EGCG Promoting Apoptosis Of Human Prostate Cancer Cell PC-3 And Its Influence On The Expressions Of Survivin Protein

Objective To investigate the influence of proliferation and apoptosis and the expressions of survivin protein in human prostate cancer cell PC-3 induced by different concentrations of epigallocat-echin-3-gallate (EGCG) . Our research aimly provided a theoretical basis for the EGCG treatment in Androgen Independent Prostate Cancer(AIPC).Methods 1. Human prostate cancer cell PC-3 were cultured in vitro and treated with various concentrations of EGCG, respectively. The morphological changes of cells were observed by inverted microscope. 2. After treated with various concentration of EGCG(0, 20, 40, 80μg/ml), the cell proliferation was measured by growth curve and clonogenic assay. 3. Flow Cytometry was used to analyze the changes of cell cycle and apatosis treated with various concentrations of EGCG(48 hours later). 4. The expression of Survivin mRNA were detected by reverse transcription-polymerase chain reaction(RT-PCR) assay(48 hours later). 5. The expression of Survivin protein were detected by western blot assay (48 hours later). Results 1. The PC-3 cells became roll and small after treated with EGCG, but control group cells were still polygon and cytoplasm full. When increasing the concentrations of the EGCG, some floating and dead cells could be seen in the inverted microscopy. 2. By using cell proliferation curve and colony forming assay, EGCG significantly inhibited PC-3 cell proliferation when PC-3 dealing with different concentrations of EGCG (0,20,40,80μg/ml), compared with the control group. When increasing of the concentration of EGCG and elongation of the treated time, the proliferation ability of PC-3 cells was inhibited in a dose-and time-dependent manner.(P<0.05) 3. When PC-3 cells dealing with different concentrations of EGCG (0,20,40, 80μg/ml), the apoptosis rate of PC-3 cells were: (1.96±0.90)%,(3.11±1.37)%,(12.32±1.82)%,(26.51±2.19)%, respectively. Compared with the control group, the apoptosis rate of PC-3 cells treated by EGCG raised up significantly (P<0.05). 4. After treated with various concentration of EGCG for 48h, G1 phase cells increased compare to control group. The ratio of G1 phase cells of control group and EGCG treatment groups(0,20,40,80μg/ml) were (30.66±1.30)%,(35.28±2.02)%,(43.78±2.23)%,(56.81±2.01)%, respectively. Compared to control group, the experimental groups could be significantly arrested in G1 phase(p<0.05). 5. EGCG could down-regulate the expression of survivin mRNA, in a dose-dependent manner after treated with various concentration of EGCG for 48 hours later(P<0.01). 6. EGCG could down-regulate the expression of survivin protein in a dose-dependent manner after treated with various concentration of EGCG for 48 hours later(P<0.01).Conclusions EGCG can inhibit the proliferation of PC-3 cell and promote them apoptosis, The PC-3 cells proliferation ability was inhibited in a dose-and time-dependent manner, the possible mechanism might be related to downregulate the expression of survivin.