# A mechanical view on metastasis and the role of tumour cell viscosity

**Source**: https://bsse.ethz.ch/news-and-events/d-bsse-news/2026/01/a-mechanical-view-on-metastasis-and-the-role-of-tumour-cell-viscosity.html
**Parent**: https://bsse.ethz.ch/news-and-events.html

Millions are diagnosed with cancer each year. In advanced tumours, cells spread via blood or lymph, facing mechanical challenges. A multidisciplinary team, including Daniel Müller’s Biophysics group, studied how the mechanics of circulating tumour cells affect metastasis. Their findings, published in Nature Materials, offer key insights into how metastases form.

Tumour cells leaving the original tissue and settling in distant organs of the body is referred to as metastasis of the primary tumour. Since in most cases it is not the primary tumour but metastases that cause cancer-related deaths, a fundamental understanding of how tumour cells overcome the body’s own barriers is crucial for successful cancer treatment. To form metastases, tumour cells must detach from the primary tumour, enter the bloodstream, travel through the circulatory system, become lodged in small blood vessels, exit them (extravasation), and finally colonise a new tissue. Although it is known that mechanical properties influence the success of metastasis, the fundamental mechanisms behind this are still unclear.

**Physical constraints on circulating tumour cells**

A collaborative research team of biology and metastasis experts and physicists involving the the Centre de Recherche en Biomédecine de Strasbourg (INSERM/Unistra, CRBS), the Max-Planck-Zentrum für Physik und Medizin (MPZPM), and the ETH-Departement of Biosystems Science and Engineering, has analysed the physical constraints that tumour cells face on their way to metastasis, and investigated how their mechanical behaviour affects their progression through the metastatic process. The scientists consider circulating tumour cells as objects with a certain size and deformability. These are exposed to forces as they move through the circulatory system and invade surrounding tissues.

**Squishy or springy: Properties of tumour cells**

The team focuses on the ability of cells to respond to these forces elastically or viscously. Cells are viscoelastic, which means they are both squishy and springy. When you push on them slowly, they behave like a liquid and gradually flow or deform (viscous behaviour). When you push on them quickly, they behave like a spring and snap back to their original shape once the force is removed (elastic behaviour).

> “Our results suggest tumour cells benefit from switching between viscosity states during metastasis, supporting the idea that mechanically adaptable cells are the most dangerous and most capable of forming metastases.”
>
> Valentin Gensbittel, first author of this study and postdoctoral researcher in the Biophysics group at D-BSSE

The scientists combine biological models with tailored biophysical tools to probe cellular behaviour. For the first time, this combination enabled them to study directly how elastic and viscous behaviours influence tumour cell circulation, arrest, and exit from blood vessels during metastasis. They relied on two kinds of models: hydrogel beads, that mimic the elastic behaviour of cells, and engineered cells modified to exhibit specific viscoelastic profiles.

Read on >> find full-length [external page news post on the MPZPM website](https://mpzpm.mpg.de/news/news-details/a-mechanical-view-on-metastasis-and-the-role-of-tumor-cell-viscosity).

This news post is based on a [external page media release issued by Max Planck-Zentrum für Physik und Medizin](https://mpzpm.mpg.de/news/news-details/a-mechanical-view-on-metastasis-and-the-role-of-tumor-cell-viscosity) (23 January 2026).

## Find original Publication in *Nature Materials*:

Gensbittel, V., Yesilata, Z., Bochler, L. et al. (2026) [external page Cell viscosity influences haematogenous dissemination and metastatic extravasation of tumor cells.](https://rdcu.be/e1lxx) *Nature Materials*, DOI: https://doi.org/10.1038/s41563-025-02462-w\
  \
 Learn about research in the [Biophysics group led by Daniel Müller](https://ethz.ch/content/specialinterest/bsse/biophysics/en).