INOSITOL PHOSPHATES HAVE NOVEL ANTICANCER FUNCTION

Inositol hexaphosphate (InsP(6), phytic acid) is ubiquitous in the pla nt kingdom and is abundant in cereals and legumes. In much smaller amo unts InsP(6) and its lower phosphorylated forms (InsP(1-5)) are contai ned in most mammalian cells, where they are important in regulating vi tal cellular functions. Both in vivo and in vitro experiments have sug gested striking anticancer potential (preventive as well as therapeuti c) for InsP(6) with and without inositol. In addition to reduce cell p roliferation, InsP(6) increases differentiation of malignant cells oft en resulting in reversion to the normal phenotype. InsP(6) is quickly absorbed from the rat stomach and upper intestine and distributed as i nositol and InsP(1). In vitro it is instantaneously taken up by malign ant cells undergoing variable dephosphorylation to inositol and InsP(1 -5), pointing toward their role in mediating the action of InsP(6). Be cause InsP(6) is high in high-fiber diets, our studies also may explai n, at least in part, the epidemiologic observation showing high-fiber diets are associated with a lower incidence of certain cancers. Althou gh further studies are needed to elucidate the mechanism(s) of this ac tion, inclusion of InsP(6) in our strategies for cancer prevention and therapy is warranted.