Electrically Assessing the Effect of TGF-β1 on MDA-MB-231 Cells

We investigated the effect of transforming growth factor-beta1 (TGF-

β

1) on cell micromotion and wound healing migration of breast adenocarcinoma cells, MDA-MB- 231. Central to this work was the use of electric cell-substrate impedance sensing (ECIS), a cell-based biosensor that monitors motility and other morphology changes of cells adherent on small gold electrodes. To detect the alternation of cell micromotion in response to 10 ng/ml of TGF-

β

1 challenge, timeseries impedance fluctuations of cell-covered electrodes were monitored and the values of variance, power slope, and Hurst coefficient were calculated to verify the difference. These measures describe the motile and persistent behavior of these cells in culture. Furthermore, ECIS wounding assay was used to wound and monitor the healing process of TGF-

β

1 treated cell layers. Our data indicated that TGF-

β

1 treated MDA-MB- 231 cells, in comparison to control cells, demonstrated higher fluctuation amplitude and unreduced long-term correlation for about 20 hours long. In addition, the wound healing rate of MDA-MB-231 cells significantly increased after cells were treated with 10 ng/ml of TGF-

β

1 though the effect decreased along with time. The results suggest that treatment of MDAMB- 231 cells with TGF-

β

1 facilitates their scattering behavior.