the treatment of African trypanosomiasis and onchoceriasis, has potential anti-cancer activity. As to the mechanism of action, it is considered to interfere with the action of tumor growth factor and specific growth enzymes. In the present study, the effect of suramin on proliferation of human head and neck squamous cell carcinoma cells was determined. A significant growth inhibition in all three cell lines tested was observed when the concentration of suramin was 100 micrograms/ml or more. The hypothesis was tested to ascertain whether growth inhibition may be due to selective interference with the action of epidermal growth factor. Suramin at growth inhibiting concentrations only partly antagonized the growth stimulating effect of EGF indicating that other mechanisms of action may also contribute to the growth inhibitory activity of suramin. Furthermore, evidence was found that serum proteins other than growth factors presented in the culture medium have a growth stimulating effect on cells and a strongly antagonistical effect on suramin activity.