Effect of arsenic trioxide in inducing apoptosis and expression of Fas/FasL of gastric tumor cells in nude mice

Objective To study the effect of arsenic trioxide(As2O3) on the expression of Fas/FasL and in inducing apoptosis of gastric tumor cells in nude mice.Methods The xenograft model was established in 30 male BALB/C-nu/nu mice.The mice were randomly divided into 3 groups and injected intraperitoneally with As2O3(2.5mg/kg or 5mg/kg) or with saline solution of the same volume respectively.Tumor growth was detected by measuring tumor volume.Apoptosis of the tumor cells was measured with transmission electron microscope(TEM) and TdT-mediated dUTP nick end labeling(TUNEL).The expression of Fas/FasL in the tumor cells was detected with immunohistochemistry.Results Tumor volume in As2O3-treated groups was smaller than that in control group(P0.05).Apoptotic cells in the As2O3-treated groups significantly outnumbered than those in control group(P0.01).The expression of Fas in tumor cells was higher in the As2O3-treated groups than in control group(P0.05),but FasL expression of tumor cells did not differ between the treated groups and control group(P0.05).Conclusion As2O3 can obviously inhibit the growth of human gastric tumor.One of the mechanisms is up-regulation of Fas gene that can induce the apoptosis of gastric cells.