Newly discovered waste sorting protects our genes

In a series of new results, researchers from the Danish Cancer Society give a completely new explanation of why normal cells turn into cancer cells. The results have just been published in the scientific journal Nature Communications


Satellites (in red) are engulfed in the waste-disposal of the cell (in green). On the bottom left, schematic of the centrosome surrounded by the satellites

In many ways, our cells can be compared to a factory. At the center of the factory is a work plan - our genes - describing how the factory should be managed. The genes ensure that the factory works properly, producing the products it is meant to. And because the genes are so important, there is a comprehensive safety system keeping track of errors and adoptijg strategies to limit them. 

This is the safety system that new research from the Danish Cancer Society has now given a completely new insight into. More specifically, the research shows how the system uses a hitherto unknown form of waste system to maintain the genes. 

- It has long been known that the body's cells have a general waste disposal system, but it is quite new that there is actually a system specifically designed to protect our genes and keep them stable. Genetic instability is one of the most important ways a normal cell turns into a cancer cell, and we are thus in possession of knowledge that is universal for the development of cancer across many cancer types. So says research leader and professor Francesco Cecconi, who has led the team of scientists at the Cancer Society. 

Although the researchers emphasize that much more research is needed in the field, they hope that in the longer run, the research can provide knowledge about new potential targets for the treatment of cancer.

Genetic material is distributed during cell division

When cells divide, everything in the cell's interior must also double, so that two new, identical cells emerge from the division. In that process, our genetic material must also be shared and distributed with a complete copy in each cell. 

Responsible for the distribution of the genetic material are the so-called centrosomes. Their function is to pull the two parts of the genetic material into each new cell. 

Cancer cells often have defects in the centrosomes, but so far little is known about how the defects occur or how the centrosomes are maintained and repaired. 

This is where the newly described waste system comes into play, since this system is maintaining the centrosomes. Specifically, it ensures that cellular structures that are crucial in the maintenance of the centrosome are regularly broken down and replaced, so that the centrosomes constantly function optimally.

Satellites give name to new system

One of the things that comes with being the first in the world to describe a new phenomenon is the right to name the new discovery. Here, the researchers have called the new waste management system for doryphagy. It comes from the Greek word "doryfóros" which means satellite. 

The word is chosen because the new waste system specifically focuses on cellular structures, which lie like small satellites around the centrosome.

The results are published here: Selective autophagy maintains centrosome integrity and accurate mitosis by turnover of centriolar satellites. Nature Communications (Online September 13, 2019).

The researchers collaborate

The new research was first-authored by Søs Grønbæk Holdgaard and created in a collaboration between researchers from the Danish Cancer Society's Center for Autophagy, Recycling and Disease (CARD), which is supported by the Danish Fund for Research.