Objective To investigate the inhibitory effect of ginsenoside Rg3 combined with cisplatin (DDP) on DDP-resistant cell line SGC-7901/DDP and their molecular mechanism.Methods SGC-7901/DDP cells were divided into four groups including a control group,a ginsenoside Rg3 (40 μg/ml) treatment group,a DDP (1.40 μg/ml) treatment group,and a drug combination treatment group.The proliferation ability of SGC-7901/DDP cells was detected by MTT,EdU,and colony formation assays.The apoptosis ability of SGC-7901/DDP cell was detected by flow cytometry and Hoechst 33342 staining.The protein levels of apoptosis-related markers were detected by Western blotting.The migration ability of SGC-7901/DDP cells was detected by wound healing and Transwell assays.The expression levels of proteins in epithelial-mesenchymal transformation (EMT) and Wnt/β-catenin signaling pathway were determined by Western blotting and immunofluorescence staining.Results Compared with the ginsenoside Rg3 or the DDP treatment groups,the drug combination treatment group inhibited the proliferation (t=8.062,P=0.001;t=7.090,P=0.002),colony formation (t=8.062,P=0.001;t=6.144,P=0.004),and migration (t=7.424,P=0.002;t=4.317,P=0.013),and promoted the apoptosis (t=5.530,P=0.031;t=6.036,P=0.026) of SGC-7901/DDP cells.Compared with the ginsenoside Rg3 and the DDP treatment groups,the drug combination treatment group down-regulated the expression levels of EMT-associated proteins including vimentin (t=24.450,P<0.001;t=14.750,P<0.001),Snail (t=29.640,P<0.001;t=70.700,P<0.001),Slug (t=89.230,P<0.001;t=87.360,P<0.001),matrix metalloproteinase (MMP) 2 (t=84.540,P<0.001;t=67.120,P<0.001),and MMP9 (t=19.010,P<0.001;t=10.890,P<0.001),as well as those of Wnt/β-catenin signaling pathway related proteins including Wnt (t=35.480,P<0.001;t=14.670,P<0.001),β-catenin (t=155.800,P<0.001;t=118.100,P<0.001),C-myc (t=20.870,P<0.001;t=3.334,P=0.029),and cyclin D1 (t=5.007,P=0.008;t=8.347,P=0.001).Meanwhile,it up-regulated the expression of epithelial cells including E-cadherin (t=36.450,P<0.001;t=33.810,P<0.001) and ZO-1 (t=37.060,P<0.001;t=37.030,P<0.001).Conclusion Ginsenoside Rg3 enhanced the sensitivity of SGC-7901/DDP cells to DDP by inhibiting the activity of Wnt/β-catenin signaling pathway.
Keywords: Wnt/β-catenin; cisplatin; epithelial-mesenchymal transformation; ginsenoside Rg3; proliferation.