Effect of silencing Bcl-2 expression by small interfering RNA on radiosensitivity of gastric cancer BGC823 cells

Objective: To explore the influence of silencing Bcl-2 expression by small interfering RNA (siRNA) on Bcl-2 protein expression, cell apoptosis rate and radiosensitivity of gastric cancer BGC823 cells. Methods: siRNA segment for Bcl-2 gene was designed and synthesized, then was induced into gastric cancer BGC 823 cells by liposome transfection. Bcl-2 protein expression was detected by Western Blotting. After X radiation, flow cytometry and clone forming assay were used to determine the effects of RNA interference on BGC823 cell apoptosis rate and radiosensitivity. Result: After the transfection of Bcl-2 siRNA, the positive expression rate of Bcl-2 protein in BGC823 cells was (35.46 +/- 2.35)%. Compared with the control group and negative siRNA transfection group, the rate was significantly decreased (P<0.01). The apoptosis rate of BGC823-RNAi cell was (10.81 +/- 0.91)%, which was significantly higher than the control group and negative siRNA transfection group (p<0.01). After 48h X radiation, the apoptosis rate of BGC823-RNAi was (28.91 +/- 1.40)%, which was significantly higher than the control group and the group without radiation (P<0.01). During clone forming assay D-o, D-q and SF2, values in Bcl-2 siRNA1 transfection group were all lower than those in the control group. The radiosensitivity ratio was 1.28 (the ratio of Do) and 1.60 (the ratio of D-q). Conclusions: Specific siRNA of Bcl-2 gene can effectively inhibit the expression of Bcl-2 gene, enhance the radiosensitivity and apoptosis of gastric cancer BGC823 cells, having good clinical application perspective.