Exogenous Nitric Oxide Induced Gastric Cancer SGC-7901 Cell Apoptosis

Objective To investigate the potential affect of exogenous nitric oxide(NO) induced apoptosis of moderately differentiated gastric cancer cell(SGC-7901).Method Cells were treated by different concentrations of sodium nitroprusside(SNP), which act as exogenous NO. The survival ate of cells were detected by MTT assay. The study was divided into four groups: blank control group, reactive oxygen species(ROS) inhibitors(N-acetyl-L-cysteine, NAC) group, SNP group and NAC-SNP group. The apoptosis morphology and apoptosis rate of cells were obtained by fluorescence microscopy. Levels of ROS were observed by fluorescent chemiluminescence detector in cells; Standard curve method was developed for the determination of NO in each cell production; Protein levels of Cu/Zn-superoxide dismutase(Cu/Zn-SOD) were extracted for Western-blot analysis. All data was analyzed by SPSS17.0.Resμlt(1) Exogenous nitric oxide has the inhibitory effect on the gastric cancer SGC–7901 cells, and its inhibition has a concentration dependence and time dependence on exogenous NO(P < 0.05).(2) Exogenous nitric oxide can induce gastric cancer SGC- 7901 cells apoptosis(P < 0.05).(3) There were no significant differences in cell apoptosis rate and the active oxygen level between NAC group and blank control group(P > 0.05). Compared to blank control group, apoptosis rate of cells was significant upregμlated in SNP group and NAC-SNP group(P < 0.05), besides, in the two groups, level of ROS was obviously up-regμlated. What’s more, apoptosis rate of cells and level of ROS were significantly increased in SNP group compared to NAC-SNP group, and in two aspects there were significant statistical difference between the groups(P<0.05).(4) SNP coμld cause the decrease of Cu/Zn-SOD protein expression in gastric cells.Conclusion Exogenous NO reduce intracellμlar Cu/Zn-superoxide dismutase(Cu/ZnSOD) protein expression by raising the levels of ROS in gastric cancer cells. And elevated ROS are involved in the gastric cancer cell apoptosis induced by exogenous NO way.