Fig 3.

Effect of ectopic expression of Twist1 and Twist2 by pcDNA3.1 in the HCC cell lines HepG2 and PLC cells. (A) We determined that the expression of the epithelial marker E-cadherin was down-regulated after Twist1 transfectant, which was detected by Western blot analysis. For the Twist2 transfectant, E-cadherin showed no significant differences between the transfect and control groups for HepG2 and PLC cells. (B) Based on zymographic assays, the activities of MMP2 and MMP9 in HepG2 and PLC cells were significantly higher in the Twist1 up-regulation group than with the control group, but Twist2 did not present the same changes after transfection. (C) To investigate further the effects of Twist1 and Twist2 activation on cell invasion, we used transwell invasion assay to analyse the different influences between Twist1 and Twist2. We studied the invasion ability of HepG2 and PLC cells after performing Twist1 and Twist2 ectopic transfection. The quantitative analysis suggests a significant difference between the Twist1 transfection groups and the control group (P < 0.05). Twist2, however, showed no significant result in HepG2 and PLC cells (P > 0.05).