In vitro study on the antitumor activity of several new polyoxometalates

Polyoxometalates (POMs) are negatively charged clusters consisting of transition metals and oxygen atoms. There are two general types of POM activity, antiviral and antitumoral, have dominated the medicinal chemistry of these compounds. Based on synthesized four different kind of POMs, [Ce(H₂O)₇Cr(OH)₆Mo₆O₁₈]_n·4nH₂O, [Sm(H₂O)₇Cr(OH)₆Mo₆O₁₈]_n·4nH₂O, Eu(H₂O)₇Cr(OH)_6- Mo₆O₁₈]_n·4nH₂O, and K₆[P₂W₁₈O₆₂]·14H₂O, we investigate their antitumor effect in vitro. K₆[P₂W₁₈O₆₂]·14H₂O exerted the most strong activity. IC₅₀ of it for MCF-7, SKOV-3 and HepG2 were 22μmol/L, 19μmol/L and 24nmol/L respectively. Lower concentration of K₆[P₂W₁₈O₆₂]·14H₂O could induce HepG2 cells apoptosis. It up-regulated the expression of Bax and Bim, apoptosis promoting members in Bcl-2 family, so the mechanism of this effect may through mitochondria path way.