
<ArticleTitle>Overexpression of <prot>HER-2</prot>/<prot>neu</prot> enhances the sensitivity of human bladder cancer cells to urinary isoflavones.</ArticleTitle>
<AbstractText>Soybean foods have been suggested to be practical chemopreventives for human urinary tract cancers. Recently, we demonstrated that the co-operative action of isoflavones results in an increased dose-dependent growth inhibition and apoptosis than any single isoflavone compound. This study aimed to examine the potential of <prot>HER-2</prot>/<prot>neu</prot> as a biological target for soy isoflavones. The sensitivity of the bladder cancer cell lines (n=7) to the isoflavones was inversely related to the amount of <prot>HER-2</prot>/<prot>neu</prot> expressed. By using <prot>HER-2</prot>/<prot>neu</prot> transfection experiments, all three stable transfectants showed a significant growth inhibition by the isoflavone mixture at concentrations attainable in normal adult urine. An increased inhibition of tyrosine phosphorylation of proteins immunoprecipitated by <prot>HER-2</prot>/<prot>Neu</prot> was observed in the neu-transfectants compared with controls. The results of this study suggest that <prot>HER-2</prot>/<prot>neu</prot> may be a practical biochemical target for urinary isoflavones in vivo.</AbstractText>
