Cell shape noise strength regulates shape dynamics during EMT-associated cell spreading

Cellular shape is intimately linked to cell function and state, and transitions between cell states are tightly coupled to shape changes. Yet, shape has been largely overlooked in state transitions studies. Here, we combine morphometric analysis with theoretical modeling and molecular perturbations to interrogate cell shape dynamics during epithelial-to-mesenchymal transition (EMT). Using stochastic inference, we extract the morphogenetic landscape underlying EMT. We show that within this landscape, EMT-associated cell spreading reflects a transition between shape attractors. Strikingly, we observe a peak in cell shape noise strength concomitant with spreading, and show that higher shape noise accelerates transitions between shape attractors. Our morphometric analysis framework will be widely applicable to quantitative cell shape investigations in physiology and disease. Together, our results identify a key role for cellular stochasticity as a regulator of shape change rate, and highlight that shape dynamics yield rich phenotypic information that enhances our understanding of cellular states.