Silencing BAG-2 Gene Inhibits The Cell Proliferation Of Human Lung Carcinoma A549 Cells

Lung cancer is one of the common primary malignant tumors, with the highest incidence of cancer in the world. About 25% of the lung primary malignant tumor is lung adenocarcinoma, and the incidence rate is rising in recent years. Based on our earlier analysis on lung adenocarcinoma using subcellular proteomics, the current investigation focused on the aberrant expression of the protein BAG-2 in lung carcinoma A549 cells, and investigated the biological function of BAG-2 in cancer.Aims:To observe the biological effects of BAG-2 gene silencing using siRNA on cell cycle and proliferation of lung carcinoma A549 cells; to investigate if BAG-2 siRNA affects the proliferation of A549 cells through degrading cyclins by ubiquitin-proteasome pathway.Methods:Western blotting was used to detect the knock-down effects of BAG-2 protein expression after siRNA transfection for 0,24 and 48 h; Flow cytometry was used to measure the effects of BAG-2 siRNA on the proliferation of A549 cells by labelling with CFSE dye; and the expression level of cyclins were detected after transfecting BAG-2 siRNA for 48 h to assess the influence of BAG-2 on cell cycle.Results:After transfecting BAG-2 siRNA in A549 cells, the protein level of BAG-2 was significantly knocked down, but the cell cycle has no change as compared with control cells; the cell proliferation of A549 was slowed down after transfecting BAG-2 siRNA for 48 h; the expressions of cyclin Blwas down-regulated in A549 cells with BAG-2 siRNA transfection for 48 h.Conclusions:As the aberrant expression of BAG-2 as a target, silencing the gene expression could inhibit the proliferation of human lung carcinoma A549 cells. By functional analysis, we speculate that BAG-2 may regulate the expression of cyclins to inhibit cell proliferation through ubiquitin-proteasome pathway.