IFN-γ增强细胞毒类药物对神经母细胞瘤的诱导凋亡作用

Effect of cytotoxic drugs on the induced-apoptosis of neuroblastoma cells enhanced by IFN-γ

目的探讨细胞毒类药物对神经母细胞瘤细胞株SH-SY5Y(SY5Y)细胞的作用及γ-干扰素(IFN-γ)对其抗瘤活性的影响。方法应用逆转录酶-聚合酶链反应(RT-PCR)方法检测IFN-γ作用前后半胱-天冬氨酸蛋白酶8(Caspase8)mRNA的表达;应用流式细胞仪检测细胞毒类药物[阿霉素、肿瘤坏死因子-α(TNF-α)、肿瘤坏死因子相关凋亡诱导配体(TRAIL)]及IFN-γ联合细胞毒类药物对SY5Y细胞的诱导凋亡作用;应用比色法测定Caspase8相对活性。结果SY5Y细胞不表达Caspase8,经IFN-γ作用后Caspase8mRNA表达明显增加。SY5Y细胞对阿霉素相对敏感,对TNF-α和TRAIL不敏感;经IFN-γ预处理后,表达Caspase8的SY5Y细胞对三种细胞毒类药物的诱导凋亡作用敏感并伴随Caspase8活性增高,此作用可被Caspase8抑制剂所阻断。结论IFN-γ通过上调Caspase8表达而增强细胞毒类药物对神经母细胞瘤细胞的诱导凋亡作用。

Objective To explore the effect of cytotoxic drugs on neuroblastoma cell line SY5Y and the influence of γ-interferon（IFN-γ）on the antitumor effects of cytotoxic drugs.Methods The expression of cysteine containing asparate specific protease 8（Caspase 8）mRNA was detected with reverse transcriptase-polymerase chain reaction（RT-PCR）.The effects of cytotoxic drugs [adriamycin,tumor necrosis factor（TNF-α）and tumor necrosis factor related apoptosis inducing ligand（TRAIL）] and IFN-γ combined with cytotoxic drugs on the apoptosis of SY5Y cells were detected with flow cytometry.The relative Caspase 8 activity was measured by colorimetric assay.Results Caspase 8 was undetectable in SY5Y cells with an increased expression of Caspase 8 after treated with IFN-γ.SY5Y cells were sensitive to adriamycin relatively but resistant to TNF-α and TRAIL,while IFN-γ-pretreated SY5Y cells were more sensitive to the cytotoxic drugs with an increase of Caspase 8 activity but the killing effects could be blocked by Caspase 8 inhibitor.Conclusion IFN-γ can sensitize SY5Y cells to cytotoxic drugs-induced apoptosis and this may be realized by the up-regulation of Caspase 8.