The Task of Desferrioxamine and Iron in the Immune Interplay between mononuclears and Colon Cancer Cells

Background: Macrophages and especially the tumor related ones play an essential role on malignant cell proliferation since they are tightly connected with iron absorption and release. The present study was designed to examine the role of iron and desferrioxamine on the immune interaction between human peripheral blood mononuclear cells (PBMC) and human colon carcinoma lines HT-29 and RKO. Materials and Methods: PBMC co-cultured with either HT-29 or RKO cells were depleted of iron by desferrioxamine (DFO). TNFα, IL-1β, IL-6, IFNγ, IL-2, IL-10 and IL-1ra concentration in the supernatants were examined by ELISA on various combinations of iron depleted and non-depleted PBMC and malignant cells. Results: DFO added to PBMC incubated with HT-29 cells, caused inhibited secretion of TNFα, IFNβ, IL-1ra and IL-10 whereas IL-1β, IL-6 and IL-2 production was not affected. Addition of DFO to PBMC cultured with RKO cells resulted in reduction of IL-1ra and IL-10 generation only. Depletion of iron from either PBMC or malignant cells and the addition of iron affected differently cytokine production. Conclusions: Both iron and DFO affect inflammatory cytokine production by human PBMC and intervene in the cross-talk between immune and colon cancer cells from two lines examined. The study enlightens the way iron and DFO may modulate tumorigenesis.