The Migration of Cancer Cells in Gradually Varying Chemical Gradients and Mechanical Constraints

We report a novel approach to study cell migration under physical stresses by utilizing established growth factor chemotaxis. This was achieved by studying cell migration in response to epidermal growth factor (EGF) chemoattraction in a gradually tapered space, imposing mechanical stresses. The device consisted of two 5-mm-diameter chambers connected by ten 600 µm-long and 10 µm-high tapered microchannels. The taper region gradually changes the width of the channel. The channels tapered from 20 µm to 5 µm over a transition length of 50 µm at a distance of 250 µm from one of the chambers. The chemoattractant drove cell migration into the narrow confines of the tapered channels, while the mechanical gradient clearly altered the migration of cells. Cells traversing the channels from the wider to narrow-end and vice versa were observed using time-lapsed imaging. Our results indicated that the impact of physical stress on cell migration patterns may be cell type specific.