去甲基药、化疗药及TRAIL联合诱导神经母细胞瘤细胞凋亡的研究

Synergistic induction of apoptosis in neuroblastoma cells using a combination of 5-Azacytidine with chemotherapeutic drugs and TRAIL

目的探讨去甲基药5-氮杂胞苷、肿瘤坏死因子相关凋亡诱导配体(TRAIL)及化疗药联合诱导神经母细胞瘤细胞株SH-SY5Y(SY5Y)凋亡的作用及其发生机制。方法应用逆转录-聚合酶链反应(RT-PCR)方法检测5-氮杂胞苷作用前后SY5Y细胞caspase-8的表达;应用四甲基偶氮唑蓝(MTT)比色法及流式细胞仪检测TRAIL、5-氮杂胞苷+TRAIL、5-氮杂胞苷+caspase-8抑制剂zIETD-FMK+TRAIL及5-氮杂胞苷+化疗药+TRAIL对SY5Y细胞生长及凋亡的影响。结果SY5Y细胞不表达caspase-8,5-氮杂胞苷作用1、3、5、7d的SY5Y细胞caspase-8表达逐渐增加。SY5Y细胞对TRAIL不敏感,经5-氮杂胞苷诱导表达caspase-8的SY5Y细胞对TRAIL敏感;化疗药可增强SY5Y细胞对TRAIL的敏感性。结论5-氮杂胞苷可通过上调SY5Y细胞caspase-8表达而逆转SY5Y细胞对TRAIL诱导凋亡的耐受,化疗药可进一步增强TRAIL对SY5Y细胞的诱导凋亡作用。

Objective To study the effect of 5-Azacytidine, tumor necrosis factor related apoptosis inducing ligand （TRAIL） and chemotherapeutic drugs-induced apoptosis in neuroblastoma cells and its possible molecular mechanisms. Methods Caspase-8 mRNA was detected by reverse transcfiptase-polymerase chain reaction. The effects of TRAIL, 5-Azacytidine ＋ TRAIL, 5-Azacytidine ＋ zIETD-FMK ＋ TRAIL and 5-Azacytidine ＋ chemotherapeutic drugs ＋ TRAIL on the growth and apoptosis of SY5Y cells were detected by MTr and flow cytometry. Results Caspase-8 was not detected in SY5Y cells but an increased expression of caspase-8 was found after treatment with 5-Azacytidine. SY5Y cells were not sensitive to TRAIL, but 5-Azacytidine-treated SY5Y cells were sensitive to TRAIL; chemotherapeutic drugs could enhance the sensitivity of TRAIL on SY5Y cells. Conclusion 5-Azacytidine can sensitize SY5Y cells to TRAIL-induced apoptosis and this may be realized by the upregulation of caspase-8. Chemotherapeutic drugs can enhance the effect of TRAIL on SY5Y cells.