Fig. 1

Extracellular ATP induces detachment and recolonization of cancer cells. A549 or H1299 cells growing in cell culture plates were incubated with or without ATP for various times. After incubation, floating cells were collected, and the live floating cells were counted. The total floating cells were then re-plated for clone formation. a Direct count of viable floating cells under different ATP concentration. b A clonogenic assay using floating cells isolated from the same volume of cell culture media. c Fence assay. Cells were seeded inside a ring-shaped plastic device. After cell attachment, the ring was removed, and the cells were incubated with or without ATP for 2 weeks for examination of cell detachment and recolonization at other places in the wells. Experiments were performed in triplicate and data are presented as the mean ± standard deviation. *P < 0.05, **P < 0.01 and ***P < 0.001