Epigallocatechin Gallate Enhances Inhibition Effect of DDP on the Proliferation of Gastric Cancer BGC-823 Cells by Regulating p19Arf-p53-p21Cip1 Signaling Pathway

Objective: To indicate the effect of Epigallocatechin gallate (EGCG) and Cisplatin (DDP) on proliferation of gastric cancer BGC-823 cells and the relative underlying mechanism. Methods: Cultured BGC-823 cells were treated by 5 μg/mL DDP, 25 μg/mL EGCG and combined 5 μg/mL DDP with 25 μg/mL EGCG, a blank group was used as control. Cell morphology was observed by 4’,6-diamidino-2-phenylindole (DAPI) staining. The ability of cell proliferation was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)assay. The cell cloning rate was determined by colony formation assay. The ability of cell migration was detected by cell scratch test. The cell cycle distributions and apoptosis were analyzed by flow cytometry, The expression of p19Arf, p53, p21Cip1 mRNA was determined by RT-qPCR. The protein levels of p19Arf, p53, p21Cip1 were measured by Western blot. Results: Compared with DDP or EGCG treatment alone, EGCG combined with DDP treatment significantly caused nuclear shrinkage, reduced the proliferation rate, the ability of cell clone and migration. EGCG combined with DDP treatment caused cell cycle arrest in G1 phase in BGC-823 cells, increase of apoptosis (21.3%) vs EGCG (7.25%) and DDP (3.86%) single-use group (p <0.01), up-regulated gene and protein expressions of p19Arf, p53, p21Cip1 (p <0.01). Conclusion: EGCG can enhance the effect of DDP on inhibiting BGC-823 cell proliferation and inducing apoptosis via activating the p19Arf-p53-p21Cip1 signaling pathway.