Research On The Elasticity Of Breast Cancer Cells By Atomic Force Microscopy

Breast cancer is one of the major diseases that threaten women’s health and life.With the development of society, the incidence of breast cancer in women also showedan increasing trend. The changes in cystoskeleton structure, surface morphology andmechanical properties of carcinomatous cells is collected with complex physiologicalprocesses that occur in diseased cells. Simultaneously, the compositions of extracellularmatrix in cancer tissues, such as collagen and fibronectin, will also have some change.Clarify the relationship between the change of cell stiffness and tumor tissue matrixcomponents is helpful to explain tumor progression.Atomic Force Microscope (AFM) can measure the biomechanical properties andscan the surface topography of living cells at liquid environment. As the performanceoptimization and upgrading, AFM is becoming more and more widely applied inbiomedical research, and has great value in biomechanical research, such as cellelasticity measurement.The major contents and results are as follows:⑴It was found from AFM indentation experiments that the elasticity of breast cancercells and normal breast cells from the same patient have significant difference, andthe Yong’s modulus of breast cancer cells from different patients also were different.⑵The effects of collagen I and fibronectin on breast cancer cells adhesion andspreading was analyzed. The experimental result displayed that Col I promoted theadhesion and spreading of both MCF-7and MDA-MB231.⑶F-actin of MCF-7and MDA-MB231, stained by FITC-phalloidin. It was showedthat the two cells lines, especially MDA-MB231had a more pronounced andwell-aligned network of actin fibers when cultured on Col I and these actin filamentswere parallel in the cytoplasm.⑷MTT assay showed that FN significantly promoted proliferation of MDA-MB231cells compared to Col I. Similarly, FN induced MCF-7cell proliferation as well. Cellwound healing assay showed that FN-coating had the trend to promote the migrationof both cell lines, although it was not statistically significant. Both syndecan-1andsyndecan-4antibodies suppressed FN-stimulated tumor cell proliferation. Moreover,the two antibodies slightly inhibited the migration of MCF-7and MDA-MB231.⑸Then the elasticity of single breast cancer cell was measured by AFM. It has been shown that MDA-MB231was more stiffer when cultured on FN than on Col I,while MCF-7is more stiffer on Col I.⑹Colchicine and cytochalasin D broken cystoskeleton components of breast cancercell, and then influenced cellular elasticity.