Nucleus Signals Cells to Move When Squeezed

Photo: Alexis Lomakin, PhD, Copyright: St. Anna Children’s Cancer Research Institute.

Scientists understood in 2015 that putting physical pressure on cells – by crowding – causes stationary cells to start moving. We now know it is the cell nucleus, which triggers this “evasion reflex,” and it is activated once cell compression exceeds the size of the nucleus.

Published in the journal Science, this finding could help to predict treatment response and metastatic spreading of tumors.

“Even when we are standing still, the cells in our bodies are going places,” said study coauthor Ryan J. Petrie, PhD, an assistant professor of biology in Drexel University’s College of Arts and Sciences. “It is now clear that an individual cell can change how it moves in response to the material surrounding it.”

A main research focus in Petrie’s Lab is the contractility of cells – or how they move through 3-dimensional (3D) environments, e.g. the human body.

“Classically, people have used 2-dimensional glass slides to study motility where it is relatively easy to image the cellular and molecular mechanisms driving cell movement. But while these observations are valuable, they do not always provide an understanding of how cells move through the 3D tissues in the human body,” explains Petrie.

Alexis Lomakin, a cell biologist at the St. Anna Children’s Cancer Research Institute in Vienna and a lead author of the study, similarly wanted to understand how cells move through tissues to keep us healthy, so both teams came together to better understand how cells respond to the different types of 3D tissue structures that occur in the human body.

The researchers’ discovered that the nucleus can be squeezed and deformed when the cell is moving through 3D tissues. When the nucleus changes shape in this way it generates a signal to activate the contractile machinery that helps power the cells through tight spaces. This new finding is counter to traditional view that the nucleus primarily serves as an inert storehouse for the cell’s genetic material, the DNA.

“Finding the nucleus can detect when the cell is in a confined space to trigger cell motility is like discovering another human sensory system, one that operates within each cell,” explains Petrie. “Its importance on the cellular level is akin to the five basic senses humans rely on: touch, sight, hearing, smell and taste.”

This discovery has the potential to lead to new methods and drugs to inhibit and prevent tumor cells from moving. In the future, these approaches could slow or even stop the spread of metastatic disease.

Media interested in speaking with Petrie can contact Emily Storz, or 215-895-2705.

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