Effects Of Knocking Down BFGF Expression On Characteristics Of Tumor Stem Cells In Lung Caner A549Cell Line

Objective:To investigate effects of knocking down bFGF expression by siRNA interference on OCT-4expression and tumor stem cell characteristics such as cell proliferation, clone formation, apoptosis and invadiness in lung adenocarcinoma A549cells.Methods:Pick out the optimal bFGF-siRNA which can most strongly inhibit bFGF expression. Then DDP selected A549cells were divided into three groups:PGCsiU6-bFGF-siRNA group (transfected with bFGF interference plasid),transfected with PGCsiU6-NC-siRNA(negative control group) and non-transfected group (blank control group). The bFGF and OCT-4mRNA levels of every group A549were detected by Real-Time PCR, the bFGF and OCT-4protein levels were detected by West Blot. Cell growth ability was determined by CCK-8colorimetry. Cell apoptosis was assessed by flow cytometry. Clone formation and Transwell experiment were used to evaluate the clone forming capacity and invading ability of cells.Results:Compared with blank control group, bFGF mRNA levels of negative control group, bFGF-siRNA-1, bFGF-siRNA-2and bFGF-siRNA-3group changed (1.028±0.215),(0.209±0.044, P<0.01),(0.609±0.158, K0.05) and (0.908±0.029) fold, respectively. OCT-4expression of negative control group,bFGF-siRNA-1, bFGF-siRNA-2and bFGF-siRNA-3group changed (1.022±0.121),(0.486±0.085, P<0.01),(0.796±0.138, P<0.05) and (0.879± 0.025) fold. In comparison with negative control group and blank control group, the PGCsiU6-bFGF-siRNA group cell proliferating capacity decreased (day2～4F<0.05, day5～7P<0.01). In PGCsiU6-bFGF-siRNA group, the clone formation ratio (12.25%±2.97%)was lower than blank control group (44.25%±3.31%, P<0.01) and negative control group(42.75%±4.50%, P<0.01). In PGCsiU6-bFGF-siRNA group, the ratio of cell apoptosis (26.67%±0.59%) was higher than blank control group (9.05%±1.20%, P<0.01) and negative control group (8.45%±1.18%, P<0.01); while the number of cell (10.83±1.72)passing through the member of Transwell chamber was smaller than blank control group (33.16±2.86, P<0.01) and negative control group (32.17±3.19, P<0.01).Conclusions:Targeted siRNA can inhibit bFGF expression. knocking-down bFGF expression can down-regulate OCT-4expression, affect tumor stem cell characteristics,decrease cell proliferation, clone formation, invasion capacity and induce cell apoptosis in the lung cancer cell line A549. Inhibiting bFGF expression via siRNA interference technology may be a effective selection for treating lung cancer, even aiming at lung cancer stem cells.