桂皮醛通过PI3K/Akt信号通路抑制TGF-β_1诱导的结肠癌细胞LoVo上皮间质转化

Cinnamaldehyde Inhibits TGF-β_1 Induced Epithelial-mesenchymal Transition of Human Colorectal Carcinoma Cells LoVo via PI3K/Akt Signaling Pathway

目的:探讨桂皮醛对转化生长因子-β_1(Transforming growth factor-β_1,TGF-β_1)诱导的结肠癌LoVo细胞增殖、侵袭及上皮间质转化(epithelial-mesenchymal transition,EMT)的影响及其与磷酯酰肌醇3激酶/蛋白激酶B(PI3K/Akt)信号通路的关系。方法:通过TGF-β_1诱导结肠癌细胞株LoVo发生上皮间质转化,使用桂皮醛(0,20,40,80 mg·L-1)干预由TGF-β_1诱导的LoVo细胞的增殖,采用四甲基偶氮唑蓝(MTT)比色法检测桂皮醛对TGF-β_1诱导的细胞增殖能力的影响。转移小室(transwell)侵袭实验检测细胞侵袭能力变化。蛋白质免疫印迹法(Western blot)检测E-钙黏蛋白(E-cadherin),N-钙黏蛋白(N-cadherin),波形蛋白(Vimentin)及PI3K/Akt信号通路关键蛋白的表达。采用PI3K/Akt抑制剂LY290004来验证桂皮醛通过PI3K/Akt信号通路抑制TGF-β_1诱导的EMT。结果:与空白组比较,桂皮醛能有效抑制TGF-β_1诱导的增殖及侵袭能力(P<0.01),显著增加E-cadherin的表达,抑制N-cadherin,Vimentin及TGF-β_1刺激的p-Akt和p85的表达(P<0.01);同时通过抑制PI3K/Akt信号通路的激活逆转TGF-β_1诱导的EMT(P<0.01)。结论:桂皮醛可通过调节PI3K/Akt信号通路抑制TGF-β_1诱导的结肠癌细胞LoVo的上皮间质转化,降低其侵袭能力。

Objective： To investigate the effect of cinnamaldehyde on transforming growth factor-β_1（ TGF-β_1）-induced proliferation,metastasis and epithelial-mesenchymal transition（ EMT） of human colorectal carcinoma cells LoVo and explore its relationship with phosphatidylinositol 3 kinase/protein kinase B（ PI3K/Akt）signaling pathway. Method： TGF-β_1was used to induce EMT of human colorectal carcinoma cells LoVo,and then different concentrations of cinnamaldehyde（ 0,20,40,80 mg·L-1） were used to intervene the TGF-β_1-induced cells proliferation. The effect of cinnamaldehyde on cell proliferation was measured by methylthiazolyldiphenyltetrazolium bromide（ MTT） assay. Transwell assay was used to observe the changes in invasive ability of cells,and Western blot was used to analyze the expression levels of epithelial phenotype marker protein E-cadherin,Ncadherin,Vimentin and key protein of phosphatidylinositol-3-kinases/proteinkinase B（ PI3K/Akt） signaling pathway. PI3K/Akt inhibitor LY290004 was used to verify the cinnamaldehyde effect in inhibiting TGF-β_1-induced EMT through the PI3K/Akt signaling pathway. Result： As compared with blank controls, cinnamaldehyde effectively inhibited TGF-β_1-induced proliferation and invasion ability（ P〈0. 01）,significantly increased the expression of E-cadherin,decrease the expression of N-cadherin,Vimentin,stimulated by TGF-β_1（ P〈0. 01）,and meanwhile,it could reverse the expression TGF-β_1-induced EMT through inhibiting the activation of the PI3K/Akt signaling pathway（ P〈0. 01）. Conclusion： Cinnamaldehyde can inhibit TGF-β_1-induced proliferation,metastasis of colorectal carcinoma cells LoVo,and the mechanism may be associated with PI3K/Akt signaling pathway.