title: Atomic force microscope-based single cell force spectroscopy of breast cancer cell lines: an approach for evaluating cellular invasion.
abstract: The adhesiveness of cancerous cells to their neighboring cells significantly contributes to tumor progression and metastasis. The single-cell force spectroscopy (SCFS) approach was implemented to survey the cell-cell adhesion force between cancerous cells in three cancerous breast cell lines (MCF-7, T47D, and MDA-MB-231). The gene expression levels of two dominant cell adhesion markers (E-cadherin and N-cadherin) were quantified by real-time PCR. Additionally, the local stiffness of the cell bodies was measured by atomic force microscopy (AFM), and the actin cytoskeletal organization was examined by confocal microscopy. Results indicated that the adhesion force between cells was conversely correlated with their invasion potential. The highest adhesion force was observed in the MCF-7 cells. A reduction in cell-cell adhesion, which is required for the detachment of cells from the main tumor during metastasis, is partly due to the loss of E-cadherin expression and the enhanced expression of N-cadherins. The reduced adhesion was accompanied by the softening of cells, as described by the rearrangement of actin filaments through confocal microscopy observations. The softening of the cell body and the reduced cellular adhesiveness are two adaptive mechanisms through which malignant cells achieve the increased deformability, motility, and strong metastasis potential necessary for passage through endothelial junctions and positioning in host tissue. This study presented application of SCFS to survey cell phenotype transformation during cancer progression. The results can be implemented as a platform for further investigations that target the manipulation of cellular adhesiveness and stiffness as a therapeutic choice.
authors.affiliation: Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
authors.forename: Ramin
authors.initials: R
authors.lastname: Omidvar
authors.affiliation: Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran. Electronic address: tafazoli@aut.ac.ir.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Tafazzoli-Shadpour
authors.affiliation: National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran.
authors.forename: Mohammad Ali
authors.initials: MA
authors.lastname: Shokrgozar
authors.affiliation: Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
authors.forename: Mostafa
authors.initials: M
authors.lastname: Rostami
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism; D001943:Breast Neoplasms / Q000473:pathology*; D015820:Cadherins / Q000235:genetics; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002465:Cell Movement; D055119:Elastic Modulus; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D018625:Microscopy, Atomic Force; D009361:Neoplasm Invasiveness; D060888:Real-Time Polymerase Chain Reaction; D059010:Single-Cell Analysis
chemical_list: D015820:Cadherins
keywords: Atomic force microscopy; Breast cancer; Cellular adhesion force; Cellular invasion; Single cell force spectroscopy