|Other Titles||Mechanism of Poly(I∶C)-induced apoptosis in lung adenocarcinoma A549 cells|
|Citation||国际肿瘤学杂志. 2017, 44(5), 321-326.|
|Abstract||目的 研究多聚肌苷酸-多聚胞苷酸[Poly(I:C)]对肺腺癌A549细胞活力的影响,探讨Poly(I:C)诱导A549细胞凋亡机制.方法 用Poly(I:C)和脂质体3000转染A549细胞,采用四甲基偶氮唑蓝(MTT)检测细胞存活力;采用流式细胞术检测细胞凋亡;Western blotting用于检测凋亡相关蛋白、实时定量PCR检测细胞因子β干扰素(IFN-β)、趋化因子-10(CXCL-10)的表达.使用pan-caspase抑制剂Z-VAD-FMK和caspase-8特异性抑制剂Z-IETD-FMK抑制凋亡蛋白后,观察Poly(I:C)诱导A549细胞凋亡的变化.RNA干扰实验敲低黑色素瘤分化相关抗原5(MDA5)、维甲酸诱导基因Ⅰ(RIG-Ⅰ)的表达,进行上述指标的检测.结果 200 ng/ml Poly(I:C)转染后,肺腺癌A549细胞的存活率为74.92％&#177;6.24％,较转染前(95.32％&#177;3.05％)降低(t=2.883,P=0.041).100、200、400 ng/ml的Poly(I:C)诱导A549细胞凋亡率分别为9.97％&#177;0.88％、23.63％&#177;1.41％、32.57％-&#177;2.39％,与对照组(0.74％&#177;0.15％)相比,差异均有统计学意义(t =4.489,P=0.002;t=11.616,P=0.000;t=16.932,P=0.000).此外,死亡受体途径蛋白如TNF相关的凋亡诱导配体(TRAIL)、cleaved-caspase-8、cleaved-caspase-3明显升高,同时MDA5/RIG-Ⅰ通路激活以及1FN-β、CXCL-10的表达上调.pan-caspase抑制剂Z-VAD-FMK、caspase-8抑制剂Z-IETD-FMK使细胞凋亡率分别降至3.17％&#177;0.66％、5.35％&#177;0.64％,与不加抑制剂(15.87％ &#177;0.93％)相比,差异有统计学意义(t=8.643,P=0.001;=6.824,P=0.002).RIG-Ⅰ、MDA5敲低后,Poly(I:C)诱导的TRAIL、IFN-β、CXCL-10表达下调.结论 Poly(I:C)能降低A549细胞的存活率,通过激活死亡受体途径诱导A549细胞的凋亡,并且MDA5/RIG-Ⅰ可能参与了该凋亡途径,此过程可能与IFN-β、CXCL-10有关.|
Objective To study the effects of Poly(I:C) on lung adenocarcinoma A549 cells viability and illuminate the mechanism of Poly (I:C)-induced apoptosis in A549 cells.Methods A549 cells were transfected with the complex of Poly(I:C) and lipofectamine 3000.The viability of A549 cells was tested by methyl thiazolyl tetrazolium (MTF) method.The apoptotic cells were tested by flow cytometry.The caspase proteins were tested by Western blotting and the expressions of interferon-β (IFN-β) and CXCL-10 were assayed by real-time PCR.After employing the pan-caspase inhibitor Z-VAD-FMK and caspase-8 inhibitor Z-IETD-FMK,the variation of Poly (I:C) proapoptosis in A549 cells was observed.RNA interfering experiments were employed to knock down melanoma differentiation related antigen 5 (MDA5) or retinoic acidinduced gene Ⅰ (RIG-Ⅰ),and the above indexes were tested.Results The viability of A549 cells was significantly reduced to 74.92％ &#177;--6.24％ after 200 ng/ml Poly (I:C) transfection compared with that before transfection (95.32％ &#177; 3.05％,t =2.883,P =0.041).The apoptotic rates induced by 100,200,400 ng/ml Poly(I:C) were 9.97％-&#177; 0.88％,23.63％-&#177; 1.41％,32.57％-&#177; 2.39％,respectively.All of them were higher than that in the control group (0.74％-&#177; 0.15％),with significant differences (t =4.489,P =0.002;t =11.616,P =0.000;t =16.932,P =0.000).Besides,the death receptor pathway proteins such as TNF-related apoptosis inducing ligand (TRAIL),cleaved-caspase-8 and cleaved-caspase-3 increased obviously.MDA5/RIG-Ⅰ pathway was also activated dramatically and the expressions of IFN-β,CXCL-10 were significantly up-regulated.The apoptotic rates reduced to 3.17％ &#177; 0.66％,5.35％ &#177; 0.64％ with pancaspase inhibitor Z-VAD-FMK and caspase-8 inhibitor Z-IETD-FMK pretreatment,compared with the control group (15.87％ &#177;0.93％),and the differences were statistically significant (t =8.643,P =0.001;t =6.824,P =0.002).Moreover,the expressions of TRAIL,IFN-β and CXCL-10 induced by Poly (I:C) were inhibited with MDA5 or RIG-Ⅰ depletion.Conclusion Poly(I:C) can reduce the survival rate of A549 cells and promote the apoptosis mainly by activating the death-receptor pathway mediated by MDA5/RIG-Ⅰ probably,which may involve in IFN-β,CXCL-10.
|Appears in Collections:||第一医院|