VANADIUM AS A MODULATOR OF CELLULAR REGULATORY CASCADES AND ONCOGENE EXPRESSION

Vanadium, a trace metal in the environment and in biological systems, influences the behavior of enzymes, mimics and regulates growth factor activity, is a potential mutagenic and carcinogenic agent, and regula tes gene expression. The diverse biological actions of vanadium result from its capacity to function as an oxyanion, oxycation, or prooxidan t. Vanadium is found in water, rocks, and soils in low concentration a nd in relatively high concentrations in coal and oil deposits. Vanadiu m compounds at much higher concentrations than are typically ingested are being considered in the treatment of diabetes mellitus. The action s of insulin and vanadium on the insulin receptor are similar, but the mechanisms are not identical. Vanadium modulates growth-factor-mediat ed signal transduction pathways. Vanadium promotes cell transformation and diminishes cell adhesion. Consistent with its mitogenic action an d its capacity to mimic mitogenic growth factors, vanadium stimulates expression of protooncogenes. In particular, oxygen-derived active spe cies are involved in the expression of the jun protooncogene in the pr esence of vanadium. The unique cellular activity of vanadium makes it a tool of unparalleled potential for studying mechanisms of cell growt h, differentiation, and metabolism.