Induction effect of nano-SiO_2 on apoptosis of neuroblastoma SH-SY5Y cells and its mechanism

Objective To observe the effects of nano-SiO2 on apoptosis and cell cycle of human neuroblastoma SHSY5 Y cells,and to explore the mechanism. Methods The SH-SY5 Y cells were treated with different concentrations of 90 nm SiO2 and divided into 0,3.125,6.250,12.500,25.000,and 50.000 mg·L-1 SiO2 groups.The survival rates of the cells in various groups were assessed by MTT method;the apoptotic rates of SHSY5 Ycells were determined by AO/EB staining and Annexin Ⅴ-FITC/P method;the percentage of cell cycle and the level of intracellular reactive oxygen species(ROS) were tested by flow cytometry(FCM) method.Results The MTT results showed the survival rates of the cells in 6.250,12.500,25.000 and 50.000mg·L-1SiO2 groups were significantly lower than that in control group(P0.05);the survival rates of the cells in 12.500,25.000,and 50.000mg·L-1 SiO2 groups were significantly lower than that in 3.125mg·L-1 SiO2group(P0.05);the AO/EB staining and Annexin Ⅴ-FITC/PI results showed the apoptotic rates of the cells in 6.250,12.500,25.000,and 50.000 mg·L-1 SiO2 groups were higher than that in control group(P0.05);the apoptotic rates of the cells in 12.500,25.000,and 50.000 mg· L-1 SiO2 groups were higher than that in3.125mg·L-1 group(P0.05).The FCM results showed the levels of ROS of the cells in 3.125,6.250,12.500,25.000,and 50.000mg·L-1 SiO2 groups were significantly higher than that in control group(P0.05);compared with control group,the percentages of the cells at G0/G1 phase in 25.000 and 50.000 mg·L-1 SiO2 groups were increased(P0.05);the percentage of the cells at G2/M phase in 50.000mg·L-1 SiO2 group was increasd(P0.05).Conclusion Nano-SiO2 can decrease the activity of SH-SY5 Ycells and increase the apoptosis and the level of ROS,and nano-SiO2 can interfere the cell cycle and inhibit the proliferation of SH-SY5 Ycells.