TGF-β regulates LARG and GEF-H1 during EMT to affect stiffening response to force and cell invasion.
Bottom Line: Recent studies implicate a role for cell mechanics in cancer progression.Previously, force application on integrins has been shown to initiate cytoskeletal rearrangements that result in increased cell stiffness and a stiffening response.Here we demonstrate that transforming growth factor β (TGF-β)-induced EMT results in decreased stiffness and loss of the normal stiffening response to force applied on integrins.
Affiliation: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.Show MeSH
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Mentions: Our results indicate that LARG and GEF-H1 are necessary mediators of stiffness (Figure 7B) and stiffness response (Figure 7C). To examine whether down-regulation of LARG and GEF-H1 was necessary and sufficient to restore post-EMT loss of stiffness and stiffness response phenotypes, we rescued GEF expression after EMT induction and performed mechanical and invasion assays. Post-EMT NMuMG cells were transfected with plasmids containing cDNA to encode GFP-tagged LARG and GEF-H1 to rescue the reduced expression (Figure 8A). Mechanical measurements were performed only on LARG- or GEF-H1–expressing cells, as identified by GFP expression. We found that restoring LARG or GEF-H1 expression rescued the 50% post-EMT reduction in cell stiffness to 70 and 80% of the GFP-control stiffness, respectively (Figure 8B). Similarly, restoring LARG or GEF-H1 expression rescues the 30% post-EMT reduction in stiffening response to 90% of the response observed in GFP-control cells (Figure 8C).
Affiliation: Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599.