Effects of daidzein on estrogen-receptor-positive and negative pancreatic cancer cells in vitro.

AIM: To study the effects of daidzein on human pancreatic cancer cells in vitro. METHODS: Human estrogen-receptor (ER)-positive pancreatic cancer cells MiaPaCa-2 and ER-negative pancreatic cancer cells PANC-1 were treated by 0.1 micromol/L, 1 micromol/L, 10 microL, 25 microL, 50 microL, 75 microL and 100 microL of daidzein, respectively. Its antiproliferative effect was studied by MTT assay. RESULTS: Daidzein inhibited the growth of MiaPaCa-2 and PANC-1 cells at the concentrations from 0.1 microL to 100 microL. A dose- and time-dependent manner was found. The IC(50) of daidzein on MiaPaCa-2 and PANC-1 cells was 45 microL and 75 micro, respectively. After MiaPaCa-2 cells were treated by daidzein for 3 d and at the concentrations more than IC(50), the inhibitory manner was identical and the inhibition appeared a saturation phenomenon, but the inhibitory manner of daidzein on PANC-1 cells was different from that of MiaPaCa-2 cells. CONCLUSION: Daidzein has antiproliferative effects on human estrogen-receptor-positive and negative pancreatic cancer cells, but their mechanisms may be different.