Inhibition Of Proliferation And Induction Of Apoptosis In Human Gastric Cancer SGC-7901 Cell Line By Epigallocatechingallate (EGCG)

Aim To investigate the effect of epigallocatechin-3-gallate on on the proliferation inhibition and induction of apoptosis in gastric cancer cell line SGC-7901 and its molecular mechanisms.Methods Human gastric cancer (SGC-7901) cells were cultured in vitro. Cell counting method was used to test the influence of growth curve in SGC-7901 cells treated with different concentrations of EGCG. The growth inhibition of SGC-7901 cells was measured by clone formation assay. The apoptosis of SGC-7901 cells was determined by AO/EB fluorescence stain. Western blot analysis was performed to detect the expression of NF-kB(p65),Bcl-2,Bax and Caspase-3 protein.ResultsEGCG significantly inhibited the growth of SGC-7901 cells, in dose-dependent manner. Clone formation test have shown that EGCG inhibited significantly growth of SGC-7901 cells in a dose-dependent manner. The IC50 value of EGCG was 63.5μg/ml.Cell counting showed that average doubling time retarded from 34.50h in normal culture SGC-7901 cells to 35.99h in 40μg/ml EGCG experimented SGC-7901 cells, even to 94.74h in 40μg/ml EGCG experimented SGC-7901 cells.AO/EB fluorescence stain data provided evidence that the apoptosis of SGC-7901 cells induced by EGCG in a dose-dependent manner. The apoptosis of SGC-7901 cells after treatment with EGCG(Oμg/ml,40μg/ml,60μg/ml,80μg/mkl,100μg/ml,120μg/ml) for 48h were 5.4±0.12%,8.35±0.17%,31.11±0.42%.44.46±0.82%,66.5±0.62%,75.5±0.41%(P<0.05 VS control) respectively,;Western Blot analysis showed that NF-kB(p65) and Bcl-2 expression were decreased, while Bax and Caspase-3 expression were increased after exposure to EGCG (30μg/ml,60μg/ml,120μg/ml,48h). Conclusion1) EGCG on human gastric cancer cells (SGC-7901) with strong proliferation, the cell population doubling time was prolonged, extended cell cycle;2)Different concentrations of EGCG treatment of human gastric cancer cells (SGC-7901), inhibited cell growth and proliferation human gastric cancer (SGC-7901) cells;3) EGCG could significantly induce apoptosis of human gastric cancer cell SGC-7901 in a dose-dependent manner;4) EGCG with human gastric cancer SGC-7901 cells apoptosis, which may be associated with down-regulation of NF-kB(p65) expression and up-regulation of the ratio of Bax/Bcl-2, then activation of Caspase-3.