Proteomic study on the inhibitory effects of genistein on human breast cancer cells

Objective: To investigate the inhibitory effects of low concentration of genistein on human breast cancer cell line MCF-7 and explore its molecular mechanism using proteomic technologies. Methods: Log phase cells were cultured in 96-well plates at a density of 1 × 10 ³ cells/well with 25μmol/L genistein for 1 to 7 days respectively to obtain growth curve by MTT assay. Sequential protein extraction was used and proteins were fractionated as soluble or hydrophobic fractions which were then analyzed by 2-DE. Spots were detected and evaluated by 2D platinum Software 5.0 and the spots with different expression level were subjected to MS analysis. Results: Genistein of 25 μmol/L obviously inhibited the growth of MCF-7 cells and could induce apoptosis of the cells after 4 days' cultivation; 2-DE patterns demonstrated a good resolution either for soluble proteins or for hydrophobic proteins. Moreover, 24 significant proteins were identified, among which 19 were up-regulated and 5 were down-regulated. Conclusion: These proteins' functions are involved in many aspects of cell physiological functions such as growth regulation, stress response, cell morphogenesis and apoptosis.