Abstract:

Objective To observe the effects of nano-SiO₂ on apoptosis and cell cycle of human neuroblastoma SH-SY5Y cells,and to explore the mechanism.Methods The SH-SY5Y 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 SH-SY5Y cells 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 50.000 mg·L^-1 SiO₂ groups were significantly lower than that in control group (P<0.05);the survival rates of the cells in 12.500,25.000, and 50.000 mg·L^-1 SiO₂ groups were significantly lower than that in 3.125 mg·L^-1 SiO₂ group (P<0.05); 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(P<0.05);the apoptotic rates of the cells in 12.500,25.000,and 50.000 mg·L^-1 SiO₂ groups were higher than that in 3.125 mg·L^-1 group(P<0.05).The FCM results showed the levels of ROS of the cells in 3.125,6.250,12.500,25.000, and 50.000 mg·L^-1 SiO₂ groups were significantly higher than that in control group (P<0.05); 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 (P<0.05);the percentage of the cells at G₂/M phase in 50.000 mg·L^-1 SiO₂ group was increasd (P<0.05).Conclusion Nano-SiO₂ can decrease the activity of SH-SY5Y cells and increase the apoptosis and the level of ROS,and nano-SiO₂ can interfere the cell cycle and inhibit the proliferation of SH-SY5Y cells.

Key words: nano-SiO₂, SH-SY5Y cells, cell cycle, apoptosis