DIM enhances effect of cis-diamminedichloroplatinum on growth inhibition and apoptosis in human prostate cancer cell PC-3

AIM: To study the effects of the combination of cis-diamminedichloroplatinum(DDP) and 3,3-diindolylmethane(DIM) on the growth and apoptosis of human prostate cancer cell PC-3.METHODS: MTT method was applied to detect the cell growth inhibitory rate.The cell apoptosis was measured by the flow cytometry and acridine orange staining method.The expression of the anti-oncogene p21 was detected by RT-PCR technique.RESULTS: The combination of 60 μmol·L-1 DIM and 0.4 mg·L-1 DDP effectively inhibited the growth and induced apoptosis in PC-3 cells.This result was the same as the effect of using 4 mg·L-1 DDP only.The cell growth inhibitory and apoptosis rates for the combination of DIM and DDP were much higher than those for the individual effect.Both the combination and the single effect of these two medicines(i.e.,DIM and DDP) all strengthen p21 mRNA expression significantly,and the effect of combination was more significant.CONCLUSION: DIM significantly enhances the effects of DDP on the growth inhibition and apoptosis induction in PC-3 cells.