三叶青总黄酮通过STAT3信号通路诱导膀胱癌细胞凋亡

Total flavonoids of trifolium induces apoptosis of bladder cancer cells through STAT3 signal pathway

目的 探讨体外使用三叶青总黄酮(TFTH)对膀胱癌细胞增殖、凋亡的影响及其对信号转导与转录激活因子(STAT)3信号通路的作用机制。方法 对人膀胱癌BIU-87细胞进行体外培养,将不同浓度TFTH加入培养基对BIU-87细胞进行培养,通过细胞对数试剂盒(CCK)-8试验分别检测不同浓度TFTH(0、20、50、100μg/ml)组作用24、48 h后对细胞增殖的影响;流式细胞技术分析不同浓度TFTH作用24、48 h后对细胞凋亡率的影响;Western印迹检测不同浓度TFTH对Janus蛋白酪氨酸激酶(JAK)2、STAT3、B细胞淋巴瘤(Bcl)-2相关X基因(Bax)、血管内皮生长因子(VEGF)和转化生长因子(TGF)-β1蛋白表达的影响。结果 CCK-8检测结果显示,不同浓度TFTH处理BIU-87细胞24或48 h后,对癌细胞增殖均有抑制作用(P<0.01);细胞凋亡检测结果显示,不同浓度TFTH处理BIU-87细胞24或48 h后,均有诱导癌细胞凋亡作用(P<0.01),且TFTH对细胞增殖或凋亡呈剂量时间依赖性;Western印迹结果显示,不同浓度TFTH处理后的BIU-87细胞,其JAK2、STAT3、VEGF和TGF-β1蛋白表达均明显降低,Bax蛋白表达明显升高,且呈剂量依赖性(P<0.05)。结论 TFTH可通过体外抑制膀胱癌BIU-87细胞JAK2/STAT3信号通路表达,使JAK2、STAT3、TGF-β1、VEGF蛋白表达减少,Bax蛋白表达增加,从而抑制膀胱癌BIU-87细胞增殖和诱导细胞凋亡。

Objective To investigate the effects of total flavonoids of trifolium(TFTH)on the proliferation and apoptosis of bladder cancer cells in vitro and the mechanism of its action on the signal transduction and activator of transcription(STAT)3 signaling pathway.Methods Human bladder cancer BIU-87 cells were cultured in vitro,and different concentrations of TFTH were added to the culture medium to culture BIU-87 cells.The effects of different concentrations of TFTH(0,20,50,100μg/ml)groups on cell proliferation after 24 and 48 h were detected by cell logarithm kit(CCK)-8 test.Flow cytometry was used to analyze the effect of different concentrations of TFTH on apoptosis rate after 24 and 48 h.The effects of different concentrations of TFTH on the expressions of Janus protein tyrosine kinase(JAK)2,STAT3,B-cell lymphoma(Bcl-2)-associated X gene(Bax),vascular endothelial growth factor(VEGF)and transforming growth factor(TGF)-β1 were detected by Western blotting.Results CCK-8 detection showed that TFTH at different concentrations inhibited the proliferation of BIU-87 cells for 24 or 48 h(P<0.01).The results of apoptosis detection showed that TFTH at different concentrations could induce apoptosis of BIU-87 cells for 24 or 48 h(P<0.01),and TFTH had a dose-time dependent effect on cell proliferation or apoptosis.Western blotting results showed that the protein expressions of JAK2,STAT3,VEGF and TGF-β1 were significantly decreased in BIU-87 cells treated with different concentrations of TFTH,while the protein expression of Bax was significantly increased in a dose-dependent manner(P<0.05).Conclusions TFTH could inhibit the expression of JAK2/STAT3 signaling pathway in bladder cancer BIU-87 cells in vitro,reduce the expressions of JAK2,STAT3,TGF-β1 and VEGF protein,and increase the expression of Bax protein,thus inhibiting the proliferation of bladder cancer BIU-87 cells and inducing cell apoptosis.