The Leading Edge

When there’s resistance to progress, sometimes you have to push a little harder. New research explores how cells drive their edges forward as they migrate, extending protrusions called lamellipodia. These are powered by branching networks of actin fibres, built by a protein machine called the Arp2/3 complex. Researchers watched cells under different physical conditions to ask what makes this actin network denser at the leading edge. They saw cells form strong, dense networks when they could grip a structured surface. Additionally, a similar effect appeared when the surrounding liquid was made more viscous, suggesting that mechanical resistance itself can boost the actin machinery that helps cells move (pictured, cells at 0 and 60 minutes in normal liquid, top, and extra-viscous liquid, bottom, with Arp2/3 in pink and cell outlines tracked over time, right). This advances our understanding of cell movement, fundamental to wound repair, immunity, and cancer.

Written by Anthony Lewis

Anthony Lewis

Writer

Ant was the web editor in the early days of BPoD, and has since worked with the UK’s top science organisations as a writer and multimedia producer. He now splits his time between freelance work and managing multimedia at The Lancet.

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• Image from work by Mitchell T. Butler and colleagues
• UNC Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in bioRxiv, March 2026 (not peer reviewed)