The Role Of DJ-1Gene In Lung Cancer And Its Interacting Protein Analysis

Objective To explore the effect of DJ-1gene on biological behaviors of lung cancer cells, RNA interference technology(siRNA) was used to inhibit the expression of DJ-1gene in lung squamous cell carcinoma SK-MES-1and HTB-182cells, and to observe the changes of the biological behaviors of those two types of cells. Moreover, to explore the molecular mechanism that DJ-1functions in lung cancer cells and identify DJ-1interacting proteins, the DJ-1expression plasmid was trans fected into the cells with liposome.Methods A targeted DJ-1siRNA lentiviral vector with a green fluorescent protein (GFP) as a reporter was constructed. The constructed DJ-1siRNA and control-siRNA vectors were infected into SK-MES-1and HTB-182cells as experimental (DJ-1siRNA) and nagtive control (NC) groups, respectively. The DJ-1protein expression was detected with Western blot. The cell proliferation capability was measured with methyl thiazolyl tetrazolium (MTT). The cell cycle was analyzed by flow cytometry (FCM). The capability of cell migration was determined by Transwell method. Also the DJ-1expression plasmid with SBP and CBP tags was constructed, and stably transfected into DJ-1siRNA SK-MES-1, SK-MES-1, DJ-1siRNA HTB-182and HTB-182cells with liposome to identify the DJ-1interacting proteins.Results Compared to control-siRNA and blank-control groups, the results showed that the protein expression of DJ-1gene was down-regulated, the capability of cell proliferation was significantly inhibited, the cell cycle was arrested with the increased number of G1-and G2-phase cells and the reduced number of S-phase cells, and the capability of cell migration was significantly decreased (P<0.05) in the DJ-1siRNA-infected SK-MES-1and HTB-182cells. Moreover, stably expressed PNTAPB-DJ-1plasmid cell lines were constructed successfully for identification of DJ-1interacting proteins.Conclusion DJ-1gene promotes cell proliferation and cell migration capability in vitro in lung squamous carcinoma SK-MES-1and HTB-182cells. Also, stably expressed PNTAPB-DJ-1expression plasmid cell lines was constructed successfully, and three potential DJ-1interacting proteins were identified, including keratin1, keratin10, and P47Px.