The Role of Magnesium as Immunomodulator and Mediator between Immune and Colon Cancer Cells

Background: Magnesium is one of the most abundant ions in the cells and plays a significant role in maintaining the adequate function of various systems including the immune one. Studies have revealed association between magnesium and tumorigenesis. We sought to examine the effect of magnesium on the capacity of human peripheral blood mononuclear cells (PBMC) for cytokine production and its impact on the interplay between immune- and human colon cancer cells from two lines.

Methods: PBMC were incubated with various concentrations of MgSO4 as a source for magnesium and the secretion of TNFα, IL-1β, IL-1ra, IL-6, IL-2, IL-10, and IFNγ was evaluated. In another set of experiments various concentrations of magnesium were added to co-cultures of PBMC and HT-29 or with RKO colon carcinoma cells and cytokine secretion was examined.

Results: Magnesium sulfate added to non-stimulated or mitogen-stimulated human PBMC at various concentrations exerted no effect on the secretion of the cytokines examined, except for reduced IL-6 and stimulated IL-1ra production at high magnesium concentrations. Inhibited secretion of TNFα, IL-1β, IL-6 and IFNγ and enhanced production of IL-1ra by HT-29 stimulated PBMC was observed upon incubation with magnesium sulfate, whereas that induced by RKO cells was not affected except for increased IL-2 production..

Conclusion: In addition to its multiple physiological activities magnesium is an immunomodulator able to control inflammatory processes by participating in immune cells’ activity. The results insinuate a supplementary role of magnesium in the immune dialogue between immune and cancer cells from certain human colon carcinoma lines.

Keywords: Magnesium sulfate; cytokines; mononuclear cells; colon cancer; immunity; cross-talk.