转染白细胞介素18基因通过下调多药耐药基因表达增强顺铂对C6胶质瘤细胞毒作用

Transfection of IL 18 gene enhances cytotoxicity of cisplatin on C6 glioma cells by reducing Mdr1 expression

摘要:

目的  探讨转染白细胞介素18（IL18）基因对大鼠C6胶质瘤细胞顺铂化疗敏感性的影响及可能的作用机制。方法  体外培养转染IL18基因的C6/IL18细胞株和未转染的C6细胞系，MTT法观察顺铂对两类肿瘤细胞的抑制率；流式细胞术检测顺铂作用后转染及未转染肿瘤细胞的凋亡率；反转录PCR及蛋白质印迹法（Western blot）检测转染细胞内多药耐药基因（Mdr1）和拓扑异构酶TopoⅡα的mRNA水平和蛋白质水平的表达变化。 结果  顺铂对转染IL18基因的胶质瘤细胞株的抑制率明显高于未转染细胞（P <0.05），半数抑制浓度分别为29.66μg/ml和55.49μg/ml；流式细胞术显示顺铂作用后的转染细胞凋亡增多（P <0.05）；反转录PCR及Western blot显示转染细胞的Mdr1基因表达显著下降，TopoⅡα基因表达无明显变化。结论  转染IL18基因能够下调多药耐药基因Mdr1的表达，增强顺铂对大鼠C6胶质瘤细胞的毒作用。

Abstract:

Objective To explore the effect of transfection of interleukin 18 (IL 18) on sensitivity of rat C6 glioma cells to cisplatin chemotherapy and the possible mechanism. Methods C6 cells with and without transfection of IL 18 (C6/IL18 cells and C6 cells) were cultured in vitro. The growth inhibition ratios of both types of glioma cells were measured by MTT assay, when treated with cisplatin at various concentrations. Cell apoptosis was detected by flow cytometry after being treated with 50% inhibition concentration of cisplatin. The levels of mRNA and protein of Mdr1 and TopoⅡα were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Results Upon cisplatin treatment, the ratio of growth inhibition was significantly higher in the C6/IL18 cells than that in the C6 cells (P < 0.05), the 50% inhibition concentration of cisplatin was 29.66 μg/ml and 55.49 μg/ml respectively. The apoptosis ratio of the C6/IL18 cells was higher than that of the C6 cells after treatment with cisplatin (P < 0.05). In the C6/IL18 cells, the expressions of Mdr 1 was markedly down-regulated identified by RT-PCR and Western blot, but the expressions of TopoⅡα had no significant differences. Conclusions Transfection with IL 18 significantly reduces the expressions of Mdr1, then strengthens the chemo-sensitivity of C6 glioma cells to cisplatin.