  Cell migration and mechanics are tightly regulated by the integrated
activities of the various cytoskeletal networks. In cancer cells, cytoskeletal
modulations have been implicated in the loss of tissue integrity, and
acquisition of an invasive phenotype. In epithelial cancers, for example,
increased expression of the cytoskeletal filament protein vimentin correlates
with metastatic potential. Nonetheless, the exact mechanism whereby vimentin
affects cell motility remains poorly understood. In this study, we measured the
effects of vimentin expression on the mechano-elastic and migratory properties
of the highly invasive breast carcinoma cell line MDA231. We demonstrate here
that vimentin stiffens cells and enhances cell migration in dense cultures, but
exerts little or no effect on the migration of sparsely plated cells. These
results suggest that cell-cell interactions play a key role in regulating cell
migration, and coordinating cell movement in dense cultures. Our findings pave
the way towards understanding the relationship between cell migration and
mechanics, in a biologically relevant context.
