RESUMO
BACKGROUND/AIM: Genistein (4', 5, 7-trihydroxyisoflavone) and daidzein (4', 7-dihydroxyisoflavone) are isoflavones derived from soybean and have anti-cancer effects in various cells. However, the effects of genistein and daidzein on the human osteosarcoma cell line Saos-2 has not been investigated before. MATERIALS AND METHODS: Human osteosarcoma Saos-2 cells were treated with genistein for 24 and 48 hours. Cytotoxicity and apoptosis were measured. RESULTS: Genistein significantly inhibited proliferation of Saos-2 cells stronger than daidzein in a dose-dependent manner (0 to 80 µM). Genistein also significantly suppressed Saos-2 cell viability in a dose-dependent manner (0 to 100 µM). In contrast, daidzein did not affect Saos-2 cell viability. Real-time PCR revealed that genistein caused G1-arrest by increasing the expression of p21 and p27 mRNAs in Saos-2 cells. In addition, genistein induced apoptosis through the up-regulation of effector caspase-3/7 activity in Saos-2 cells. Genistein also enhanced initiator caspase-9 and TNF-α mRNA expression in cells. CONCLUSION: Genistein may inhibit proliferation through the up-regulation of p21 and p27 and viability by inducing apoptosis in Saos-2 cells.
