Fig 2: Cell transfection with EPAC2 overexpression plasmid and Transwell invasion assays. (A) U251 cells were transfected with EPAC2 overexpression plasmid and Transwell invasion assays were performed. Counting of purple cells was performed using an Olympus CKX31 inverted light microscope. Original magnification, ×100. (B) Numbers of invasive U251 cells were quantified, and the results demonstrated that the invasive cell numbers were significantly reduced following transfection with EPAC2 overexpression plasmid. (C) U87 cells were transfected with EPAC2 overexpression plasmid and Transwell invasion assays were performed. Original magnification, ×100. (D) Numbers of invasive U87 cells were quantified, and the results demonstrated that the invasive cell numbers were significantly reduced following transfection with EPAC2 overexpression plasmid. ##P<0.01. EPAC2, exchange protein directly activated by cAMP 1.

Fig 3: EPAC2-MMP-2 pathway. Diagram showing the EPAC2-MMP-2 pathway which leads to reduced glioma invasiveness. EPAC2, exchange protein directly activated by cAMP 1; MMP-2, matrix metalloproteinase 2.

Fig 4: EPAC2 transfection. (A) U251 cells were transfected with EPAC2 overexpression plasmid to evaluate alterations in MMP-2 protein expression. (B) Statistical analysis following transfection of U251 cells with EPAC2 overexpression plasmid. (C) Statistical analysis suggested that following transfection of U251 cells with EPAC2 overexpression plasmid, the MMP-2 protein levels were significantly decreased. Relative protein expression levels of EPAC2 were elevated in EPAC2-plasmid transfected cells compared with the normal control and plasmid control groups in U251 cells. Bars represent relative protein levels. The mean values of the protein levels were normalized to 1.0. (D) U87 cells were transfected with EPAC2 overexpression plasmid to evaluate alterations in MMP-2 protein expression. (E) Statistical analysis following transfection of U87 cells with EPAC2 overexpression plasmid. (F) Statistical analysis revealed that, following transfection of U87 cell strain with EPAC2 overexpression plasmid, MMP-2 protein levels were significantly decreased. Relative protein expression levels of EPAC2 were elevated in EPAC2-plasmid transfected cells compared with the normal control and plasmid control groups in U87 cells. Bars represent relative protein levels. The mean values of the protein levels were normalized to 1.0. ##P<0.01. EPAC2, exchange protein directly activated by cAMP 1; MMP-2, matrix metalloproteinase 2.