姜黄素作用PTEN/PI3K/AKT通路诱导膀胱癌EJ细胞凋亡

Curcumin induces Apoptosis via PTEN/PI3K/Akt pathway in human bladder careinoma EJ cells

目的:研究姜黄素抗癌作用的分子机制。方法:以人膀胱癌细胞株EJ为模型,采用MTT法、流式细胞术,检测姜黄素对EJ细胞生长和凋亡的影响,并通过Western Blotting法检测姜黄素对EJ细胞PTEN/PI3K/AKT通路凋亡相关蛋白表达的影响。结果:姜黄素以浓度及时间依赖的方式抑制EJ细胞的增殖;流式细胞仪检测发现姜黄素作用于EJ细胞24 h后凋亡率呈剂量依赖性增加。Western Blotting显示50μM姜黄素作用EJ细胞后,PTEN、GSK-3β、C-raf、Bad、caspase-9、caspase-3的活性增强,PARP的裂解增加和Akt、PDK1的表达水平降低。结论:姜黄素能增加EJ细胞PTEN的表达,进而抑制PI3K/Akt信号通路的激活,继之激活下游GSK-3β,caspase-9和Bad等多种促凋亡分子的表达,诱导EJ细胞发生凋亡。该研究表明PTEN/PI3K/Akt信号通路在姜黄素诱导的EJ膀胱癌细胞凋亡中起了重要作用。

Objective： The purpose of our study was to investigate mechanism of action of curcumin in the EJ bladder cancer cell line.Methods： The anti-proliferative potential of curcumin was assessed using MTT assay.Cell apoptosis and the apoptosis-related protein activation of PTEN/PI3K/Akt signaling pathway in EJ cells were evaluated by flow cytometry and Western blotting after treatment with curcumin.Results： Curcumin suppressed the proliferation of EJ cells in a time and dose-dependent manner.Curcumin increased apoptosis rate of EJ cells in a dose-dependent manner.The obvious inhibiting effect of curcumin on EJ cells viability and its apoptosis-inducing effect were observed.Immunoblot showed that the activation of GSK-3β,c-Raf,Bad,caspase-9,caspase-3,cleavage of PARP,upregulation of PTEN and downregulation of PDK1,p-Akt but not total Akt were also found in curcumin（50μM）-treated EJ cells.Conclusion： Our results showed that curcumin may suppress constitutively activated targets of phosphatidylinositol-3-kinases（PI3K） and Akt,whereafter activate GSK-3β,caspase-9 and Bad in the EJ cells through increasing the activation of PTEN,which suggested that PTEN/PI3K/Akt signaling pathway plays an important roles in curcumin-induced apoptosis of EJ bladder cancer cells.