Influence of stable transfection of bcl-2shRNA combined with γ irradiation on apoptosis of the gastric carcinoma cell line SGC-7901

Objective To observe the effect of bcl-2 gene-specific RNA interference combined with γ irradiation on apoptosis and radiosensitivity of the gastric carcinoma cell line SGC7901.Methods The recombinant eukaryotic expression vector pGPH1/GFP/Neo designed to target the bcl-2 gene was transfected into SGC7901 cells by lipofectamin.Stable positive clones were selected with G418.After γ irradiation,the cells were divided into 4 groups: SGC-7901(group A),irradiation/SGC-7901(group B),Bcl-2shRNA/SGC-7901(group C) and irradiation/Bcl-2shRNA/SGC-7901(group D).Cell proliferation was detected by CCK-8.Cell apoptosis was observed by AO/PE.The apoptosis rate was determined by flow cytometry.Expression of bcl-2 was determined by Western blot,and compared between transfection cells and non-transfection cells.Results Western blot analysis indicated that expression of bcl-2 was suppressed by shRNA and irradiation,and they had a synergetic effect.The growth of cells in group D was obviously slower than that in the other groups(P 0.05).Cell inhibitory rates in groups B,C and D were(27.00±5.27)%,(30.10±6.49)% and(98.40±11.35)%,respectively.Apoptosis rates in groups A,B,C and D were(3.80±0.22)%,(20.80±4.15)%,(23.20±4.15)% and(92.90±25.90)%,respectively(P 0.05).Conclusions Bcl-2 gene suppression by RNAi and irradiation can induce cell apoptosis,co-inhibit expression of bcl-2,and obviously increase radiosensitivity in the human gastric cell line.