Figure 2

PL inhibited in vitro invasion and motility of SW480 cells and the activity of MMP-9. A, The histogram shows the mean number of invasive cells for a 20× field of view. Counts were performed on three inserts and five fields of view per insert. Cells were loaded onto Matrigel-coated upper chambers of Transwell plates and treated with the indicated concentrations of PL; filtrated cells were stained. The error bars represent the SD of the mean number of invasive cells per field of view for all fields. ***, P < 0.001 versus control. B, Cells were loaded onto gelatin-coated upper chambers, and filtrated cells were stained. The histogram shows the mean number of invasive cells for a 20× field of view. Counts were performed on three inserts and five fields of view per insert. The error bars represent the SD of the mean number of invasive cells per field of view for all fields. ***, P < 0.001 versus control. C, Conditioned media was prepared from SW480 and HT1080 cells and electrophoresed in a gel containing gelatin. The gels were incubated for 24 h with the indicated concentrations of PL. The gel shown is representative of three independent experiments with similar results. D, The densities of bands of MMP-2 and MMP-9 were quantified by imaging densitometry. MMP-2 and MMP-9 activity of the control was set at 100%; the activities of PL-treated samples are represented as percentages of the control. *, P < 0.05 versus control; ***, P < 0.001 versus control.