Elasticity measurement of breast cancer cells by atomic force microscopy

Mechanical properties of living cells play an important role in understanding various cells’ function and state. Therefore cell biomechanics is expected to become a useful tool for cancer diagnosis. In this study, atomic force microscopy (AFM) using a square pyramid probe was performed to investigate cancerous (MCF-7) and benign (MCF-10A) human breast epithelial cells. The new QITM mode was used to acquire high-resolution topographic images and elasticity of living cells. Furthermore, individual force curves were recorded at maximum loads of 0.2, 0.5 and 1 nN, and the dependence of cell’s elasticity with loading force was discussed. It was showed that the cancerous cells exhibited smaller elasticity modulus in comparison to non-cancerous counterparts. The elasticity modulus increased as the loading force increased from 0.2 nN to 1 nN. This observation indicates that loading force affects the cell’s apparent elasticity and it is important to choose the appropriate force applied to cells in order to distinguish normal and cancer cells. The results reveal that the mechanical properties of living cells measured by atomic force microscopy may be a useful indicator of cell type and disease.

[1]  Igor Sokolov,et al.  Quantitative study of the elastic modulus of loosely attached cells in AFM indentation experiments. , 2013, Biophysical journal.

[2]  Igor Sokolov,et al.  Method for quantitative measurements of the elastic modulus of biological cells in AFM indentation experiments. , 2013, Methods.

[3]  Manfred Radmacher,et al.  Comparison of mechanical properties of normal and malignant thyroid cells. , 2012, Micron.

[4]  Małgorzata Lekka,et al.  Atomic force microscopy: A tip for diagnosing cancer. , 2012, Nature nanotechnology.

[5]  M. Rols,et al.  Imaging living cells surface and quantifying its properties at high resolution using AFM in QI™ mode. , 2013, Micron.

[6]  Rudolf Merkel,et al.  Keratins as the main component for the mechanical integrity of keratinocytes , 2013, Proceedings of the National Academy of Sciences.

[7]  S T Quek,et al.  Mechanical models for living cells--a review. , 2006, Journal of biomechanics.

[8]  J. Rao,et al.  Nanomechanical analysis of cells from cancer patients. , 2007, Nature nanotechnology.

[9]  C. Lim,et al.  AFM indentation study of breast cancer cells. , 2008, Biochemical and biophysical research communications.

[10]  A. Fuhrmann,et al.  AFM stiffness nanotomography of normal, metaplastic and dysplastic human esophageal cells , 2011, Physical biology.

[11]  Subra Suresh,et al.  Biomechanics and biophysics of cancer cells. , 2007, Acta biomaterialia.

[12]  Ueli Aebi,et al.  The nanomechanical signature of breast cancer. , 2012, Nature nanotechnology.

[13]  A. Jemal,et al.  Global Cancer Statistics , 2011 .

[14]  R. Mahaffy,et al.  Quantitative analysis of the viscoelastic properties of thin regions of fibroblasts using atomic force microscopy. , 2004, Biophysical journal.

[15]  M. Radmacher,et al.  Comparison of the viscoelastic properties of cells from different kidney cancer phenotypes measured with atomic force microscopy , 2013, Nanotechnology.