雷公藤甲素通过STAT3/PD-L1通路介导子宫内膜癌KLE细胞DNA损伤诱导细胞凋亡的作用机制研究

Study on the Mechanism of Triptolide Mediated DNA Damage and Apoptosis of Endometrial Carcinoma KLE Cells through STAT3/PD-L1 Pathway

目的:探讨雷公藤甲素对子宫内膜癌KLE细胞DNA损伤及细胞凋亡的影响,以及信号传导及转录激活因子3(STAT3)/程序性死亡受体-配体1(PD-L1)通路在其中发挥的作用。方法:将对数期人子宫内膜癌KLE细胞分为对照组、雷公藤甲素组、激活剂+雷公藤甲素组、激活剂组,并进行相应处理。24 h后,观察细胞核形态,噻唑蓝(MTT)法检测细胞增殖抑制率,流式细胞术检测细胞凋亡率及细胞周期,Western blotting法检测磷酸化组蛋白H2AX(γH2AX)、STAT3、p-STAT3、干扰素调节因子1(IRF-1)、PD-L1蛋白表达水平。结果:雷公藤甲素组和激活剂+雷公藤甲素组KLE细胞核增大,激活剂组和对照组细胞核形态相似。与雷公藤甲素组比较,激活剂+雷公藤甲素组24、48、72 h细胞增殖抑制率及细胞凋亡率均明显降低(P<0.05)。与雷公藤甲素组比较,激活剂+雷公藤甲素组、激活剂组S期细胞百分率、γH2AX蛋白相对表达量均明显降低(P<0.05),G2/M期细胞百分率、p-STAT3、IRF-1、PD-L1蛋白相对量均明显升高(P<0.05)。结论:雷公藤甲素通过诱导子宫内膜癌KLE细胞DNA损伤促进细胞凋亡,发挥抑瘤作用,可能是通过调控STAT3/PD-L1通路发挥作用。

Objective: To explore the effect of triptolide on DNA damage and apoptosis of endometrial carcinoma Kle cells, and the role of signal transduction and transcription activator 3(STAT3)/programmed death receptor ligand 1(PD-L1) pathway. Method: The logarithmic stage of human endometrial cancer KLE cells were divided into control group(DMSO), triptolide group activator + triptolide group, and activator group. After24 hours, the nucleus morphology was observed, the proliferation inhibition rate of KLE cells was detect by thiazole blue(MTT), the apoptosis rate and cell cycle were detected by flow cytometry, the relative protein expression levels of γH2AX, STAT3, p-STAT3, IRF-1, and PD-L1 were detected by Western bloting. Results: The nucleus morphology of the triptolide group and the activator + triptolide group increased, and the nucleus morphology of the activator group and the control group were similar. Compared with the triptolide group, the cell proliferation inhibition rate and the apoptosis rate of the activator + triptolide group were significantly lower at 24, 48 and72 hours(P<0.05). Compared with the triptolide group, the percentage of S phase cells and the relative expression level of γH2AX protein in the activator + triptolide group and the activator group decreased significantly(P<0.05), and the percentage of cells in G2/M phase, p-STAT3, IRF-1, PD-L1 The relative protein level increased significantly(P<0.05). Conclusion: Triptolide can promote apoptosis and inhibit tumor by inducing DNA damage in endometrial carcinoma Kle cells, possibly by regulating STAT3/PD-L1 pathway.