Local mechanical properties of bladder cancer cells measured by AFM as a signature of metastatic potential

The rheological properties of bladder cancer cells of different invasivities have been investigated using a microrheological technique well adapted in the range [1-300Hz] of interest to understand local changes in the cytoskeleton microstructure, in particular actin fibres. Drugs disrupting actin and acto-myosin functions were used to study the resistance of such cancer cells. Results on a variety of cell lines were fitted with a model revealing the importance of two parameters, the elastic shear plateau modulus G N 0 as well as the glassy transition frequency f T . These parameters are good markers for invasiveness, with the notable exception of the cell periphery, which is stiffer for less invasive cells, and could be of importance in cancer metastasis.