Fig. 1

The effect of insulin on invasion and migration in MDA-MB-231 and MCF-7. a and b MDA-MB-231 cells and c and d MCF-7 cells were scratched by a micropipette tip and then incubated with or without insulin for 24 h (both n = 4). Cells were photographed and the distance was measured under microscope. e and f MDA-MB-231 cells and g and h MCF-7 cells were seeded separately into 8 μm-pole transwell chamber at 80~90% confluence. After starving for 12 h, monolayer cells were treated with or without insulin for 48 h, and then the filter was washed, stained and photographed under a microscope (both n = 4). *P < 0.05, ** P < 0.01 vs. control