EFFECT OF SURAMIN ON HUMAN ESOPHAGEAL CANCER-CELLS IN-VITRO AND IN-VIVO

Background: Suramin disrupts several kinds of growth factor receptors. Since human esophageal squamous cell carcinoma expresses abundant epi dermal growth factor receptors (EGFR) and proliferates in an autocrine and paracrine manner, it was expected that suramin inhibits tumor gro wth by disrupting EGFR. Methods: We studied the effect of suramin on t he human esophageal squamous cell carcinoma cell line KEsC-II in vitro and in an animal model. Results: Cell proliferation was stimulated at a low concentration and inhibited at a high concentration of suramin in vitro. Since autophosphorylation of EGFR was stronger at the low co ncentration and weaker at the high concentration of suramin compared w ith the control, the effect of suramin was thought to be via phosphory lation of receptors. In the animal model tumor growth was significantl y stimulated in the suramin-treated group compared with the control gr oup, and the BrdU labeling index was also higher in the suramin-treate d group. Conclusions: As it was impossible to increase the dose of sur amin intravenously because of side effects, administration of suramin by another method, such as subcutaneous injection around the tumor, ma y increase the concentration of suramin in the tumor tissue and promot e the anti-tumor effect of suramin.