TGF-β、内质网应激cross-talk在肺癌细胞上皮间质转化机制中的作用

The action mechanism of TGF-βand endoplasmic reticulum stress cross-talk on the epithelial-mesenchymal transition in lung cancer cells

目的:探讨转移生长因子β(TGF-β)和内质网应激(ER stress)cross-talk在肺癌细胞上皮间质转化(EMT)中的关系。方法:采用TGF-β1(0、2.5、5、10 ng/mL)作用肺癌细胞A549,观察A549细胞EMT发生情况;另将细胞A549分为对照组、TGF-β1组(10 ng/mL)、4-PBA组(10 mM)、联合组(10 ng/mL TGF-β1+10 mM 4-PBA),transwell实验观察细胞侵袭能力,采用Western blot、RT-PCR检测EMT、ER stress、侵袭相关基因蛋白水平。结果:与对照组相比,TGF-β1(2.5、5、10 ng/mL)处理下A549细胞EMT现象明显,TGF-β1组细胞侵袭数目、GRP78、XBP-1s、p-Akt/Akt、p-PI3K/PI3K蛋白水平升高,GRP78、XBP-1s、N-cadherin、vimentin、Snail1和Snail2 mRNA水平升高,E-cadherin mRNA水平降低。与对照组相比,4-PBA组细胞侵袭数目、GRP78、XBP-1s、p-Akt/Akt、p-PI3K/PI3K蛋白水平降低,GRP78、XBP-1s、N-cadherin、vimentin、Snail1和Snail2 mRNA水平降低,E-cadherin mRNA水平升高。与TGF-β1组相比,联合组细胞侵袭数目、GRP78、XBP-1s、p-Akt/Akt、p-PI3K/PI3K蛋白水平降低,GRP78、XBP-1s、N-cadherin、vimentin、Snail1和Snail2 mRNA水平降低,E-cadherin mRNA水平升高。结论:TGF-β1可诱导A549细胞EMT,可能是通过介导ER stress发挥促EMT作用。

Objective To explore the cross-talk relationship between transforming growth factorβ(TGF-β)and endoplasmic reticulum stress(ER stress)in the epithelial-mesenchymal transition(EMT)of lung cancer cells.Methods The lung cancer cells A549 were treated with TGF-β1(0,2.5,5,10 ng/mL).The occurrence of EMT in A549 cells was observed.A549 cells were divided into control group,TGF-β1 group(10 ng/mL),4-PBA group(10 mM)and combination group(10 ng/mL TGF-β1+10 mM 4-PBA).The ability of cells invasion was observed by transwell assay.Protein levels of EMT,ER stress and invasion related genes were detected by Western blot and RT-PCR.Results Compared with control group,incidence of EMT was significantly higher in A549 cells treated with TGF-β1(2.5,5,10 ng/mL),number of invasion cells,protein levels of GRP78,XBP-1s,p-Akt/Akt and p-PI3K/PI3K were increased in TGF-β1 group,levels of GRP78,XBP-1s,N-cadherin,vimentin,Snail1 and Snail2 mRNA were increased,and level of E-cadherin mRNA was decreased.Compared with control group,number of invasion cells,protein levels of GRP78,XBP-1s,p-Akt/Akt and p-PI3K/PI3K were decreased in 4-PBA group,levels of GRP78,XBP-1s,N-cadherin,vimentin,Snail1 and Snail2 mRNA were decreased,and level of E-cadherin mRNA was increased.Compared with TGF-β1 group,number of invasion cells,protein levels of GRP78,XBP-1s,p-Akt/Akt and p-PI3K/PI3K were decreased in combination group,levels of GRP78,XBP-1s,N-cadherin,vimentin,Snail1 and Snail2 mRNA were decreased,and level of E-cadherin mRNA was increased.Conclusion TGF-β1 can induce EMT in A549 cells,which may promote EMT by mediating ER stress.