Disruption of nuclear-cytoskeletal connection impairs epithelial cell mechanosensing and collective migration.

The linker of nucleoskeleton and cytoskeleton (LINC) complex mediates physical communication between the cytoskeleton to the nucleus, thereby influencing nuclear positioning, transcriptional responses, and cell migration. Although prior studies have examined LINC's role in single-cell migration, its impact on collective migration of epithelial cells on surfaces of varying stiffness remains unclear. Here, we disrupted LINC function in MCF10A mammary epithelial cells using an inducible dominant-negative SUN1 construct (SUN1L) that sequesters nesprins. We found that MCF10A mammary epithelial cells with SUN1L expression were slower than wild-type controls on collagen-coated polyacrylamide hydrogels of 0.1-, 5-, and 50-kPa stiffness. Although migration speed of both control and SUN1L cells increased on stiffer substrates, the SUN1L cells displayed lower stiffness sensitivity, indicating impaired mechanosensing after LINC disruption. LINC disruption also altered cell and tissue-scale mechanics: SUN1L cells were smaller, softer, and formed denser epithelial sheets. Alongside these physical changes, LINC-disrupted cells showed stronger cell-matrix adhesions and reduced actomyosin contractility. Cytoskeletal perturbations further revealed that SUN1L cells are less reliant on actomyosin activity for sustained migration. These findings highlight how nuclear-cytoskeletal decoupling triggers multiscale physical changes-cell softening, crowding, and altered adhesion dynamics-that collectively impair mechanosensitive migration. Given LINC's implication in laminopathies and cancer, our results provide new insight into how its dysfunction may influence disease progression and collective cell behavior.