【摘要】 目的观察转录因子信号转导与激活因子3(STAT3)活化在人肝癌细胞低氧诱导因子-1α(HIF-1α)表达中的作用,探讨柴胡皂甙d是否可以通过影响STAT3/HIF-1α信号通路参与调节人肝癌细胞的HIF-1α表达,以进一步阐释其抗肿瘤作用的机制。方法①以AG-490抑制STAT3磷酸化后观察氯化钴模拟缺氧条件下人肝癌SMMC-7721细胞中p-STAT3、HIF-1α蛋白及STAT3和HIF-1α的mRNA水平。②应用不同浓度的柴胡皂甙d作用于氯化钴模拟缺氧下培养的人肝癌SMMC-7721细胞,干预24h后,分别检测肝癌细胞中p-STAT3、HIF-1α蛋白及STAT3和HIF-1α的mRNA水平。结果①AG-490干预细胞后,细胞中p-STAT3的表达明显降低,而HIF-1α的蛋白水平随之出现显著下降,各组STAT3和HIF-1α的mRNA水平没有明显改变。②柴胡皂甙d抑制了氯化钴模拟缺氧条件下p-STAT3蛋白的表达,并呈现出剂量依赖性,HIF-1α的蛋白水平随柴胡皂甙d的浓度呈下降趋势,各处理组STAT3和HIF-1α的mRNA水平没有明显改变。结论转录因子STAT3的活化参与了缺氧条件下人肝癌细胞HIF-1α表达的调节,柴胡皂甙d可以抑制缺氧条件下肝癌细胞HIF-1α的表达,部分机制是通过影响STAT3的活化来实现的,柴胡皂甙d可以通过抑制HIF-1α的表达发挥其抗肿瘤作用。更多还原

【Abstract】 【Objective】 To observe the role of activated STAT3 in the expression of HIF-1α in hepatocellular carcinoma cells,and investigate whether via working through STAT3/HIF-1α pathway Saikosaponin d is involved in inhibiting the expression of HIF-1α to further elaborate its antitumor effect.【Methods】 ①After applying AG-490 to block the phosphorylating of STAT3,examine the expression of p-STAT3,HIF-1α protein levels and STAT3,HIF-1α mRNA levels in hepatocellular carcinoma SMMC-7721 cell line cultured under hypoxic conditions simulated by cobalt chloride.②Impose the hepatocellular carcinoma SMMC-7721 cells cultured under hypoxic conditions simulated by cobalt chloride with different concentrations of Saikosaponin d and detect the expression of p-STAT3,HIF-1α protein levels and STAT3,HIF-1α mRNA levels.【Results】 ①AG-490 drastically inhibited the phosphorylating of STAT3 while the HIF-1α protein levels decreased apparently.However,no significant variations of STAT3 and HIF-1α mRNA levels could be seen among all the groups.②Saikosaponin d blocked the phosphorylating of STAT3 in a dose-dependent pattern in SMMC-7721 cells cultured under hypoxic conditions simulated by cobalt chloride.In terms of HIF-1α,its protein levels decline in contrast to the increase in the concentrations of Saikosaponin d.Also,both STAT3 and HIF-1α didn’t change at mRNA levels in all the groups.【Conclusion】 The activation of transcription factor STAT3 is proved to be involved in the expression of HIF-1αin hepatocellular carcinoma cells under hypoxic conditions.And Saikosaponin d exhibiting its antitumor effect by inhibiting the expression of HIF-1α induced by hypoxia in hepatocellular carcinoma cells partially works through blocking the activating of STAT3.更多还原