Mechanical control of mitotic progression in single animal cells

In animal tissue, most adherent cells round up against confinement to conduct mitosis. Impaired cell rounding is thought to perturb tissue development and homeostasis and contribute to progression of cancer. Due to the lack of suitable experimental tools, however, insight into the mechanical robustness of mitosis in animal cells remains limited. Here we introduce force-feedback-controlled ion beam-sculpted cantilevers to confine single cells and characterize their progression through mitosis. Our approach reveals critical yield forces that trigger cell cortex herniation, loss of F-actin homogeneity, dissipation of intracellular pressure, critical cell-height decrease, mitotic spindle defects, and resultant perturbation of mitotic progression.