Figure 5.

Inhibition of radiation induced NF-κB activation and increased apoptosis by pre-treatment with genistein in PC-3 cells. (A) PC-3 cells were treated with 30 μmol/L genistein for 24 hr then irradiated with 3 Gy photons. At 30 min post-radiation, cells were processed for isolation of nuclear protein. NF-κB DNA binding activity in 10 μg of nuclear extract was determined using EMSA. The level of DNA binding activity is expressed as the mean integrated density value (I.D.V.) from 3 separate experiments (± S.E.M.). (B) The level of the 85-kDa cleaved PARP protein in 20 μg of nuclear extract was determined by western blot analysis. Data are presented as the mean integrated density value (I.D.V.) of 3 separate experiments (± S.E.M.). (Con): control, untreated-cells; (Rad): cells irradiated with 3 Gy photons; (Gen): cells treated with 30 μmol/L genistein; (Gen + Rad): cells pre-treated with 30 μmol/L genistein for 24 hr then irradiated with 3 Gy photons. Retinoblastoma protein (Rb) was used as a nuclear protein loading control; (*): value statistically significant from control at p < 0.05.