Exploiting differential effects of actomyosin contractility to control cell sorting among breast cancer cells

Abstract

To gain a greater understanding of the factors that drive spatial organization in multicellular aggregates of cancer cells, we investigate the segregation patterns of 6 breast cell lines (MDA-MB-231, MDA-MB-468, MDA-MB-436, MDA-MB-157, ZR-75-1, and MCF-10A) of varying degree of mesenchymal character during formation of mixed aggregates. We consider cell sorting in the context of available adhesion proteins and cellular contractility, biophysical properties that are typically considered in models of cell sorting. We characterize the mechanisms of spheroid formation as being primarily cadherin- or integrin-driven. The primary compaction mediator for a given cell type plays an important role in compaction speed, which in turn is the major factor dictating preference for interior or exterior position within mixed aggregates. In particular, cadherin-deficient, invasion-competent cells tend to position towards the outside of aggregates, facilitating access to extracellular matrix. We show that reducing actomyosin contractility has a differential effect on spheroid formation depending on the compaction mechanism. Inhibition of contractility has a significant stabilizing effect on cell-cell adhesions in integrin-driven aggregation and a mildly destabilizing effect in cadherin-based aggregation. This differential response is exploited as a spheroid formation method and as a method through which to statically control aggregate organization and dynamically rearrange cells in pre-formed aggregates. Sequestration of invasive cells in the interior of spheroids provides a physical barrier that reduces invasion in three-dimensional culture, revealing a potential strategy for containment of invasive cell types. [Media: see text] [Media: see text] [Media: see text]

Fiber Diameter and Architecture Direct Three-Dimensional Assembly of Pericytes into Spheroids

“…Actin-myosin contractility can alter spheroid behavior and compaction in various cell types such as human mesenchymal stem cells, breast and ovarian cancer cell lines. 43,60,61 We confirm a destabilizing effect on pericyte spheroids with ROCK inhibition and show that assembly of spheroids was prevented by inhibiting actin-myosin contractility.…”

“…Actin-myosin contractility can alter spheroid behavior and compaction in various cell types such as human mesenchymal stem cells, breast and ovarian cancer cell lines. 43,60,61 We confirm a destabilizing effect on pericyte spheroids with ROCK inhibition and show that assembly of spheroids was prevented by inhibiting actin-myosin contractility. Interestingly, while control cells form the spheroids and elongated structures with 7 days, pericytes cultured for a week under ROCK-inhibition failed to assemble into spheroids but immediately did so within 24 hours upon removal of the ROCK inhibitor.…”

Surface activity of cancer cells: The fusion of two cell aggregates

“…(1) solid stress accumulated within the aggregate core region (Kalli and Stylianopoulos, 2018), (2) tissue surface tension (Devanny et al, 2021), and (3) viscoelasticity caused by collective cell migration (CCM) (Pajic-Lijakovic and Milivojevic, 2019a;2022). In this review, we have discussed the influence of these factors on cell rearrangement studied in the model systems such as the fusion of two cell aggregates by emphasizing the difference between epithelial and cancer cells.…”

“…Beside multicellular systems, the surface tension represents a characteristic of various soft matter systems such as: liquids and amorphous solids (Mondal et al, 2015). While epithelial cells within the aggregate establish strong Ecadherin mediated adherens junctions (AJs), cancer cells frequently establish weak cell-cell adhesion contacts and β 1 integrin mediated focal adhesions (FAs) between cells and ECM which are already present within the cell aggregates (Kenny et al, 2007;Devanny et al, 2021). Consequently, the resulted surface tension of epithelial aggregates is much higher than the one of the cancer aggregates.…”

“…Cell contractility significantly influences the surface tension. Epithelial cell contractions enhance the strength of AJs and cause an increase in tissue surface tension (Lin et al, 2006;Devanny et al, 2021). Migrating clusters of epithelial cells have higher tissue surface tension in comparison with resting (non-contractile) epithelial cells.…”