Effect of genistein on p90RSK phosphorylation and cell proliferation in T47D breast cancer cells.

BACKGROUND The molecular mechanisms of genistein's proliferative effects on breast cancer cells are largely unknown. This study aimed to examine estrogen-receptor (ER)-related signaling molecules involved in genistein-associated cell proliferation and survival (ERK1/2, p90RSK, JNK, Akt and NFκB) and to correlate these results to cell proliferation. MATERIALS AND METHODS The effect of genistein on cell-signaling molecules was determined in T47D breast cancer cells by a Bioplex phosphoprotein detection kit. These results were confirmed by Western blotting and were correlated to cell proliferation by MTT assay. RESULTS Low and high concentrations of genistein induced an ERK1/2-independent decrease in phosphorylated p90RSK. This effect was accompanied by decreased cell proliferation at high concentrations and an increased response at low concentrations of genistein following a 48-hour exposure. CONCLUSION Concentration-dependent actions of genistein in T47D cells may be due to differential activation of signaling molecules.