Single-Cell Probe Force Studies to Identify Sox2 Overexpression-Promoted Cell Adhesion in MCF7 Breast Cancer Cells

Abstract

The replacement of the cantilever tip by a living cell in Atomic Force Microscopy (AFM) experiments permits the direct quantification of cell–substrate and cell–cell adhesion forces. This single-cell probe force measurement technique, when complemented by microscopy, allows controlled manipulation of the cell with defined location at the area of interest. In this work, a setup based on two glass half-slides, a non-fouling one with bacterial S-layer protein SbpA from L. sphaericus CMM 2177 and the second with a fibronectin layer, has been employed to measure the adhesion of MCF7 breast cancer cells to fibronectin films (using SbpA as control) and to other cells (symmetric vs. asymmetric systems). The measurements aimed to characterize and compare the adhesion capacities of parental cells and cells overexpressing the embryonic transcription factor Sox2, which have a higher capacity for invasion and are more resistant to endocrine therapy in vivo. Together with the use of fluorescence techniques (epifluorescence, Total Internal Fluorescence Microscopy (TIRF)), the visualization of vinculin and actin distribution in cells in contact with fibronectin surfaces is enabled, facilitating the monitoring and quantification of the formation of adhesion complexes. These findings demonstrate the strength of this combined approach to assess and compare the adhesion properties of cell lines and to illustrate the heterogeneity of adhesive strength found in breast cancer cells.

miR-301 regulates the SIRT1/SOX2 pathway via CPEB1 in the breast cancer progression

“…Notably, it has been suggested in hepatocellular carcinoma cancer that SIRT1 mediates the cell self-renewal through transcriptional regulating SOX2, 12 , 13 and SOX2 overexpression promoted cell adhesion in MCF-7 breast cancer cells. 34 Our results delineated that SIRT1 could modulate expression of SOX2, which was also upregulated in cells in the presence of CPEB1 knockdown, indicating that CPEB1 suppressed the expression of both SIRT1 and SOX2 and thus restrained breast cancer progression. Thus, CPEB1 may be a significant tumor suppressor in breast cancer by post-transcriptional regulating the SIRT1/SOX2 signaling pathway.…”

The SOX2 Status of Disseminated Tumor Cells in Breast Cancer Patients Treated With Neoadjuvant Chemotherapy

“…A high expression of SOX2 has been indeed demonstrated in BC cell lines known for their crossresistance to taxanes, anthracyclines and cisplatin (30). Furthermore, SOX2 expression has been linked to tamoxifen resistance in BC (44) and was shown to significantly affect adhesion properties of BC cells (45). SOX2 was also recently shown to mediate proliferation and dissemination in lung cancer cells resistant to tyrosine kinase inhibitors (46).…”

Laser-Assisted Direct Grafting of Poly(ethyleneimine) on Poly(methyl methacrylate)

“…During retraction after maximum extension, the force decreases and reaches negative values due to adhesion. After the force reaches the minimum (maximum adhesion force) [ 33 , 34 , 35 ] ( Figure 6 (a)–(c)), the complete detachment of the tip from the surface occurs until the force reaches zero. The rupture length is defined as the length from the force of zero, which represents the starting point for detachment, to the complete detachment of the tip ( Figure 6 (a’)–(c’)).…”