SHP2 depletion or catalytic deficiency mutant inhibits migration and invasion of oral cancer cells. (A) Cells transfected with SHP2 si-RNA (si-SHP2#1 or si-SHP2#2) or Negative control (si-NC) were seeded onto the transwell chamber coated with or without matrigel as described in Materials and Methods. Cells adhering to the lower chamber after the migration or invasive process were stained with crystal violet solution, and images were taken under bright-field microscopy at 40×. An obvious decrease in migration (Upper panel) and invasion (middle panel) ability was noted in HSC3 cells transfected with SHP2 si-RNA (si-SHP2#1 or si-SHP2#2) compared to Negative control (si-NC). Western blot shows the expression of SHP2 in HSC3 cells transfected with SHP2 si-RNA or Negative control (Lower panel). (B) Effect of SHP2 knockdown on invasion of HSC3-Inv4 and HSC3-Inv8 cells (Upper panel, left and right, respevtively). The quantitative data are expressed as mean ± SD from three independent experiments; *, P < 0.05 (Middle panel). Western blot shows the expression level of SHP2 in HSC3-Inv4 and HSC3-Inv8 cells transfected with SHP2 si-RNA or Negative control (Lower panel, left and right, respectively). (C) A dramatic decrease in migration (Left panel) and invasion ability (Middle panel) was observed in HSC3 cells transfected with SHP2 C459S mutant (SHP2C/S) compared to the SHP2 wild type (SHP2WT). Evaluation on SHP2 activity of the cells transfected with indicated constructs. Experiments were done in triplicate at least, and values are indicated as mean ± SD. *, P < 0.05 (Right upper panel). Western blot shows the expression level of transfected flag-SHP2 proteins (Right lower panel).