Figure 1.

LKB1 inhibits cell migration and invasion. (a-d) 2×10⁴ TC-1/shR-Ctrl or TC-1/shRLKB1 cells were seeded for migration assay using the Transwell Membrane Inserts (a and b) and for invasion assay with the pre-coated Matrigel Chambers (c and d). The cells were stained with 1% crystal violet and counted after 24 hours. (e) Wound-healing (scratch) assay was performed with TC-1/shR-Ctrl and TC-1/shR-LKB1 cells. Cells were photographed at 0 h and 24 h. (f) Quantification was carried out by measuring the migration distance compared with the controls. Data are mean ± S.D. from 3 independent experiments (*P < 0.01). (g-I) Ectopic expression of LKB1 inhibits cervical cancer cell migration and invasion. HeLa cells with inducible expression of LKB1 or GFP were established and designated as HeLa/pMEP4-GFP (control) or HeLa/pMEP4-LKB1. (g) Expression of LKB1 after induction with 100 μM zinc sulfate was confirmed by Western blot. (h and i) Migration and invasion assays were conducted as described above except that 100 μM zinc sulfate were added to the bottom well as a chemoattractant. The cells were stained with 1% crystal violet and counted after 24 hours. The data in panels b, d, h, and i represent mean ± S.D. of 3 independent experiments, each performed in duplicate (*P < 0.01).