Caspase8在实验性神经母细胞瘤细胞凋亡中作用的研究

目的探讨Caspase8表达对肿瘤坏死因子相关凋亡诱导配体（rumor necrosis factor related apoptosis inducing ligand，TRAIL）诱导神经母细胞瘤（neuroblastoma，NB）细胞株SH—SY5Y（SY5Y）细胞凋亡的影响及其发生机制。方法应用RT—PCR方法和免疫组化法检测IFN-γ作用前后SY5Y细胞Caspase8的表达：应用四甲基偶氮唑蓝（MTT）比色法及流式细胞仪（FCM）检测IFN-γ、TRAIL、IFN-γ＋TRAIL及IFN-γ＋Caspase8抑制剂＋TRAIL对SY5Y细胞生长及凋亡的影响。结果SY5Y细胞不表达Caspase8，IFN-γ作用48h后的SYSY细胞Caspase8表达明显增加；SY5Y细胞对TRAIL不敏感，经IFN-γ诱导表达Caspase8的SY5Y细胞对TRAIL敏感，且与TRAIL浓度有关，Caspase8抑制剂可明显降低TRAIL对表达Caspase8的SY5Y细胞的杀伤作用。结论IFN-γ通过诱导Caspase8表达而逆转SY5Y细胞对TRAIL诱导凋亡的耐受。

Experimental study on role of Caspase 8 in apoptosis of neuroblastoma cells

[Objective] To study the expression of Caspase 8 on the effect of TRAIL (tumor necrosis factor related apoptosis inducing ligand) -induced apoptosis in neuroblastoma cells and its possible molecular mechanisms.[Methods] To detect the Caspase 8 expression of SY5Y cells before and after the function of IFN-γby the methods of RT-PCR and immunohistochemistry, and to detect the effect of IFN-γ, TRAIL, IFNγ+TRAIL and IFN-γ+Caspase8 inhibitor +TRAIL on the growth and apoptosis of SY5Y cells by MTT (methylthiazolyl tetrazolium assay) colorimetry and FCM (Flow Cytometry). [Results] SY5Y cells had no expression of Caspase 8. By using of IFN-γfor 48 hours, the expression of Caspase 8 in SY5Y cells increased obviously, SY5Y cells were not sensitive to TRAIL,SY5Y cells expressing Caspase 8 induced by IFN-γwere sensitive to TRAIL which was related to the concentration of TRAIL, Caspase 8 inhibitor could obviously decrease the killing effect of TRAIL on the SY5Y cells expressing Caspase 8. [ Conclusion ] IFN-γ could reverse the resistance of SY5Y cells to the inducing apoptosis function of TRAIL, and its mechanism may be that IFN-γ can up-regulate the expression of Caspase 8 in SY5Y cells.