Abstract: Objective To explore the influences of decorin(DCN)gene down-regulating on biological behavior in human lung adenocarcinoma A549 cell line.Methods Chemically synthesis in vitro targeting DCN-siRNA was transfected into human lung adenocarcinoma A549 cells by LipofectamineTM 2000.The gene expression of DCN was detected using Real-Time PCR;The protein expression of DCN was investigated using Western blot;Checkout DCN-siRNA effects on lung adenocarcinoma cancer cell proliferation was detected by CCK-8;The migration and invasion ability were determined by Transwell assay.Results DCN-siRNA was successfully transfected into human lung adenocarcinoma A549 cells.Real-Time PCR results showed that DCN mRNA expression level significantly decreased,compared with untransfected group,negative control group.Western blot results showed that DCN-siRNA transfection inhibited DCN protein expression level;CCK-8 results showed that the proliferation was enhanced in the DCN-siRNA group as compared with untransfected group,as well as the negative control group and empty vector group.Transwell assay results showed the invasion of A549 cells in DCN-siRNA group was significantly enhanced as compared with untransfected group[(22.6±1.14)vs.(5.2±0.84)].Wound-Healing assay results revealed that the cell repairing rate was markedly increased in DCN-siRNA group.A549 cells were close to complete repair after 48 hours.Apoptosis was not significant in DCN-siRNA group as compared with untransfected group(P=0.214).Conclusion Down-regulation the expression of DCN gene by DCN-siRNA may enhance the ability of invasion,migration and proliferation of A549 cells without affecting apoptosis,which provides a new evidence of function for advancing research of lung cancer.

Key words: Decorin gene, siRNA in terference, Proliferation, Migration, Invasion