GPR39 promotes G1/S transition and enhances cell motility. (A) DNA content between GPR39-expressing cells and control Vec-30 cell were compared by Flow-cytometry. Untreated, cells were cultured in DMEM medium with 10% FBS; Withdraw serum, cells were cultured in DMEM medium without serum for 3 days; Add serum, cells were cultured again in DMEM medium with 10% FBS for 8 hr. (B) Expression of p21, cyclin D1, CDK4, and CDK6 were compared between GPR39-expressing cells (c4) and control Vec-30 cells by Western blot analyses. GAPDH was used as loading control. (C) The effect of GPR39 on cell migration was determined by wound-healing assay. During a period of 16 hr, the spreading speed of GPR39-expressing cells along the wound edge was faster than that in control Vec-30 cells. (D) Representative images showed the GPR39-expressing cells and Vec-30 cells that invaded through the matrigel. Number of invaded tumor cells was quantified in the right panel. Columns, mean of triplicate experiments; **P < 0.01.