Octopus-like tentacles help cancer cells invade the body – New knowledge about a fundamental mechanism in all living cells
With the help of some of the best tweezers in the world, a team of researchers from the University of Copenhagen has shed new light on a fundamental mechanism in all living cells that helps them explore their environment and even invade tissues. Their discovery could have implications for cancer research, neurological disorders and more.
Using octopus-like tentacles, a cell pushes toward its target, a bacterium, like a predator that monitors its prey. The scene could be played on a nature program. In contrast, nanoscale tracking is observed under a microscope at the Niels Bohr Institute at the University of Copenhagen. Microscopic recording shows a human immune cell chasing and then devouring a bacterium.
In their new study, a team of Danish researchers added to the world understanding of how cells use octopus-like tentacles called filopodia to move around our bodies. This discovery about how cells move has never been addressed. The study is published today (March 28, 2022) in the renowned journal Nature Communications.
“While the cell has no eyes or smell, its surface is equipped with extremely thin legs that look like tangled octopus tentacles. “These pods help a cell move to a bacterium and at the same time act as sensors that recognize the bacterium as prey,” said Poul Martin Bendix, an associate professor at the Niels Bohr Institute for Experimental Biophysics.
The mechanical operation of the footrest can be compared to a tire. Without twisting, a tire has no power. But if you turn it, it shrinks. This combination of twisting and contraction helps a cell move in a directional direction and makes the foot very flexible. The mechanism discovered by Danish researchers seems to be found in all living cells. In addition to cancer cells, it is also important to study the importance of philopods in other cell types, such as embryonic stem cells and brain cells, which are highly dependent on philopods for their growth.
The discovery is not that the limbs function as sensory devices – something that was already well established – but rather about how they can rotate and behave mechanically, something that helps a cell move, like when a cancer cell invades new tissue.
“Obviously, our results are of interest to cancer researchers. Cancer cells are known to be extremely invasive. And, it is reasonable to assume that they are highly dependent on the effectiveness of their limbs in examining their environment and facilitating their spread. “Thus, it is understandable that by finding ways to inhibit the cytoplasm of cancer cells, the growth of cancer can be stopped,” explains Associate Professor Poul Martin Bendix.
For this reason, researchers from the Danish Cancer Society Research Center are part of the team behind the discovery. Among other things, cancer researchers are interested in whether inactivating the production of certain proteins can inhibit the transport mechanisms that are important for the cytoplasm of cancer cells.
The cell motor and the cutting lens
According to Poul Martin Bendix, the mechanical operation of the footrests can be compared to a tire. Without twisting, a tire has no power. But if you turn it, it shrinks. This combination of twisting and contraction helps a cell move in a directional direction and makes the foot very flexible.
“They can bend – twist, if you will – in a way that allows them to explore the entire space around the cell and can even penetrate the tissues around them,” says lead author Natascha Leijnse.
The mechanism discovered by Danish researchers seems to be found in all living cells. In addition to cancer cells, it is also important to study the importance of philopods in other cell types, such as embryonic stem cells and brain cells, which are highly dependent on philopods for their growth.
Cell study with the best tweezers in the world
The project involved an interdisciplinary collaboration at the Niels Bohr Institute, where Associate Professor Amin Doostmohammadi, who heads a research team that simulates biologically active materials, helped model the behavior of the foot.
“It is very interesting that Amin Doostmohammadi was able to simulate the mechanical movements we saw through the microscope, completely independent of chemical and biological details,” explains Poul Martin Bendix.
The main reason the team was the first to describe the mechanical behavior of filopodia is that the NBI has unique equipment for this type of experiment, as well as skilled researchers with vast experience working with optical tweezers. When an object is extremely small, holding it mechanically becomes impossible. However, it can be held and moved using a laser beam with a wavelength carefully calibrated to the object under study. These are called optical tweezers.
“At NBI, we have some of the best optical tweezers in the world for biomechanical studies. “Experiments require the use of multiple optical forceps and the simultaneous development of ultra-thin microscopy,” explains Poul Martin Bendix.
Reference: “Filopodia rotates and coil actively creating twist on their actin axis” March 28, 2022, Nature Communications.DOI: 10.1038 / s41467-022-28961-x.
The study, led by Poul Martin Bendix and Assistant Professor Natascha Leijnse, was led by NBI technician Younes Barooji. The article on the cell pod is published today in Nature Communications.
March 28, 2022
