食管癌细胞中脂多糖对肿瘤坏死因子α诱导程序性细胞死亡配体1表达的影响

Effects of LPS on TNF-αinduced PD-L1 expression in esophageal cancer cells

目的探讨在食管鳞癌Eca-109细胞中脂多糖(LPS)通过Jak2/Stat3信号通路对肿瘤坏死因子α(TNF-α)诱导程序性细胞死亡配体1(PD-L1)表达的影响及意义。方法2020年5―10月,在TNF-α诱导下,分别使用LPS干预食管鳞癌Eca-109细胞3、6、12、24 h以及不同浓度的LPS干预食管鳞癌Eca-109细胞24 h,应用蛋白质印迹法检测p-Jak2、p-Stat3、PD-L1蛋白表达水平的变化;应用流式细胞技术检测LPS干预对Eca-109细胞凋亡的影响。结果与对照组相比,TNF-α组中p-Jak2蛋白表达(0.79±0.05比0.63±0.11)、p-Stat3蛋白表达(1.48±0.24比0.45±0.08)、PD-L1蛋白表达(0.92±0.15比0.55±0.11)均升高(P<0.05),同时LPS组中凋亡率[(8.20±1.65)%比(4.77±0.15)%]和TNF-α+LPS干预组中凋亡率[(7.63±1.37)%比(4.77±0.15)%]明显升高(P<0.05)。与TNF-α组相比,TNF-α+LPS干预组中p-Jak2蛋白表达(0.46±0.05比0.79±0.05)、p-Stat3蛋白表达(1.10±0.22比1.48±0.24)、PD-L1蛋白表达(0.59±0.08比0.92±0.15)明显降低(P<0.05)。LPS的干预下调p-Jak2、p-Stat3、PD-L1的蛋白表达且呈浓度依赖性。结论LPS通过干预Jak2/Stat3信号通路下调PD-L1的表达水平从而对食管鳞癌Eca-109细胞的免疫逃逸机制进行调控,为进一步探索LPS干预食管癌发生发展的分子机制提供了实验基础。

Objective To investigate the effect of LPS on TNF-αinduced PD-L1 expression in esophageal squamous cell carcinoma Eca-109 cells through Jak2/Stat3 signaling pathway.Methods From May to October 2020,Eca-109 cells of esophageal squamous cell carcinoma were treated with LPS for 3,6,12,24 hours and different concentrations of LPS for 24 hours under TNF-αinduction.The protein levels of p-Jak2,p-Stat3 and PD-L1 were detected by Western blotting.Flow cytometry was used to detect the effect of LPS on apoptosis of ECA-109 cells.Results Compared with the control group,p-jak2(0.79±0.05 vs.0.63±0.11),p-STAT3(1.48±0.24 vs.0.45±0.08),and PD-L1 protein expression(0.92±0.15 vs.0.55±0.11)in the TNF-αgroup were increased(P<0.05).Meanwhile,the apoptosis rate of LPS group[(8.20±1.65)%vs.(4.77±0.15)%]and TNF-α+LPS group[(7.63±1.37)%vs.(4.77±0.15)%]were significantly increased(P<0.05).Compared with TNF-αgroup,p-JAK2 protein expression in TNF-α+LPS intervention group(0.46±0.05 vs.0.79±0.05),p-STAT3 protein expression(1.10±0.22 vs.1.48±0.24)and PD-L1 protein expression(0.59±0.08 vs.0.92±0.15)were significantly decreased(P<0.05).LPS intervention down-regulated the protein expression of p-JAK2,p-STAT3 and PD-L1 in a concentration-dependent manner.Conclusion LPS regulates the immune escape mechanism of esophageal squamous cell carcinoma Eca-109 cells by down-regulating the expression level of PD-L1 through intervening in the Jak2/Stat3 signaling pathway,which provides an experimental basis for further exploration of the molecular mechanism of LPS's intervention in the occurrence and development of esophageal carcinoma.