Genistein inhibit the proliferation induced by zearalenone in MCF-7 cells

Zearalenone (ZEA) is a nonsteroidal estrogenic mycotoxin and exists widely in the moldy feeds and food. Genistein (GEN) is a natural isoflavone phytoestrogen. ZEA has adverse effects on animal's reproduction performance and immunologic function, also can induce the proliferation of MCF-7 cells. However, the interactive effect of ZEA and GEN on proliferation and cell cycle in MCF-7 cells is remain poorly understood. Here, the interactive effect of ZEA and GEN on proliferation and cell cycle in MCF-7 cells were determined through MTT assay and flow cytometry, respectively. Results demonstrated that ZEA (10 and 20 nM) could stimulate the proliferation of MCF-7 cells and significantly increase S phase distribution (P<0.05). RT-PCR analysis revealed that ZEA could significantly increase estrogen receptor (ER) a mRNA expression (P < 0.05), while GEN (16 and 32 mu M) could inhibit proliferation and lessen S phase distribution of MCF-7 cells (P<0.05) which were induced by ZEA. In the co-administration treatments of GEN and ZEA, ER alpha mRNA expression decreased, bcl-2 decreased and bax increased at both mRNA and protein levels compared to those with ZEA alone. These results showed that the proliferative activity of ZEA could be repressed by GEN through regulating the expression of ER, bax and bcl-2 in MCF-7 cells.