Fig. 6.

Mapping intracellular mechanics shows that metastatic breast cancer cells are softer than nontumorigenic cells and reveals differences in the distribution of intracellular viscoelasticity. (A) Relaxation curves for nontumorigenic MCF-10A cells (black) and for metastatic MDA-MB-231 cells (red). (B) Average values of the shear modulus G₀, the storage modulus G′, and the loss modulus G″ in MCF-10A and MDA-MB-231 cells. (C) Maps showing the distribution of the shear modulus G₀ in MCF-10A and MDA-MB-231 cells. (D) Plots of the shear modulus as a function of the distance to the nucleus in MCF-10A and MDA-MB-231 cells (Left) and corresponding shear modulus gradients (Right). (E) Immunofluorescence images of microtubules and actin in MCF-10A and MDA-MB-231 cells. (Scale bar, 10 µm.) Data were obtained from n = 43 and 54 beads in MCF-10A cells and in MDA-MB-231 cells, respectively. Error bars represent SEs. P values are determined from Student’s t test for unpaired samples with respect to control cells (***P < 0.0001).