RESUMO
Objective To explore the effect and molecular mechanism of N-myc downstream regulated gene 1 (NDRG1) on transforming growth factor-beta (TGF-β)-induced epithelial-mesenchymal transition (EMT) in human lung cancer cells.Methods Lung cancer A549 cells were transfected with NDRG1 overexpressed vector,and then treated with 5 μg/L TGF-β1.The abilities of invasion were detected by Transwell assay.The expressions of NDRG1 mRNA and protein were analyzed by teal-time reverse transcription polymerase chain reaction (RT-PCR) were examined with Western blot.The expressions of EMT-associated markers E-cadherin and Vimentin,and EMT-associated signaling molecules Snail,AKT and Smad were detected with Western blot.Results We found that TGF-β1 treatment could induce morphological alteration of A549 cells from epithelial morphology to mesenchymal morphology.TGF-β1 significantly increased the migration of A549 cells,and increased the expression of mesenchymal maker vimentin and decreased epithelial marker E-cadherin.More importantly,overexpression of NDRG1 significandy reversed the effects of TGF-β1 on A549 cells.Moreover,NDRG1 significandy decreased the levels of phospho-AKT,and suppressed the expression of EMT-related transcription factor Snail.Conclusions NDRG1 could reverse the effects of TGF-β1 on EMT in A549 cells,by which mechanism is related to reduction of the expressions of phospho-AKT and Snail.
RESUMO
Objective To investigate the effect of over-expressed macrophage migration inhibitory factor (MIF) on epithelial-mesenchymal transition (EMT) in human cervical carcinoma SiHa cells.Methods Recombinant eukaryotic expression plasmid liposome enhanced transfection of green fluorescent protein gene (pEGFP-N1)-MIF was constructed and then transfected into human cervical cancer SiHa cells.Experimental cells were classified into three groups (SiHa-pEGFP-N1-MIF,SiHa-pEGFP-N1,and SiHa).Western blot was used to detect the expression of MIF protein,and the expressions of EMT-related markers such as E-cadherin and vimentin in SiHa cells were determined before and after transfection.Results The eukaryotic expression vector pEGFP-N1-MIF significantly increased the expression of MIF protein in SiHa cells (P ＜ 0.05),and after overexpression of MIF gene in SiHa cells,the expression of E-cadherin protein in SiHa-pEGFP-N1-MIF group was significantly lower than that in control groups (P ＜0.05),while the expression of vimentin in SiHa-pEGFP-N1-MIF group was significantly higher than that in control groups (P ＜ 0.05).Conclusions Overexpression of MIF in cervical cancer SiHa cells can promote the EMT occurrence.