Fig. 3. Effects of CXCR4 downregulation on the proliferation, migration and invasive ability in H1299 cell lines. A. CXCR4 was knocked down via siRNA transfection. The mRNA levels were measured with qRT-PCR (n=3, *p<0.05, compared with the control group or siRNA negative control group; NS, not significant). B. The CXCR4 protein levels were significantly decreased in the group transfected with siRNA against CXCR4 compared with that in the negative control group (n=3, *p<0.05, compared with the siRNA negative control group). C. The migration ability of H1299 cells in the presence or absence of siRNA CXCR4 was evaluated via the wound-healing assay. Representative images were recorded at 0, 24 and 48 h post-wound time points. D. Quantification of healing distance (n=3, *p<0.05, compared with the control group or siRNA negative control group). E. Matrigel assay of H1299 cells transfected with siRNA against CXCR4 or control siRNA. Migratory cells were counted in 10 non-overlapping areas and quantified using a bar graph (n=3, *p<0.05, compared with the control group or siRNA negative control group). F. H1299 cell proliferation was measured using a CCK-8 kit. The OD values were measured at 24, 48 and 72 h in the control group and CXCR4-knockdown group (n=5, *p<0.05, compared with the siRNA negative control group).