Does altered oxygenation or reactive oxygen species alter cell turnover of BeWo choriocarcinoma cells?

This study assessed the effect of 20 and 6% ambient oxygen (O2) or 5–50 μmol/l hydrogen peroxide (H2O2) on apoptosis, necrosis, proliferation and fusion of BeWo cells. The expression of p53, Mdm2 and Bax was assessed by western blotting. Apoptosis was increased in cells cultured in 6% O2 tension and 50 μmol/l H2O2 (P < 0.05, P < 0.01 by ADP:ATP ratio). In the same conditions, cell viability as estimated by the MTT assay was decreased (6% O2P < 0.01, 50 μmol/l H2O2P < 0.05). Human chorionic gonadotrophin secretion was decreased by culture in 6%O2 and 50 μmol/l H2O2 (P < 0.05). Cell fusion was also decreased by treatment with 50 μmol/l H2O2 (P < 0.05). Treatment with 50 μmol/l H2O2 was associated with increased expression of p53 and decreased expression of Mdm2 (P < 0.05). This study provides evidence that BeWo cell turnover is altered following exposure to hypoxia or ROS. It is concluded that BeWo cell culture is an appropriate model for investigating the regulation of trophoblast cell turnover. In addition, these data support a role for p53 in mediating altered trophoblast cell turnover in response to oxidative stress.