Twist1 correlates with poor differentiation and progression in gastric adenocarcinoma via elevation of FGFR2 expression

Figure 4 Fibroblast growth factor receptor 2 is required in Twist1-induced invasion and epithelial-mesenchymal transition rather than proliferation. A: Fibroblast growth factor receptor (FGFR) 2 knockdown did not block Twist1-induced proliferation in MKN28 cells. Proliferative ability was assessed by MTT assay in MKN28 48 h after transfection with Twist1 vector and FGFR2 siRNA. Twist1 overexpression promoted proliferation, and FGFR2 knockdown had little influence on that. Data are displayed as mean ± SE from three independent experiments. ^aP < 0.05 Twist1 overexpression vs control group. N.S.=not significant; B-E: Representative Transwell figures of MKN28 without transfection (B), and MKN28 transfected with control pFLAG-CMV2 vector (C), pFLAG-Twist1 vector (D), and pFLAG-Twist1 + siFGFR2 (E); F: Invasive cell number was counted and analyzed by Student’s t test. Invasive ability was evaluated by Transwell assay 48 h after transfection of Twist1 vector and FGFR2 siRNA. The invasive ability was markedly elevated by Twist1 overexpression and this tendency decreased significantly when FGFR2 was knocked down by siRNA, indicating that FGFR2 played an essential part in Twist1-induced invasion in MKN28 cells. Data were acquired from three independent experiments and displayed as mean ± SE; ^aP < 0.05 Twist1 overexpression vs control; ^cP < 0.05 Twist1 + siFGFR2 vs Twist1 overexpression; G: FGFR2 was partly required in Twist1-induced EMT. Twist1 overexpression significantly promoted E-cadherin decrease, and N-cadherin and Snail-2 increase, demonstrating that Twist1 promoted EMT in MKN28 cells. When FGFR2 was knocked down and Twist1 was overexpressed, the change in E-cadherin and N-cadherin was impaired, whereas there was little change in Snail2, indicating that FGFR2 played an essential role in Twist1-induced EMT. (H) Signals from (G) were quantified by Image J software. Data were from 5 independent experiments, analyzed by Student-t test and displayed by ± SE. ^eP < 0.05 vs corresponding control group respectively; ^fP < 0.01 vs control group regarding to FGFR2 expression.