Background:Epithelial-mesenchymal transition(EMT) is believed to be the critical process in malignant tumor invasion and metastases,and has a great influence on improving the survival rate in non-small-cell lung cance...Background:Epithelial-mesenchymal transition(EMT) is believed to be the critical process in malignant tumor invasion and metastases,and has a great influence on improving the survival rate in non-small-cell lung cancer(NSCLC) patients.Recent studies suggested that eukaryotic initiation factor 5A-2(eIF5A-2) might serve as an adverse prognostic marker of survival.We detected eIF5A-2 in NSCLC A549 cells,and found that the invasive capability correlates with the eIF5A-2 expression.Methods:Transforming growth factor(TGF)-β1 was used to induce EMT in A549 cells.Western blotting,immunofluorescence,wound healing assay,and transwell-matrigel invasion chambers were used to identify phenotype changes.Western blotting was also used to observe changes of the expression of eIF5A-2.We down-regulated the eIF5A-2 expression using an eIF5A-2 siRNA and identified the phenotype changes by western blotting and immunofluorescence.We tested the change of migration and invasion capabilities of A549 cells by the wound healing assay and transwell-matrigel invasion chambers.Results:After stimulating with TGF-β1,almost all A549 cells changed to the mesenchymal phenotype and acquired more migration and invasion capabilities.These cells also had higher eIF5A-2 protein expression.Down-regulation of eIF5A-2 expression with eIF5A-2 siRNA transfection could change the cells from mesenchymal to epithelial phenotype and decrease tumor cell migration and invasive capabilities significantly.Conclusions:The expression of eIF5A-2 was up-regulated following EMT phenotype changes in A549 cells,which correlated with enhanced tumor invasion and metastatic capabilities.Furthermore,in the A549 cell line,the process of EMT phenotype change could be reversed by eIF5A-2 siRNA,with a consequent weakening of both invasive and metastatic capabilities.展开更多
The initiation factor elF5A in Trichomonas vaginalis （TvelF5A） is previously shown to undergo hypusination, phosphorylation and glycosylation. Three different pI isoforms of TvelF5A have been reported. The most acid...The initiation factor elF5A in Trichomonas vaginalis （TvelF5A） is previously shown to undergo hypusination, phosphorylation and glycosylation. Three different pI isoforms of TvelF5A have been reported. The most acidic isoform （pI 5.2） corresponds to the precursor TvelF5A, whereas the mature TvelF5A appears to be the most basic isoform （pI 5.5）. In addition, the intermediary isoform （pI 5.3） is found only under polyamine-depleted conditions and restored with exogenous putrescine. We propose that differences in PI are due to phosphorylation of the TvelF5A isoforms. Here, we have identified phosphorylation sites using mass spectrometry. The mature TvelF5A contains four phosphorylated residues （$3, T55, T78 and T82）. Phosphorylation at $3 and T82 is also identified in the intermediary TvelF5A, while no phosphorylated residues are found in the precursor TvelF5A. It has been demonstrated that elF5A proteins from plants and yeast are phosphorylated by a casein kinase 2 （CK2）. Interestingly, a gene encoding a protein highly similar to CK2 （TvCK2） is found in T. vaginalis, which might be involved in the phosphorylation of TvelF5A in T. vaginalis.展开更多
基金Project supported by the Natural Science Fundation of Ningbo (No. 2011A610052)the Zhejiang Provincial Natural Science Fundation (No. LY12H16002) of China
文摘Background:Epithelial-mesenchymal transition(EMT) is believed to be the critical process in malignant tumor invasion and metastases,and has a great influence on improving the survival rate in non-small-cell lung cancer(NSCLC) patients.Recent studies suggested that eukaryotic initiation factor 5A-2(eIF5A-2) might serve as an adverse prognostic marker of survival.We detected eIF5A-2 in NSCLC A549 cells,and found that the invasive capability correlates with the eIF5A-2 expression.Methods:Transforming growth factor(TGF)-β1 was used to induce EMT in A549 cells.Western blotting,immunofluorescence,wound healing assay,and transwell-matrigel invasion chambers were used to identify phenotype changes.Western blotting was also used to observe changes of the expression of eIF5A-2.We down-regulated the eIF5A-2 expression using an eIF5A-2 siRNA and identified the phenotype changes by western blotting and immunofluorescence.We tested the change of migration and invasion capabilities of A549 cells by the wound healing assay and transwell-matrigel invasion chambers.Results:After stimulating with TGF-β1,almost all A549 cells changed to the mesenchymal phenotype and acquired more migration and invasion capabilities.These cells also had higher eIF5A-2 protein expression.Down-regulation of eIF5A-2 expression with eIF5A-2 siRNA transfection could change the cells from mesenchymal to epithelial phenotype and decrease tumor cell migration and invasive capabilities significantly.Conclusions:The expression of eIF5A-2 was up-regulated following EMT phenotype changes in A549 cells,which correlated with enhanced tumor invasion and metastatic capabilities.Furthermore,in the A549 cell line,the process of EMT phenotype change could be reversed by eIF5A-2 siRNA,with a consequent weakening of both invasive and metastatic capabilities.
基金supported by grants from Consejo Nacional de Ciencia y Tecnolog'a(CONACyTGrant No.83808)Mexico awarded to MEAS+1 种基金Instituto de Ciencia y Tecnolog'a del Distrito Federal(ICyTDFGrant No.221/2011,328/2011,18/2011 and 321/2009)
文摘The initiation factor elF5A in Trichomonas vaginalis （TvelF5A） is previously shown to undergo hypusination, phosphorylation and glycosylation. Three different pI isoforms of TvelF5A have been reported. The most acidic isoform （pI 5.2） corresponds to the precursor TvelF5A, whereas the mature TvelF5A appears to be the most basic isoform （pI 5.5）. In addition, the intermediary isoform （pI 5.3） is found only under polyamine-depleted conditions and restored with exogenous putrescine. We propose that differences in PI are due to phosphorylation of the TvelF5A isoforms. Here, we have identified phosphorylation sites using mass spectrometry. The mature TvelF5A contains four phosphorylated residues （$3, T55, T78 and T82）. Phosphorylation at $3 and T82 is also identified in the intermediary TvelF5A, while no phosphorylated residues are found in the precursor TvelF5A. It has been demonstrated that elF5A proteins from plants and yeast are phosphorylated by a casein kinase 2 （CK2）. Interestingly, a gene encoding a protein highly similar to CK2 （TvCK2） is found in T. vaginalis, which might be involved in the phosphorylation of TvelF5A in T. vaginalis.
