Genistein inhibits the contact-stimulated migration of prostate cancer cells.

The results of several epidemiological studies have suggested that a soybean-based diet is associated with a lower risk of prostate cancer. We investigated the effect of the soy isoflavone genistein on the proliferation and contact-stimulated migration of rat prostatic carcinoma MAT-LyLu and AT-2 cell lines. Genistein almost completely inhibited the growth of both MAT-LyLu and AT-2 cells in the concentration range from 25 to 100 muM, but the addition of 1 muM genistein to the medium significantly stimulated the proliferation of both cell lines. Additionally, at concentrations above 25 muM, genistein showed a potent cytotoxic effect. However, the central finding of this study is that at physiologically relevant concentrations (1 muM and 10 muM), genistein inhibits the motility of prostate cancer cells stimulated by homo-and heterotypic contacts. These results show that at physiological concentrations, genistein exerts an inhibitory effect on the migration of prostate cancer cells and suggest that it may be one of the factors responsible for the anti-metastatic activity of plant isoflavonoids.