Abstract:

Objective To investigate the effects of glycidiazale sodium (CMNa) on radiosensitivity of children′s neuroblastoma SH-SY5Y cell line under normoxia and hypoxia conditions. Methods CMNa in different concentration was used on SH-SY5Y under normoxia and hypoxia. CCK-8 was employed to determine half maximal (50%) inhibitory concentration (IC) and 95% confidence interval.  Radiation absorbed doses of 0, 1, and 2 Gy were given to SH-SY5Y with 1 mmol/L CMNa (CMNa group) and normal SH-SY5Y (control group). Colony-forming assay was conducted to explore the cell proliferation. Flow cytometry was conducted to test cell cycle and their apoptosis. Western blotting was employed to test expression changes of cell cycle and apoptosis-related proteins. Results Under normoxia and hypoxia conditions, values of IC50 (95%CI) of SH-SY5Y were 3.62 (3.07-4.26) mmol/L and 1.59 (1.20-2.12) mmol/L, respectively. Under normoxia condition, clone formation quantity was significantly lower in CMNa group than that of control group. Compared to normoxia condition, clone formation quantity was significantly lower in hypoxia condition. Under hypoxia condition, compared to control group, cell apoptosis rate and G1-phase ratio increased significantly; S-phase ratio decreased significantly; expressions of stimulated apoptosis protein (Caspase 3/8/9) and Bax increased; inhibited apoptosis protein (Bc1-2) decreased; expression of cell cycle-related protein (Cyclin D1) decreased; and expression of P16 increased in CMNa group. Conclusion CMNa has specific enhancing effect on radiosensitivity of SH-SY5Y under hypoxia condition.

Key words: glycidiazale sodium, neuroblastoma, radiosensitivity