Vanadium Pentoxide Induces the Secretion of CXCL9 and CXCL10 Chemokines in Thyroid Cells

Vanadium is a grey metal, existing in different states of oxidation, whose most common form in commercial products is vanadium pentoxide (V2O5). All vanadium compounds have been considered toxic. A carcinogenic role of vanadium on the thyroid has recently been proposed. However no in vivo or in vitro studies have evaluated thyroid disruption in humans and/or animals after exposure to vanadium. In the present study we evaluate the effect of V2O5 on proliferation, and chemokine secretion in normal thyrocytes. Our study demonstrated that V2O5 has no effect on thyroid follicular cell viability or proliferation, but it is able to induce the secretion of T-helper (Th)1 chemokines into the thyroid, synergistically increasing the effect of important Th1 cytokines such as interferon (IFN)γ and tumor necrosis factor (TNF)α. Through this process, V2O5 promotes the induction and perpetuation of an inflammatory reaction in the thyroid. Further studies are necessary to evaluate thyroid function, and nodules, in subjects occupationally exposed, or living in polluted areas.