COPENHAGEN, Denmark — It turns out our cells have a lot more in common with octopuses than many people might think. A new study is revealing how both good and bad cells move throughout the human body — using “tentacles” to change direction and invade nearby tissues. Importantly, scientists say taking these legs away could stop cancer’s ability to spread.
Researchers from the University of Copenhagen note that scientists already knew these tentacle-like arms worked like sensors on the surface of cells, but the new findings reveal that they also help cells rotate and move about the body.
“While the cell doesn’t have eyes or a sense of smell, its surface is equipped with ultra-slim filopodia that resemble entangled octopus tentacles. These filopodia help a cell move towards a bacterium, and at the same time, act as sensory feelers that identify the bacterium as a prey,” explains Associate Professor Poul Martin Bendix, head of the laboratory for experimental biophysics at the Niels Bohr Institute (NBI), in a university release.
Using a microscope, NBI researchers watched a cell push towards a bacterium, tracking it down like a predator hunts prey. The immune cell eventually made its way to the bacterium and devoured it. Understanding how cells use their tentacles for movement could help scientists figure out how to keep cancer cells from invading neighboring tissues and spreading the disease.
“Obviously, our results are of interest to cancer researchers. Cancer cells are noted for their being highly invasive. And, it is reasonable to believe that they are especially dependent on the efficacy of their filopodia, in terms of examining their surroundings and facilitating their spread. So, it’s conceivable that by finding ways of inhibiting the filopodia of cancer cells, cancer growth can be stalled,” Bendix adds.
Cancer cells are like microscopic rubber bands
Researchers say the filopodia move cells around in much the same way that rubber bands react when you stretch them. Untwisted, rubber bands have no power. However, when you twist them, the rubber contracts. The same things happen in cells, helping them to change direction while keeping the filopodia flexible.
“They’re able to bend — twist, if you will — in a way that allows them to explore the entire space around the cell, and they can even penetrate tissues in their environment,” says lead author Natascha Leijnse.
It’s not just cancer cells which have this ability, all cells do. Study authors say that makes their discovery equally important for researchers doing work with embryonic stem cells and brain cells. The team notes that both of these types of cells are highly dependent on filopodia during their development.
World’s greatest tweezers helped make the discovery
Scientists say these aren’t the kind of tweezers you’re going to find at your local pharmacy. Researchers were able to make their breakthrough by using a device called optical tweezers.
With objects as small as cells, it’s impossible to pick one up using a normal tool. The optical tweezers, however, can hold and move microscopic objects using a laser beam. Scientists carefully adjust the beam’s wavelength to match the object they’re studying, making it capable of pushing cells around.
“At NBI, we have some of the world’s best optical tweezers for biomechanical studies. The experiments require the use of several optical tweezers and the simultaneous deployment of ultra-fine microscopy,” Bendix explains.
The study is published in the journal Nature Communications.