Proteomic Analysis of Molecular Mechanisms Involved in TGF-β-Induced Epithelial-Mesenchymal Transition in Human Lung Adenocarcinoma A549 Cells.

Objective: This study aimed to examine the molecular mechanisms involved in transforming growth factor-β (TGF-β)-induced epithelial-mesenchymal transition (EMT) in human lung adenocarcinoma (LUAD) A549 cells.

Methods: Proteins were extracted from cultured human LUAD A549 cells cultured under two conditions: untreated and treated with TGF-β (5 ng/ml) for 48 hours. The expression levels of EMT-related proteins, including E-cadherin, Vimentin, and α- smooth muscle actin, were assessed using western blotting. Proteomic analysis was performed using isobaric tags for relative and absolute quantification combined with two-dimensional liquid chromatography-tandem mass spectrometry. Differentially expressed proteins were subjected to bioinformatics analysis, including functional annotation and interaction network studies.

Results: A total of 122 proteins were identified as differentially expressed between the untreated and TGF-β-treated A549 cells. Of these, 55 proteins were upregulated, while 67 were downregulated following TGF-β treatment. Bioinformatics and interaction network analyses highlighted six proteins-GAPDH, TP53, MAPK1, IGF1, SRC, and MYC-as being closely associated with the EMT in human LUAD.

Conclusion: This study provides new insights into the processes of invasion and metastasis in LUAD by examining the molecular mechanisms underlying TGF-β- induced EMT in A549 cells.