Iron as a potential co-factor in the pathogenesis of Kaposi's sarcoma?

The role of iron in the pathogenesis of several tumours is being increasingly investigated. In particular, its involvement in the pathogenesis of Kaposi's sarcoma (KS) is suggested by the distribution of the endemic form of KS corresponding to continental rifts and associated iron-oxide-rich volcanic clays. We investigated in vitro to what extent iron supplementation or withdrawal could affect the growth of KS-derived cells, by analysing the effects of adding iron salts (iron chloride and ferric nitrilotriacetate) and/or reducing iron by iron chelators (desferrioxamine) on KS-derived cell cultures. The addition of iron salts strongly stimulated the growth of KS cells, as reflected by increase in thymidine incorporation and cell number. Conversely, desferrioxamine and deferiprone inhibited cell growth. The inhibitory effect of iron chelation was more pronounced on rapidly dividing basic fibroblast-growth-factor-stimulated cells. These results may point to a novel therapeutic approach to KS.