Mechanical Stretch Promotes Invasion of Lung Cancer Cells via Activation of Tumor Necrosis Factor-alpha

Most of the gas exchange in the human body is carried out by the lungs, and the physiological activities of the lungs are uninterrupted. Due to the deterioration of the external environment, pulmonary cell lesions are common clinical lung diseases. Mechanical cyclic stretching is one kind of bionic technology to observe lung cancer cells. The A549 cell line is the human lung adenocarcinoma cell line derived from a primary lung tumor. This study investigated the effects of mechanical cyclic stretching on A549 cell activity and gene expression profile. Whereas mechanical cyclic stretching had no significant difference in colony formation and cell migration of A549 cells, the cell invasion increased significantly in A549 cells after stretching. In addition, the microarray data showed that mechanical cyclic stretching altered gene expression, induced inflammation of cells, and activation of Wnt/β-catenin and tumor necrosis factor pathways. More importantly, mechanical cyclic stretching activated the expression of tumor necrosis factor-alpha (TNF-α) protein. Therefore, the increase of cell invasion induced by mechanical cyclic stretching might be associated with the activation of TNF-α in human lung adenocarcinoma cells.