Pro-apoptotic molecule Noxa mediates etoposide-induced cell death in human neuroblastoma cells / 国际儿科学杂志

ABSTRACT

Objective:To study whether Noxa mediates cell death induced by etoposide in the human neuroblastoma(NB)cells.Methods:NB cells(TB3 and TB8) were treated with different concentrations of etoposide(0, 0.125, 0.25, 0.5 0.75, 1.0 mg/L), and the cell survival was detected by CCK8 assay.After treated with etoposide, NB cells were collected at different time points, then total RNAs were isolated and RT-qPCR was performed to detect the mRNA expression of Noxa.At the same time, the whole cell lysates were extracted and western blot was performed to detect the protein expression of Noxa.In order to evaluated the effect of Noxa on etoposide-induced cell survival, Noxa siRNA was transfected into NB cells, then CCK8 assay was performed.Results:After treatment with different concentrations of etoposide(0.125 mg/L、0.25 mg/L、0.5 mg/L、0.75 mg/L、1.0 mg/L ), the survival rates of TB3 cells were(73.13±8.45)%, (56.18±10.50)%, (33.90±4.17)%, (26.76±6.67)%, (13.49±0.58)%, respectively(compared with the control group, P<0.01); the survival rates of TB8 cells were(71.06±6.96)%, (37.45±0.68)%, (25.53±3.70)%, (20.28±2.75)%, (10.09±2.52)%, respectively(compared with the control group, P<0.01).The mRNA and protein expression of Noxa in NB cells were both increased in a time-dependent manner after treated with etoposide.The siRNA of Noxa could reduce the expression of Noxa in TB3 and TB8 cells after transfection.Treated with etoposide 0.5 mg/L, cell survival rates of TB3 cells tranfected with control siRNA, Noxa siRNA1, Noxa siRNA2 were(45.12±13.58)%, (72.70±21.34)%, (52.08±20.36)%, respectively; cell survival rates of TB8 were(35.52±0.38)%, (63.94±0.10)%, (50.27±1.62)%, respectively(compared with the control group, P<0.01); Treated with etoposide 1.0 mg/L, cell survival rates of TB3 cells tranfected with control siRNA, Noxa siRNA1, Noxa siRNA2 were(13.26±1.84)%, (51.08±2.41)%, (42.80±1.42)%, respectively(compared with the control group, P<0.05); cell survival rates of TB8 were(22.22±3.39)%, (58.00±11.37)%, (40.55±6.94)%, respectively(compared with the control group, P<0.05). Conclusion:Pro-apoptotic molecular Noxa mediated the Etoposide-induced cell death in NB cells(TB3 and TB8) in time and concentration-dependent manner.