Fig. 4

PS effectively prevents LLC cells from binding to DPP IV and colonizing and metastasizing to the lungs. a Suspended LLC cells treated with DMSO (control) or 100 μM PS were subjected to the binding of DPP IV ^(31–767) that was derived from full-length DPP IV and retained the polyFN-binding ability. The cells were then subjected to IF staining using 6A3 mAb and phycoerythrin-conjugated goat anti-mouse antibody. The averaged red fluorescence intensities (absolute DPP IV-binding levels) of representative cell images as circled with white dashed lines (left two panels) were quantified in the right panel. b Representative images (left three panels) and quantifications (right panel) of mouse lung-colonized suspended LLC cells that were treated with DMSO, 75 μM or 100 μM PS. Circled dots with dashed lines represent the colonized LLC cells labeled with CFSE dye as illustrated with ImageJ software. c Lung weight/body weight (LW:BW) of the lungs in mice intravenously receiving LLC cells treated with DMSO (control) or two concentrations of PS upon mouse sacrifices. Mouse lungs (d) were taken and tumor nodule numbers (e) on lung surfaces from mice as described in (c) were counted upon mouse sacrifices. Black arrow heads depict tumor nodules in the lungs