Characterization of Breast Cancer Aggressiveness by Cell Mechanics

In healthy tissues, cells are in mechanical homeostasis. During cancer progression, this equilibrium is disrupted. Cancer cells alter their mechanical phenotype to a softer and more fluid-like one than that of healthy cells. This is connected to cytoskeletal remodeling, changed adhesion properties, faster cell proliferation and increased cell motility. In this work, we investigated the mechanical properties of breast cancer cells representative of different breast cancer subtypes, using MCF-7, tamoxifen-resistant MCF-7, MCF10A and MDA-MB-231 cells. We derived viscoelastic properties from atomic force microscopy force spectroscopy measurements and showed that the mechanical properties of the cells are associated with cancer cell malignancy. MCF10A are the stiffest and least fluid-like cells, while tamoxifen-resistant MCF-7 cells are the softest ones. MCF-7 and MDA-MB-231 show an intermediate mechanical phenotype. Confocal fluorescence microscopy on cytoskeletal elements shows differences in actin network organization, as well as changes in focal adhesion localization. These findings provide further evidence of distinct changes in the mechanical properties of cancer cells compared to healthy cells and add to the present understanding of the complex alterations involved in tumorigenesis.

Automated summary

In healthy tissues, cells are mechanically stable. However, during cancer progression, cancer cells undergo changes in their mechanical properties, becoming softer and more fluid-like. This is associated with cytoskeletal remodeling, altered adhesion properties, increased cell proliferation, and enhanced cell motility. In our study, we examined the mechanical properties of different breast cancer cells using atomic force microscopy force spectroscopy. Our results revealed that the mechanical properties of the cells are linked to their malignancy, with tamoxifen-resistant MCF-7 cells being the softest and MCF10A cells being the stiffest. Confocal fluorescence microscopy further demonstrated differences in actin network organization and focal adhesion localization. These findings contribute to our understanding of the complex alterations involved in cancer development.