Figure 2. The influence of MTA1 expression on the malignant phenotypes of 1E8 cells.

(A) Treatment with MTA1 siRNA decreased MTA1 expression efficiently and enhanced E-cadherin expression. The protein levels were analyzed using Western blotting and were normalized to β-actin. The quantification of the band intensities is shown (top). An asterisk (*) or diamond (◊) indicates a statistically significant difference (p<0.05) in the MTA1 or E-cadherin levels, respectively, compared with the nontreated cells and the negative-control siRNA-transfected cells, n = 3. (B) The adhesive rate was quantified by the MTT assay, and a representative experiment is shown. The ability of the cells to adhere to a solid surface was significantly upregulated in the cells that had been treated with MTA1 siRNA. An asterisk (*) indicates a statistically significant difference (p<0.05) compared to the nontreated cells and negative-control siRNA-transfected cells. (C, D, and E) Using a Matrigel^TM-coated transwell system, the invasive ability of the cells treated MTA1 siRNA was tested. The quantification of the number of invasive cells from the bottom of the transwell inserts is shown in the lower panel. An asterisk (*) indicates a statistically significant difference (p<0.05) compared with the nontreated cells and negative-control siRNA-transfected cells. (F, G, and H) The changes in the cytoskeleton structure were detected by confocal microscopy: Red staining represents α-tubulin. Blue staining represents the nuclei. The ‘feet’ were shortened, and the polarization was weakened in cells treated with MTA1 siRNA. These changes indicate a reduced ability to move (400 fold). A representative result from three independent experiments is shown for all data.